State v. Darryl Nieves; State v. Michael Cifelli

SYLLABUS

This syllabus is not part of the Court’s opinion. It has been prepared by the Office

of the Clerk for the convenience of the reader. It has been neither reviewed nor

approved by the Court and may not summarize all portions of the opinion.

State v. Darryl Nieves (A-26/27-23) (088683)

Argued October 21, 2024 -- Decided November 20, 2025

JUSTICE PIERRE-LOUIS, writing for the Court.

In this appeal, the Court considers whether expert testimony regarding Shaken

Baby Syndrome/Abusive Head Trauma (SBS/AHT) is sufficiently reliable to go

before a jury in two separate cases -- State v. Nieves and State v. Cifelli.

In both matters, the young children exhibited symptoms that have come to be

associated with SBS/AHT and referred to as the “triad of symptoms” -- subdural

hematoma, retinal hemorrhages, and encephalopathy. In both cases, the same doctor

determined that the children were victims of child abuse, specifically SBS/AHT.

Because the children were in the care of their fathers when they began to exhibit the

above-mentioned symptoms, both men were charged with criminal offenses.

The State sought to present the expert testimony of a doctor that the only

explanation for the children’s symptoms, to a reasonable degree of medical

certainty, was that the children were shaken by the caregiver. The defense in both

cases moved to exclude the testimony, challenging the scientific basis and reliability

of the theory that shaking alone, without some other impact to the head, can cause

the symptoms associated with SBS/AHT.

After a hearing to explore the admissibility of the evidence in Nieves,

reviewed in detail on pages 29-57 of the Court’s opinion, the trial court excluded

SBS/AHT testimony from the trial. The trial court in Cifelli followed suit. The

appeals were consolidated and the Appellate Division affirmed. The Court granted

certification in Nieves and leave to appeal in Cifelli. 256 N.J. 451 (2024).

HELD: The Court agrees with the trial courts and Appellate Division that the State

has not met its burden in establishing the reliability of SBS/AHT testimony here.

1. The Court reviews the history of SBS/AHT over the past six decades (pp. 9-26):

• In 1968, neurosurgeon Dr. Ayub Ommaya conducted an experimental study

focused specifically on whiplash injuries from car accidents. Although Dr.

Ommaya’s study did not concern head trauma in infants from shaking, it

1

became a foundation for diagnoses of SBS/AHT, particularly its conclusion

that brain injuries could occur by rotational displacement of the head on the

neck alone, without significant direct head impact.

• In 1971, neurosurgeon Dr. Arthur Norman Guthkelch presented the theory of

SBS, partially relying on Dr. Ommaya’s 1968 study. Dr. Guthkelch

hypothesized that an “infant having been shaken rather than struck by its

parent” might sustain a subdural hematoma.

• In 1972 and 1974, pediatric radiologist Dr. John Caffey published papers on

“whiplash-shaking” of infants, relying on historical cases and Dr. Ommaya’s

study. In comparing the force of infant shaking with the force generated

during a car accident whiplash event, Dr. Caffey stated -- without elaboration

or citation -- that manual shaking, when repeated, “may be much more

harmful to the brain” and “the veins in the eyes” than a car accident whiplash

event” and that “[c]urrent evidence, though manifestly incomplete and largely

circumstantial, warrants a nationwide educational campaign” on the potential

risks of whiplash shaking of infants. In the years following Dr. Caffey’s 1974

study, the theory of whiplash infant shaking syndrome, later referred to as

shaken baby syndrome, began to gain traction in the medical community.

• In 1987, Dr. Ann-Christine Duhaime, using infant models, conducted the first

biomechanical study testing shaken baby syndrome and the effects of shaking

without impact. Dr. Duhaime concluded that shaking alone does not produce

shaken baby syndrome.

• In 2002, Dr. Ommaya, whose whiplash study was the basis for Dr.

Guthkelch’s conclusions and Dr. Caffey’s whiplash shaken infant syndrome

hypothesis, published a study criticizing other researchers’ reliance on his

own study as the scientific foundation of SBS. A decade later, Dr. Guthkelch

also questioned the science behind SBS.

• In 2018, while the SBS/AHT debate continued, a group of physicians and

pediatric radiologists published a Consensus Statement on AHT, which the

American Academy of Pediatrics later endorsed. The Consensus Statement

cited to the studies by Dr. Caffey and noted Dr. Caffey’s citation to Dr.

Ommaya and Dr. Guthkelch. It acknowledged Dr. Duhaime’s conclusion that

shaking alone cannot generate the force needed to cause the injuries that result

in SBS/AHT cases but noted that contrary evidence -- confessions by

caregivers -- supports the argument that shaking alone can cause SBS/AHT.

The Consensus Statement also noted that SBS/AHT is a medical diagnosis,

not a legal finding of murder, and declared that “[t]here is no controversy

concerning the medical validity of the existence of AHT.”

2

2. For expert testimony to be admissible under N.J.R.E. 702, its proponent must

establish that (1) the subject matter of the testimony is beyond the ken of the average

juror; (2) the field of inquiry is at a state of the art such that an expert’s testimony

could be sufficiently reliable; and (3) the witness has sufficient expertise to offer the

testimony. During the relevant period, New Jersey courts relied on the standard set

forth in Frye v. United States, 293 F. 1013 (D.C. Cir. 1923), to assess the reliability

prong. The Frye standard requires trial courts to determine whether the science

underlying the proposed expert testimony has gained general acceptance in the

particular field in which it belongs. In certain circumstances, there might be more

than one relevant scientific community to consider. In Olenowski II, for example,

the Court recognized that the relevant scientific communities in determining the

reliability of Drug Recognition Expert testimony included both medicine and

toxicology. State v. Olenowski (Olenowski II), 255 N.J. 529, 604 (2023). Further,

courts may revisit previously accepted theories as the science develops. In State v.

J.L.G., for example, the Court determined that certain expert testimony regarding

Child Sexual Abuse Accommodation Syndrome no longer met the reliability prong

and was therefore inadmissible in criminal trials because it was based on clinical

practice and not supported by objectively tested scientific evidence. 234 N.J. 265,

272, 291 (2018). (pp. 78-83)

3. Few New Jersey court opinions have addressed the reliability of SBS/AHT, and

none involve the reliability of SBS/AHT in the context of shaking without impact.

However, many cases from around the country in the past 15 years have focused on

the reliability of SBS/AHT, and the Court reviews such cases. (pp. 83-91)

4. Turning to the matters before it, the Court first determines the relevant scientific

community or communities for purposes of SBS/AHT. As the State’s expert

testified, the starting point in the evolution of SBS/AHT was Dr. Ommaya’s 1968

whiplash study, on which Drs. Guthkelch and Caffey later relied in conceptualizing

SBS/AHT. It is therefore evident that the foundation of SBS/AHT lies in

biomechanical science and engineering. A scientific community is either relevant or

not for purposes of determining admissibility of scientific evidence at trial -- degrees

of relevance are not weighed. As in Olenowski II, there can certainly be more than

one relevant scientific community for purposes of Frye. Here, the relevant scientific

communities for purposes of determining the reliability of SBS/AHT expert

testimony are both the medical/pediatric community and the biomechanical

engineering community. (pp. 92-94)

5. The Court next considers whether, under the Frye standard of reliability, the State

has met its burden of establishing that its expert’s testimony regarding SBS/AHT

without impact is sufficiently reliable for admission at trial. Based on the testimony,

evidence, and scientific studies and writings, the State has not met its burden of

clearly establishing general acceptance in the relevant scientific communities

3

because it has not shown general acceptance within the biomechanical community

regarding whether shaking without impact can produce the “triad” of symptoms

associated with SBS/AHT. The record established in the Frye hearing regarding the

challenges to the science behind SBS/AHT in these matters questions the scientific

and biomechanical underpinnings of the diagnosis of SBS/AHT as the sole basis for

a legal finding of child abuse. As the trial court found, the evidence presented at the

Frye hearing -- including the testimony by the State’s single expert witness --

showed that there was no test supporting a finding that humans can produce the

physical force necessary to cause the symptoms associated with SBS/AHT in a child.

There is evidence of general acceptance by many in the medical community, but the

State must also establish general acceptance in the biomechanical community, and it

has failed to do so. (pp. 94-107)

6. The Court explains that if there is physical evidence of trauma to a child or other

evidence of abuse, the State can present such evidence to a jury. And if new,

reliable, scientific evidence is developed, the State can, in a future case, make a

showing under the Daubert standard adopted in State v. Olenowski (Olenowski I),

253 N.J. 133, 139, 155 (2023), that expert testimony regarding SBS/AHT without

impact is reliable. In such a case, scientific evidence and research, both old and

new, could be presented and considered. (p. 108)

AFFIRMED.

JUSTICE WAINER APTER, dissenting, stresses that SBS/AHT has been

explicitly affirmed by every major discipline involved in its diagnosis and treatment

and expresses the view that the Court here substitutes its judgment for that of the

relevant scientific community. Justice Wainer Apter writes that, in the few prior

instances in which the Court determined that evidence did not satisfy the Frye

standard, the evidence lacked the endorsement of even one major scientific

association or society, whereas SBS/AHT is endorsed by all of them. Further,

Justice Wainer Apter notes, every other state admits expert testimony diagnosing

SBS/AHT, and every other court that has considered the question has held that such

evidence is admissible. Justice Wainer Apter writes that the majority has allowed

individual biomechanical engineers to veto the consensus perspective of every major

medical society in the world -- in a case about the admissibility of a medical

diagnosis. Justice Wainer Apter would leave it to the jury to weigh the experts’

competing testimony.

CHIEF JUSTICE RABNER and JUSTICES PATTERSON, FASCIALE,

NORIEGA, and HOFFMAN join in JUSTICE PIERRE-LOUIS’s opinion.

JUSTICE WAINER APTER filed a dissent.

4

SUPREME COURT OF NEW JERSEY

A-26/27 September Term 2023

088683

State of New Jersey,

Plaintiff-Appellant,

v.

Darryl Nieves,

Defendant-Respondent.

State of New Jersey,

Plaintiff-Appellant,

v.

Michael Cifelli,

Defendant-Respondent.

On certification to and appeal from the Superior

Court, Appellate Division, whose opinion is reported

at 476 N.J. Super. 609 (App. Div. 2023).

Argued Decided

October 21, 2024 November 20, 2025

David M. Liston, Assistant Prosecutor, argued the cause

for appellant State of New Jersey (Yolanda Ciccone,

Middlesex County Prosecutor, attorney; David M. Liston,

of counsel and on the briefs).

1

Cody T. Mason, Deputy Public Defender II, argued the

cause for respondent Darryl Nieves (Jennifer N. Sellitti,

Public Defender, attorney; Cody T. Mason, of counsel

and on the briefs).

Philip Nettl argued the cause for respondent Michael

Cifelli (Benedict Altman and Nettl, attorneys; Philip

Nettl, on the briefs).

Elizabeth H. Wallace, Deputy Attorney General, argued

the cause for amici curiae Attorney General of New

Jersey and New Jersey Division of Child Protection and

Permanency (Matthew J. Platkin, Attorney General,

attorney; Jeremy M. Feigenbaum, Solicitor General,

Angela Cai, Deputy Solicitor General, Sookie Bae-Park,

Assistant Attorney General, and Steven A. Yomtov,

Deputy Attorney General, of counsel, and Elizabeth H.

Wallace, Regina M. Oberholzer, Deputy Attorney

General, and Christopher Ioannou, Deputy Attorney

General, on the brief).

T. Gary Mitchell, Deputy Public Defender, argued the

cause for amicus curiae Public Defender of New Jersey,

Office of Parental Representation (Jennifer N. Sellitti,

Public Defender, attorney; T. Gary Mitchell, of counsel

and on the brief).

Kelly S. Crawford submitted a letter in lieu of a brief on

behalf of amici curiae The Innocence Network and

Center for Integrity in Forensic Sciences (Riker Danzig,

attorneys).

Audra J. Soloway (Paul, Weiss, Rifkind, Wharton &

Garrison) submitted a brief on behalf of amici curiae Dr.

Jacob Andersson, Prof. Anders Eriksson, Dr. John

Galaznik, Dr. Patrick Hamel, Dr. Ulf Högberg, Dr.

Lawrence Hutchins, Dr. Charles J. Hyman, Prof. Niels

Lynøe, Dr. Marvin Miller, Dr. David Ramsay, Dr. Cyrille

Rossant, Dr. Robert K. Rothfeder, Dr. Irene Scheimberg,

Dr. Joseph Scheller, Dr. Guillaume Sébire, Dr. Waney

2

Squier, Dr. Dale Vaslow, Dr. Knut Wester, and Dr. R.K.

Wright (Paul, Weiss, Rifkind, Wharton & Garrison, and

Innocence Project, Inc., attorneys; Audra J. Soloway, of

counsel and on the brief, and David Cole (Paul, Weiss,

Rifkind, Wharton & Garrison) of the Massachusetts bar,

admitted pro hac vice, Carter E. Greenbaum (Paul, Weiss,

Rifkind, Wharton & Garrison) of the New York and

California bars, admitted pro hac vice, and Tania Brief

(Innocence Project, Inc.) of the New York bar, admitted

pro hac vice, on the brief).

Lawrence S. Lustberg submitted a brief on behalf of

amici curiae Lindsay “Dutch” Johnson, Ph.D., Ken

Monson, Ph.D., Kirk Thibault, Ph.D., D-IBFES, Keith

Button, Ph.D., PE, and Johan Ivarsson, Ph.D. (Gibbons,

attorneys; Lawrence S. Lustberg and Ruth O’Herron, on

the brief).

CJ Griffin submitted a brief on behalf of amici curiae Dr.

Jeff Kukucka, Ph.D., Keith A. Findley, Esq., Dr. Deborah

Davis, Ph.D., and Dan Simon, Esq. (Pashman Stein

Walder Hayden, attorneys; CJ Griffin, Claude Caroline

Heffron, Christian Martinez, and Dominique Kilmartin,

on the brief).

Mary Beth Hogan submitted a brief on behalf of amici

curiae Family Justice Resource Center, upEND

Movement, MJCF Coalition, and Mothers Outreach

Network (Debevoise & Plimpton, attorneys; Mary Beth

Hogan, on the brief).

Alexandra S. Jacobs (Montgomery McCracken Walker &

Rhoads) submitted a brief on behalf of amici curiae

American Academy of Pediatrics, New Jersey State

Chapter of the American Academy of Pediatrics,

American Association for Pediatric Ophthalmology and

Strabismus, American Society of Pediatric

Neurosurgeons, American Society of Pediatric

Neuroradiology, American Professional Society on the

Abuse of Children, Society for Pediatric Radiology, and

3

The Ray E. Helfer Society (Montgomery McCracken

Walker & Rhoads, and Kienbaum Hardy Viviano Pelton

& Forrest, attorneys; Alexandra S. Jacobs, of counsel and

on the brief, and David Porter (Kienbaum Hardy Viviano

Pelton & Forrest) of the Michigan bar, admitted pro hac

vice, on the brief).

David M. Goodman submitted a brief on behalf of amici

curiae Dr. Richard A. Leo, Dr. Hayley Cleary, Dr. Kyle

Scherr, Dr. Lucy Guarnera, Dr. Saul Kassin, Dr. Lindsay

Malloy, Dr. Christian Meissner, Dr. Allison Redlich, and

Dr. Melissa Russano (Simpson Thacher & Bartlett,

attorneys; David M. Goodman, and Matthew C. Penny of

the New York bar, admitted pro hac vice, on the brief).

Richard P. Lomurro submitted a brief on behalf of amicus

curiae Association of Criminal Defense Lawyers of New

Jersey (Lomurro Munson, attorneys; Richard P. Lomurro,

and Christina Vassiliou Harvey, of counsel and on the

brief, and Andrew B. Broome, on the brief).

JUSTICE PIERRE-LOUIS delivered the opinion of the Court.

Table of Contents

I. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

II. HISTORY OF SBS/AHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

III. FACTS & PROCEDURAL HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . 26

A. State v. Nieves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

1. Facts and Pre-Hearing Proceedings . . . . . . . . . . . . . . . . . . . . . . . . 27

2. The Frye Hearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

3. Trial Court Opinion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

B. State v. Cifelli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

4

C. Consolidated Appellate Division Decision . . . . . . . . . . . . . . . . . . . . . 64

D. Review and Amicus Participation Granted . . . . . . . . . . . . . . . . . . . . . 68

IV. PARTIES’ ARGUMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

A. State of New Jersey and Amici Supporting the State’s Position . . . . . 69

B. Nieves and Cifelli and Amici Supporting Their Position . . . . . . . . . . .72

V. LEGAL STANDARDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

A. Standard of Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

B. Expert Testimony . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

C. Case Law Addressing SBS/AHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

VI. ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

A. The Relevant Scientific Communities . . . . . . . . . . . . . . . . . . . . . . . . 92

B. Application of the Frye Standard of Reliability . . . . . . . . . . . . . . . . . 94

VII. CONCLUSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

I. INTRODUCTION

Many crimes grip the hearts and minds of the public due to their cruel

and heinous nature. The abuse of children, some of the most vulnerable

members of our society, is certainly such a crime. Child abuse is, without

question, reprehensible.

Regardless of the severity or viciousness of a crime, however, the

bedrock foundations and protections embedded within our system of criminal

justice must prevail. Under one of those core principles, only evidence that is

sufficiently reliable and has probative value not outweighed by the evidence’s

5

prejudicial effect may be presented to the jurors to inform their consideration

of the charges against the accused.

That requirement extends to expert testimony, which must be properly

admitted like all evidence. “[T]he Judiciary must ensure that proceedings are

fair to both the accused and the victim. Trial judges partly fulfill that

responsibility by serving as a gatekeeper.” State v. J.L.G., 234 N.J. 265, 307

(2018). Pursuant to N.J.R.E. 702, judges “must assess whether expert

testimony is sufficiently reliable before it can be presented to a jury.” Id. at

308. “Given an expert witness’s singular status in the courtroom,” State v.

J.R., 227 N.J. 393, 411 (2017) -- an expert witness is presented as having been

deemed, by the court, sufficiently knowledgeable to offer testimony beyond

the specifics of a particular case -- legislatures and courts have developed

particular inquiries to assess the admissibility of proposed expert testimony.

The standard to admit expert testimony that governed at time of the

proceedings in this case was the standard set forth in Frye v. United States,

293 F. 1013 (D.C. Cir. 1923). 1 Under the Frye standard, such testimony must

1

In Olenowski I, this Court rejected the Frye standard and adopted “principles

similar to the standard outlined in Daubert [v. Merrell Dow Pharms., Inc., 509

U.S. 579 (1993)] to examine the admissibility of expert evidence in criminal

and quasi-criminal cases.” State v. Olenowski (Olenowski I), 253 N.J. 133,

139, 155 (2023). Criminal matters that originated and were ruled upon before

Olenowski I, such as this one, are nonetheless governed by the Frye standard

6

not only be reliable, but its proponent must establish that the information to

which the expert will testify is generally accepted in the relevant community to

which the expertise belongs.

In this appeal, we are asked to determine whether expert testimony

regarding Shaken Baby Syndrome/Abusive Head Trauma (SBS/AHT) 2 is

sufficiently reliable to go before a jury in two separate cases. In both matters,

the young children exhibited symptoms that have come to be associated with

SBS/AHT and referred to as the “triad of symptoms” -- subdural hematoma,

retinal hemorrhages, and encephalopathy. In both cases, after the children

to assess the reliability prong. Id. at 154 (“Nothing in today’s decision

disturbs prior rulings that were based on the Frye standard.”).

2

Although Shaken Baby Syndrome “is a term often used by physicians and

the public to describe abusive head trauma inflicted on infants and young

children,” the American Academy of Pediatrics (AAP), in 2009, changed the

name from Shaken Baby Syndrome to Abusive Head Trauma because

“advances in the understanding of the mechanisms and clinical spectrum of

injury associated with abusive head trauma compel[led the AAP] to modify

[its] terminology to keep pace with . . . understanding of pathological

mechanisms” of injury. Cindy W. Christian, Robert Block, & Comm. on Child

Abuse & Neglect, Abusive Head Trauma in Infants and Children, 123

Pediatrics 1409, 1409 (2009). According to the AAP, it adopted the term AHT

“in recognition of the fact that inflicted head injury of children can involve a

variety of biomechanical forces, including shaking.” Sandeep K. Narang et al.,

Abusive Head Trauma in Infants and Children, 145 Pediatrics Apr. 2020, at 1,

1. The AAP noted that it “continues to embrace the ‘shaken baby syndrome’

diagnosis as a valid subset of the AHT diagnosis.” Ibid. As such, throughout

this opinion we use the combined term SBS/AHT. In discussing the history of

SBS/AHT, we use the terminology in use at the time.

7

were examined by various medical specialists and a series of tests were run,

the same doctor determined that the children were victims of child abuse,

specifically SBS/AHT. Because the children were in the care of their fathers

when they began to exhibit the above-mentioned symptoms, both men were

charged with criminal offenses, including aggravated assault and child

endangerment.

The State sought to present the expert testimony of a doctor who opined,

based on her findings, that the only explanation for the children’s symptoms,

to a reasonable degree of medical certainty, was that the children were shaken

by the caregiver. That is, the anticipated testimony to the jury would be that,

based on the expert’s medical evaluation of the child, the child was abused.

The defense in both cases moved to exclude the doctor’s expert

testimony, challenging the scientific basis and reliability of the theory that

shaking alone, without some other impact to the head, can cause the symptoms

associated with SBS/AHT. Defendants argued that the scientific community

no longer accepts that theory. After a Frye hearing, the trial court in one

matter granted the defense motion and excluded SBS/AHT testimony from the

trial. The second trial court followed suit. The appeals were consolidated and

the Appellate Division affirmed.

8

For all the reasons that follow, we agree with the trial courts and

Appellate Division that the State has not met its burden in establishing the

reliability of SBS/AHT testimony in this case, and we affirm the Appellate

Division’s judgment.

II. HISTORY OF SBS/AHT

Before detailing the facts and procedural history of the matters before

us, we provide the following background on the origins and evolution of

SBS/AHT over the past six decades.

In 1968, neurosurgeon Dr. Ayub Ommaya conducted an experimental

study focused specifically on whiplash injuries from car accidents. Although

Dr. Ommaya’s study did not concern head trauma in infants from shaking, it

became a foundation for diagnoses of SBS/AHT, particularly its conclusion

that brain injuries could occur “by rotational displacement of the head on the

neck alone, without significant direct head impact.” Ayub K. Ommaya et al.,

Whiplash Injury & Brain Damage: An Experimental Study, 204 J. Am. Med.

Ass’n. 285, 285 (1968).

In the study, Dr. Ommaya subjected monkeys to a whiplash event that

mimicked rear-end car collisions. Id. at 286. Specifically, anesthetized

monkeys were secured to a carriage on roller-skate type wheels, equipped with

a braking mechanism, that could move freely along a 20-foot-long track. Ibid.

9

In delivering controlled blows to the rear of the carriage, the sudden impact

produced “high accelerations of the carriage and forward-facing monkey so as

to mimic a rear-end collision.” Ibid. The carriage was accelerated to a speed

of 30 miles per hour. 3 The whiplash that resulted was recorded by “a high-

speed, 16-mm movie camera at 1,000 frames/sec.” and the “rotational velocity

and acceleration” of the monkeys’ heads were calculated. Ibid.

Even though the monkeys did not sustain significant direct head impact

during the whiplash event, Dr. Ommaya concluded that whiplash “without

direct impact to the head” can cause concussions and “produce consistent brain

damage in the monkey as evidenced by subarachnoid and subdural hemorrhage

[and] cerebral contusions.” Id. at 285. Dr. Ommaya’s study determined that

“it is a matter of crucial importance that we investigate and manage the clinical

problems of whiplash injuries” because whiplash injuries “may be of

significant importance in producing the effects of closed-head injuries under

conditions when the head is free to move.” Id. at 289.

3

Although the acceleration speed was not specifically noted in the 1968

study, Dr. Ommaya clarified in a later study, discussed more fully below, that

the energy level of acceleration in the whiplash study “related to speeds at

motor vehicle crashes at 30 mph.” A. K. Ommaya et al., Biomechanics and

Neuropathology of Adult and Paediatric Head Injury, 16 Brit. J. of

Neurosurgery 220, 221 (2002).

10

In 1971, neurosurgeon Dr. Arthur Norman Guthkelch presented the

theory of SBS, partially relying on Dr. Ommaya’s 1968 study. See A.N.

Guthkelch, Infantile Subdural Haematoma and its Relationship to Whiplash

Injuries, 2 Brit. Med. J. 430, 430 (1971). Dr. Guthkelch hypothesized that an

“infant having been shaken rather than struck by its parent” might sustain a

subdural hematoma. Ibid.

Dr. Guthkelch studied “[t]wenty-three cases of proved or strongly

suspected parental assault on children all under the age of 3 years.” Ibid.

Subdural bleeding was present in 13, and in five cases no external marks of

injury to the head were present. Id. at 430-31. Dr. Guthkelch concluded that

“in considering any case of infantile subdural haematoma, even when there are

only trivial bruises or indeed no marks of injury at all,” one must inquire as to

whether “the baby’s head could have been shaken.” Id. at 431. Dr. Guthkelch

stated that the most common cause of subdural hemorrhages in infants is the

rupturing of one or more of the bridging veins which run from the cerebral

cortex (the outermost layer of gray matter in the brain) to the venous sinuses,

id. at 430, which drain deoxygenated blood from the brain. Dr. Guthkelch

posited that this rupture could occur as a result of both impact and non-impact

events involving the head. Ibid.

11

Dr. Guthkelch did not conduct any scientific studies in support of his

hypothesis, save for an experiment using a round-bottomed glass flask filled

with fluid and desiccated coconut, which he both shook and struck, in order to

observe the movement of the coconut in response to those actions. See id. at

431. Dr. Guthkelch analogized his observations to Dr. Ommaya’s

determinations regarding the movement of the brain in monkeys subjected to a

whiplash event. Ibid. Dr. Guthkelch further credited Dr. Ommaya’s study

with giving him the idea to construct the round-bottomed flask device that

informed his study and conclusions. Ibid.

In 1972, pediatric radiologist Dr. John Caffey published a paper in

which he studied 27 cases believed to involve the shaking of infants or

“whiplash-shaking,” as he termed the action. John Caffey, On the Theory and

Practice of Shaking Infants: Its Potential Residual Effects of Permanent Brain

Damage and Mental Retardation, 124 Am. J. Diseases Child. 161, 161, 164

(1972). Dr. Caffey, citing to four of his own previous papers, noted that

“[d]uring the last 25 years, substantial evidence, both manifest and

circumstantial, has gradually accumulated which suggests that the whiplash-

shaking and jerking of abused infants are common causes of” trauma to the

skeleton and brain. Id. at 161.

12

Dr. Caffey did not conduct any biomechanical experiments himself.

Instead, to arrive at his conclusions, he reviewed historical cases in which

“whiplash-shaking” was suspected. See id. at 163-64. One such case -- for

which he cited to an article in Newsweek -- involved a nurse who was

“reported to have killed three infants and maimed 12 others . . . largely by

shaking and jolting infantile brains and their blood vessels” via whiplash-

shaking and “pounding on the back during burping.” Id. at 163. Dr. Caffey

also cited Dr. Guthkelch’s 1971 study for examples of admitted shaking by a

caregiver where subdural hematoma, retinal hemorrhages, and a broken femur

were present. Ibid. Several of the cases Dr. Caffey studied involved shaking

with impact, including one child’s head banging against her crib during a

shaking incident and another child being “shaken and beaten to death with a

stick.” Ibid.

Dr. Caffey’s study also cited cases of infant bone fractures and included

numerous x-ray images of unexplained fractures of infant femurs, ankles, and

arms. Id. at 162-64. In one case, an infant’s unexplained swelling and trauma

to his legs was revealed to have resulted from his own brother when the

parents saw the eight-year-old brother seize his infant sibling by the legs,

“sh[ake] him violently, and sw[i]ng him, and fl[i]ng him onto a bed.” Id. at

164. The study does not explain whether the infant suffered cranial injuries or

13

subdural hematomas as a result and noted only the trauma to the infant’s

femurs. Id. at 163-64.

In his study, Dr. Caffey also noted that “[t]here are several apparently

innocent, accepted, habitual practices, other than intentional shaking and

jerking, which whiplash the head and brain, and which could lead to permanent

brain damage.” Id. at 165. Dr. Caffey listed a number of activities that can

result in subdural hematomas in infants, including “tossing the baby into the

air,” spinning an infant around, and flipping an infant so that the infant is

somersaulted forward while someone is holding the child’s wrists. Ibid. The

study also recommended that certain toys and equipment, such as baby

bouncers; infant jumpers; seesaws; play slides; “powered cradles and powered

rocking horses; trampolines; skateboards[;] and sled jumping,” should be more

carefully assessed for their dangerousness or banned entirely for infants and

young children. Ibid.

Dr. Caffey posited that whiplash-shaking possibly played a role in other

diagnoses including “cerebral palsies and idiopathic epilepsy” and concluded

that “[t]here is considerable manifest and much circumstantial evidence which

indicates that whiplash-shaking and jolting of infantile heads may be major,

unrecognized causes of mental retardation and permanent brain damage.” Id.

at 168-69. Dr. Caffey concluded his paper by suggesting that “[t]he wide

14

practice of habitual whiplash-shaking for trivial reasons warrants a massive

nationwide educational campaign to alert everyone responsible for the welfare

of infants on its potential and actual pathogenicity.” Id. at 169. Again, Dr.

Caffey did not conduct any biomechanical experiments of his own in support

of that study and relied on the review of cases from other studies, including

Dr. Guthkelch’s 1971 study.

In 1974, Dr. Caffey authored another study in which he coined the

phrase “whiplash shaken infant syndrome.” John Caffey, The Whiplash

Shaken Infant Syndrome: Manual Shaking by the Extremities with Whiplash-

Induced Intracranial and Intraocular Bleedings, Linked with Residual

Permanent Brain Damage and Mental Retardation, 54 Pediatrics 396, 396

(1974). In that study, Dr. Caffey reviewed purported “[d]irect evidence of

trauma through admission by the parent-assailant,” but noted that although

such evidence, “based on admission by the assailant, is meager, it is valuable

because it is reliable.” Id. at 397. With that study, Dr. Caffey identified what

he believed were the “essential elements” of whiplash shaken infant syndrome,

including subdural and retinal hemorrhages, id. at 396, 402, two of the three

symptoms that would later be referred to as the “triad” of symptoms indicative

of shaken baby syndrome.

15

Dr. Caffey once again cited to Newsweek’s account of the infant nurse

as “[b]y far the most extensive anecdotal proof of pathogenic manual

[whiplash shaking]” based on the nurse’s confession to the “savage shakings of

dozens of infants.” Id. at 397. Dr. Caffey again referenced an eight-year-old

sibling who shook his infant brother. See id. at 398. Because no citation was

included for the case, it is unclear whether that is the same case he referred to

in his 1972 article. But in that 1974 paper, Dr. Caffey specifically stated that

subdural hematoma was not detected in that infant. See ibid.

The 1974 study also included incidents not solely related to shaking

without impact, including a case of a father who first attempted to strangle his

infant child and later shook the child to revive them after the infant passed out.

Ibid. In that case, Dr. Caffey concluded that “it is likely that the stresses of

strangling as well as those of manual [whiplash shaking] contributed to the

[infant’s] intraocular changes and possibly the subdural hematomas.” Ibid.

Dr. Caffey further discussed the correlation between retinal hemorrhages

and whiplash shaking. Id. at 400. He noted that one study found that, out of

1,238 newborns, 14% had retinal hemorrhages immediately after birth. Ibid.

According to Dr. Caffey, however, that percentage dropped significantly to

2.6% between the infant’s third and fifth day after birth, indicating that retinal

hemorrhages due to birth disappear rather quickly, as opposed to “retinal

16

hemorrhages in abused infants [that can] persist[] for ten years and in one case

for 19 years.” Ibid. Dr. Caffey concluded that “[t]he preponderance of the

evidence from several sources indicates that the idiopathic retinal hemorrhages

of the newborn infant are not due to trauma at the time of birth and the retinal

hemorrhages found in battered and shaken infants are probably caused by

postnatal manual shaking.” Ibid. (emphases added).

To support his whiplash shaken infant syndrome hypothesis, Dr. Caffey

cited Dr. Ommaya’s 1968 whiplash study. He noted that Dr. Ommaya’s study

found that concussions could occur “by rotational displacement alone of the

head on the neck.” Id. at 402. Dr. Caffey posited that “[r]otation of the head

is of course a consistent additional stress in the manual . . . shaking of infants.”

Ibid.

In comparing the force of infant shaking with the force generated during

a car accident whiplash event, Dr. Caffey stated -- without elaboration or

citation -- that “[i]t is obvious that although the single manual shake of an

infant may be less forceful and pathogenic than the single whiplash in an

automobile accident,” manual shaking, when repeated, nevertheless “may be

much more harmful to the brain” and “the veins in the eyes.” Ibid. He

concluded his paper by stating that “[c]urrent evidence, though manifestly

incomplete and largely circumstantial, warrants a nationwide educational

17

campaign” on the potential risks of whiplash shaking of infants. Id. at 403

(emphasis added). Once again, Dr. Caffey did not conduct any scientific

experiments in that study and relied on anecdotal reported cases and case

studies.

In the years following Dr. Caffey’s 1974 study, the theory of whiplash

infant shaking syndrome, later referred to as shaken baby syndrome, began to

gain traction in the medical community. 4 That acceptance was based almost

entirely on Dr. Guthkelch and Dr. Caffey’s case studies, both of which relied

on Dr. Ommaya’s scientific study as the sole source of experimental scientific

4

There was little research regarding SBS/AHT following Dr. Caffey’s 1974

study until Dr. Duhaime’s in 1987. See Deborah Tuerkheimer, The Next

Innocence Project: Shaken Baby Syndrome and the Criminal Courts, 87 Wash.

U. L. Rev. 1, 12 (2009) (discussing the “new ‘evidence-based medicine’”

standards that led to heightened scrutiny and a resurgence of SBS/AHT related

literature “in the mid- to late-1990s”); Jack R. Shepard et al., Child Abuse and

Exploitation: Investigative Techniques 26-29 (2d ed. 1992) (describing

SBS/AHT); Julie Jonas, Unequal Funding Compounds Tragedy: Failures in

Defending Against Shaken Baby Syndrome Charges, 96 Temp. L. Rev. 135,

148 (2024) (discussing the history of SBS/AHT’s acceptance and noting that

its acceptance was “[b]ased only on the case studies by Dr. Guthkelch and Dr.

Caffey” and Dr. Ommaya’s research); Christian, Block, & Comm. on Child

Abuse & Neglect, 123 Pediatrics at 1409 (explaining the history of

SBS/AHT’s acceptance); Wajd N. Al-Holou et al., Nonaccidental Head Injury

in Children: Historical Vignette, 3 J. Neurosurgery Pediatrics 474, 480-81

(2009) (discussing Dr. Guthkelch’s and Dr. Caffey’s work as the foundation of

SBS/AHT’s acceptance). But see Stephen Ludwig & Matt Warman, Shaken

Baby Syndrome: A Review of 20 Cases, 13 Annals Emergency Med. 104,

104-07 (1984) (reviewing 20 incidents of SBS/AHT).

18

data behind the theory, notwithstanding the fact that Dr. Ommaya’s study had

nothing to do with the shaking of infants. See Sissoko v. State, 182 A.3d 874,

899 (Md. Ct. Spec. App. 2018) (discussing the history of SBS/AHT); see also

Commonwealth v. Martin, 290 S.W.3d 59, 62-63 (Ky. Ct. App. 2008)

(describing testimony that discussed the history of SBS/AHT).

In 1987, Dr. Ann-Christine Duhaime conducted the first biomechanical

study testing shaken baby syndrome and the effects of shaking without impact.

Ann-Christine Duhaime et al., The Shaken Baby Syndrome: A Clinical,

Pathological, & Biomechanical Study, 66 J. Neurosurgery 409, 409 (1987).

The study authors reviewed all cases of SBS at the Children’s Hospital of

Philadelphia (CHOP) from January 1978 to March 1985. Id. at 409-10. Out of

the 48 cases for which clinical data was available, only one involved shaking

without impact, and 15 cases -- the largest percentage -- were cases of

accidental blunt trauma, usually from a fall. Id. at 410. After reviewing the

cases, Dr. Duhaime determined that pathological examinations revealed that

“all of the children who died had evidence of blunt head trauma.” Id. at 411.

Those findings of impact, however, were visible only at the time of autopsy in

seven of the thirteen cases resulting in death because the trauma was not

apparent prior to the children’s deaths. Ibid.

19

Importantly, after conducting a biomechanical study using infant

models, Dr. Duhaime concluded that “shaking alone does not produce the

shaken baby syndrome.” Id. at 409. Dr. Duhaime used infant models and

implanted “an accelerometer to measure the results of shaking or impact

manipulations.” Id. at 411. Dr. Duhaime sought to determine what level of

force, both acceleration and deceleration, is generated by shaking alone and,

separately, by impact to the head. See id. at 413. The models were shaken

violently and repetitively. Ibid. The back of models’ heads were then struck

against a metal bar or a padded surface. Ibid. According to Dr. Duhaime, the

results showed that the acceleration and velocity levels for shaking fell well

below the threshold at which injuries, such as concussions and subdural

hematomas, occurred in previous studies using primates. Id. at 414. The

results further showed that the forces generated as a result of impact fell within

the acceleration and velocity ranges expected in cases in which concussions,

subdural hematomas, and diffuse axonal injury, a type of traumatic brain

injury, were present. 5 Ibid. In short, Dr. Duhaime’s study was not able to

5

Specifically, Dr. Duhaime determined that the average peak acceleration for

the shaking episodes was 9.29 g, whereas the average peak acceleration for the

impact events was 428.18 g, over 50 times more. Id. at 413. A “g” is the

“force of gravity or acceleration on the body.” Merriam-Webster Dictionary,

https://www.merriam-webster.com/dictionary/g-force (last visited Oct 31,

2025).

20

generate, in the infant models, the forces necessary to result in the relevant

brain injuries by shaking alone. See id. at 413-14.

Based on her biomechanical experiment and review of SBS cases at

CHOP, Dr. Duhaime concluded that “shaken baby syndrome, at least in its

most severe acute form, is not usually caused by shaking alone.” Id. at 414.

Dr. Duhaime added that “[a]lthough shaking may, in fact, be a part of the

process, it is more likely that such infants suffer blunt impact. The most

common scenario may be a child who is shaken, then thrown into or against a

crib or other surface, striking the back of the head.” Ibid. (emphasis added).

In 1993, the American Academy of Pediatrics (AAP) released its first

statement on the theory of SBS. Citing in part to both Drs. Guthkelch and

Caffey, the AAP’s statement noted that “data regarding the nature and

frequency of head trauma consistently support a medical presumption of child

abuse when a child younger than 1 year of age has intracranial injury.” Am.

Acad. of Pediatrics, Comm. on Child Abuse & Neglect, Shaken Baby

Syndrome: Inflicted Cerebral Trauma, 92 Pediatrics 872, 872 (1993)

(emphasis added). The AAP’s statement mentioned Dr. Duhaime’s

experimental study, simply noting that “a challenge to the presumption that the

shaking alone is the sole source of the trauma” arose from Dr. Duhaime’s

study. Ibid. The AAP statement related to children believed to have been

21

shaken, with or without impact. Ibid. The statement advised medical

professionals on the clinical features of SBS and the role of specialized

disciplines in recognizing SBS. Id. at 873-74. The statement further

suggested that a diagnostic team of specialists be formed, with medical

professionals in pediatrics, radiology, neurology, neurosurgery, and

ophthalmology. Id. at 874. The AAP’s statement did not discuss the

Guthkelch and Caffey studies in depth and did not mention or cite to Dr.

Ommaya’s 1968 study.

In 2002, Dr. Ommaya, whose whiplash study was the basis for Dr.

Guthkelch’s conclusions and Dr. Caffey’s whiplash shaken infant syndrome

hypothesis, published a study criticizing other researchers’ reliance on his own

study as the scientific foundation of SBS. A.K. Ommaya et al., Biomechanics

and Neuropathology of Adult and Paediatric Head Injury, 16 Brit. J.

Neurosurgery 220 (2002).

Dr. Ommaya cautioned that “[i]t is improbable that the high speed and

severity of the single whiplash produced in our animal model could be

achieved by a single manual shake or even a short series of manual shaking of

an infant in one episode.” Id. at 221. Dr. Ommaya further noted that Dr.

Caffey, Dr. Guthkelch, and others referenced by analogy his 1968 study “not

realizing that the energy level of acceleration in [his] work related to speeds at

22

motor vehicle crashes at 30 mph.” Ibid. Dr. Ommaya acknowledged that “it is

possible that continued repetitive shaking over a period of time, or shaking

repeated at intervals can produce significant cerebral as well as cervical spinal

cord trauma in an infant.” Id. at 225 (emphasis added). Regarding the

biomechanics of retinal hemorrhages, Dr. Ommaya opined that “the levels of

force required for retinal bleeding by shaking to damage the eye directly is

biomechanically improbable,” given that small masses like the eye require

levels of force even higher than larger masses like the brain. Id. at 233.

Significantly, Dr. Ommaya critiqued the assumptions upon which

theories about mechanisms of pediatric retinal and brain injuries in literature

have been based. Id. at 227. Those assumptions included the following: short

falls cannot cause subdural hematomas; retinal hemorrhages result from

shaking; and the time interval between the onset of symptoms as a result of

SBS is always brief. Ibid. Dr. Ommaya stated that “[t]hese assumptions

individually and in concert are ambiguous or incorrect” even though those very

assumptions had been used as the bases for the differential diagnoses of SBS,

“usually without reference to available biomechanical analysis.” Ibid.

A decade after Dr. Ommaya signaled that SBS lacked an underlying

scientific foundation, Dr. Guthkelch, whose study relied on Dr. Ommaya’s

whiplash experiment and was in turn cited by Dr. Caffey, also questioned the

23

science behind SBS. A.N. Guthkelch, Problems of Infant Retino-Dural

Hemorrhage with Minimal External Injury, 12 Hous. J. Health L. & Pol’y 201,

201 (2012). In his article, Dr. Guthkelch noted that the controversy

surrounding SBS/AHT had risen to a level of emotion and divisiveness “that

has interfered with our commitment to pursue the truth.” Ibid.

According to Dr. Guthkelch, his 2012 article, which was not a study,

was “a call for civility in scientific discourse.” Ibid. Dr. Guthkelch identified

several problems with the SBS/AHT theory and concluded that given the

science, it does not follow that “one can infer shaking (or any other form of

abuse) from a finding of retino-dural hemorrhage in infancy.” Id. at 203. Dr.

Guthkelch pointed out that there “seem to have been instances in which both

medical science and the law have gone too far in hypothesizing and

criminalizing alleged acts of violence” when the only evidence was the

presence of the triad of symptoms or just one or two symptoms of the triad.

Id. at 203-04.

Dr. Guthkelch further stated that “SBS and AHT are hypotheses that

have been advanced to explain findings that are not yet fully understood.” Id.

at 207. In acknowledging that there is nothing wrong with advancing

hypotheses, Dr. Guthkelch noted that “[i]t is wrong, however, to fail to advise

parents and courts when these are simply hypotheses, not proven medical or

24

scientific facts, or to attack those who point out problems with these

hypotheses or who advance alternatives. Often, ‘getting it right’ simply means

saying, clearly and unequivocally, ‘we don’t know.’” Ibid.

In 2018, while the SBS/AHT debate continued, a group of physicians

and pediatric radiologists published a consensus statement on AHT (the

Consensus Statement) which the AAP later endorsed. The Consensus

Statement purports to “address[] significant misconceptions and

misrepresentations about the diagnosis of [AHT] in infants and young

children,” noting that, “[r]ecently, denialism of child abuse has become a

significant medical, legal and public health problem.” Arabinda Kumar

Choudhary et al., Consensus Statement on Abusive Head Trauma in Infants

and Young Children, 48 Pediatric Radiology 1048, 1050 (2018). The

Consensus Statement further noted that “the courtroom has become a forum for

speculative theories” regarding SBS/AHT, despite the fact, according to the

Consensus Statement, that “[SBS/]AHT is a scientifically non-controversial

medical diagnosis.” Id. at 1048-49. As a result of what the authors deemed

SBS/AHT “denialists” and the sensationalized critique of SBS/AHT in the

media, the Consensus Statement authors stated that they hoped the document

would reduce confusion and help courts “recognize unsubstantiated medical

expert testimony.” Id. at 1049, 1060.

25

The Consensus Statement cited to the studies by Dr. Caffey and noted

Dr. Caffey’s citation to Dr. Ommaya and Dr. Guthkelch. Id. at 1051. Among

other conclusions, the authors of the Consensus Statement discounted short-

distance falls as a possible cause of subdural hematomas and retinal

hemorrhages. Id. at 1052. They acknowledged Dr. Duhaime’s conclusion that

shaking alone cannot generate the force needed to cause the injuries that result

in SBS/AHT cases but noted that contrary evidence -- confessions by

caregivers -- supports the argument that shaking alone can cause SBS/AHT.

Id. at 1051. The Consensus Statement also noted that SBS/AHT is a medical

diagnosis, not a legal finding of murder, contrary to the arguments of defense

attorneys. Id. at 1059. The Consensus Statement declared quite definitively

that “[t]here is no controversy concerning the medical validity of the existence

of AHT.” Id. at 1048.

III. FACTS & PROCEDURAL HISTORY

We next turn to the facts and procedural history of the two cases that

gave rise to this appeal.

26

A. State v. Nieves 6

1. Facts and Pre-Hearing Proceedings

Respondent Darryl Nieves is the father of D.J., who was born

prematurely at 25 weeks due to complications his mother experienced during

her pregnancy. After his birth in March 2016, D.J. remained at Saint Peter’s

University Hospital through October 2016, aside from two hospital stays at

CHOP for cardiac surgery in May and July 2016. After being discharged, D.J.

resided with his mother and Nieves, who were his primary caregivers.

In February 2017, D.J. -- 11 months old at the time -- had three episodes

of seizure-like behavior over the course of two weeks. During the first

episode, Nieves was home alone with D.J. and was changing his diaper when

D.J. went limp and passed out. Nieves attempted to revive D.J. by blowing in

his mouth, and he called D.J.’s mother and 9-1-1. By the time paramedics

arrived, D.J. was alert. The parents took D.J. to the pediatrician to follow up

and he was diagnosed with acid reflux. A few days later, the second seizure

episode occurred. While Nieves was changing D.J.’s diaper, the child passed

out and went limp again. Nieves applied oxygen with a nasal cannula, a

device that delivers supplementary oxygen to someone in need of respiratory

6

The facts in this section are derived from D.J.’s medical records and

testimony elicited at the Frye hearing.

27

assistance. The third episode began several days later. Nieves picked up D.J.

to change his diaper and D.J. went stiff and his jaw locked. Nieves brought

D.J. upstairs to his mother, and they called an ambulance. She took a video of

D.J. that showed him not responding to stimulation, with one arm stiff and the

other flexed, and eyes deviated to the left. The ambulance transported D.J. to

Saint Peter’s where he was admitted.

Those events triggered a child abuse investigation. Dr. Gladibel

Medina, a child abuse pediatrician and the medical director at the Dorothy B.

Hersh Regional Child Protection Center at Saint Peter’s, prepared a report after

reviewing D.J.’s medical history and interviewing Nieves and D.J.’s mother.

While at the hospital, medical staff discovered that D.J. had bilateral retinal

hemorrhages -- described as extensive, too numerous to count, involving

multiple layers of the retina and extending to the periphery -- and bilateral

subdural bleeding with both new and old blood present. Dr. Medina noted in

her report that D.J. “had a detailed review of his neonatal course and

comprehensive medical workup and follow-up by pediatricians and pediatric

subspecialists,” which included doctors with expertise in neurology, genetics,

hematology, neuroradiology, and pediatric ophthalmology, as well as a retinal

specialist.

28

That comprehensive medical evaluation did not reveal any pathology to

account for D.J.’s bilateral subdural bleeds, extensive bilateral retinal

hemorrhages, or neurological symptoms observed in early February 2017. Dr.

Medina noted in her report that D.J. did not sustain any reported accidental

injuries in February 2017. Thus, based on D.J.’s history and symptoms when

he was admitted, Dr. Medina diagnosed D.J. with SBS/AHT, with or without

impact, “within a reasonable degree of medical certainty.”

In the wake of Dr. Medina’s diagnosis, on June 30, 2017, a Middlesex

County grand jury indicted Nieves, charging him with second-degree

aggravated assault and second-degree endangering the welfare of a child.

Judge Pedro J. Jimenez, Jr., presided over the matter.

2. The Frye Hearing

In July 2018, Nieves moved before the trial court for a Frye hearing to

challenge the scientific reliability of the SBS/AHT hypothesis and to preclude

Dr. Medina’s SBS/AHT testimony at trial. Nieves argued that SBS/AHT was

no longer accepted in the scientific community. The court initially granted

Nieves’s request for a Frye hearing. Thereafter, the State filed a motion for

reconsideration. Based in part on Judge Benjamin S. Bucca, Jr.’s denial of a

Frye hearing in State v. Cifelli, which we discuss later, the court granted the

State’s motion and reversed its prior order, effectively denying Nieves a Frye

29

hearing. The Appellate Division granted Nieves’s motion for leave to appeal

and remanded for a Frye hearing. Judge Jimenez conducted that hearing over

the course of five days.

The State presented one witness, Dr. Medina. Nieves presented three

expert witnesses: (1) Dr. Joseph Scheller, who testified as an expert in the

fields of pediatric neurology and neuroimaging; (2) Dr. Julie Mack, who

testified as an expert in the fields of radiology and pediatric radiology; and (3)

Dr. Chris Alan Van Ee, who testified as an expert in biomechanics.

Additionally, the parties introduced into evidence and discussed numerous

scientific studies and articles during the hearing.

a. Dr. Gladibel Medina

According to Dr. Medina, the evaluation of a child when SBS/AHT is

suspected involves consultation with specialists including geneticists,

hematologists, radiologists, and ophthalmologists to determine whether there is

a possible disease, medical issue, or pathology that might be contributing to

the child’s symptoms. Dr. Medina testified that such specialists work together

to provide child abuse pediatricians with a full history of the child’s health.

Dr. Medina testified that the SBS/AHT diagnosis is widely accepted within the

medical community and accepted by all the pediatric subspecialties involving

intracranial injury. On cross-examination, Dr. Medina agreed that there are no

30

specific diagnostic criteria to define SBS/AHT; there are only symptoms a

child may exhibit when doctors are looking to see whether to diagnose

SBS/AHT.

Dr. Medina testified about the history and origins of SBS/AHT. Dr.

Medina stated that “the field of abusive head trauma or the recognition of

inflicted head injury in medicine is about 160 years” old. Dr. Medina

discussed medical literature from the mid-19th century that identified injuries

in children believed to be “associated with maltreatment by care givers.” Dr.

Medina then noted that approximately 80 years later, Dr. Guthkelch identified

subdural hematomas in children with no external signs of trauma -- which was

strongly associated with physical abuse. She further testified that in the 1970s,

Dr. Caffey began using terminology that referred to inflicted trauma in infants

caused by shaking-type injury.

Dr. Medina also testified about the study Dr. Ommaya conducted in

1968. She explained that “what we know about shaking, and the established

thresholds for intracranial injury comes from that study” and that “everything

else in biomechanics is based on those injury thresholds” from that study. Dr.

Medina stated that the validity of SBS/AHT as a diagnosis has not changed in

the medical community but has been challenged in terms of the mechanism of

shaking as the cause of injury in the scientific community studying

31

biomechanics. She submitted that the controversy about SBS/AHT in

biomechanics is focused on whether shaking can cause the forces needed to

generate intracranial injury in infants.

Regarding other biomechanical studies inspired by Dr. Ommaya, Dr.

Medina acknowledged that Dr. Duhaime’s study found that shaking alone did

not generate enough rotational forces but shaking with impact did. Dr. Medina

agreed that, since Dr. Duhaime’s 1987 study, there is debate about whether

shaking alone can reach the force that would cause retinal hemorrhages and

subdural hematomas. Dr. Medina explained that the Duhaime study was

confirmed by Dr. Michael T. Prange, 7 who, in 2003, used a different wooden

mass body-type surrogate to conclude that the threshold for intracranial injury

by shaking must produce force like that involved in a short (or higher) distance

fall, and that one could not reach the minimum established threshold by

shaking alone.

Regarding biomechanics, when defense counsel asked, “when we talk

about biomechanics, your opinion is based on acceleration and deceleration of

a baby,” Dr. Medina answered affirmatively, and added “[o]f the baby’s head.”

When asked whether she could explain acceleration and deceleration forces

7

Michael T. Prange et al., Anthropomorphic Simulations of Falls, Shakes, and

Inflicted Impacts in Infants, 99 J. Neurosurgery 143 (2003).

32

beyond her answer that “[i]t’s just movement of the head in different planes

inside the intracranial cavity,” Dr. Medina stated that she could not.

Dr. Medina further testified about two 2016 studies -- one conducted by

Carole A. Jenny 8 and another conducted by C.Z. Cory 9 -- that used different

models and changed the pattern of the shaking. Dr. Medina testified that the

researchers varied the biomechanics of the dolls, which allowed for chin-to-

chest impact and impact between the very back of the skull and the back. Dr.

Medina noted that those studies, which as she testified included shaking with

some impact, “actually surpassed the injury thresholds produced by the

original Ommaya study.”

When asked about studies conducted by Dr. John W. Finnie, in which

anesthetized lambs were shaken, Dr. Medina agreed that all the lambs had

spinal injuries and two out of seven in the first study had retinal hemorrhages.

In Finnie’s 2010 and 2012 studies, the lambs were vigorously shaken 10 times

for 30 seconds over the course of 30 minutes without head impact to determine

what injuries would occur with shaking alone. J.W. Finnie et al.,

8

Carole A. Jenny et al., Biomechanical Response of the Infant Head to

Shaking: An Experimental Investigation, 34 J. Neurotrauma 1579 (2017).

9

C.Z. Cory & M.D. Jones, Can Shaking Alone Cause Fatal Brain Injury? A

Biomechanical Assessment of the Duhaime Shaken Baby Syndrome Model, 43

Med. Sci. L. 317 (2003).

33

Neuropathological Changes in a Lamb Model of Non-accidental Head Injury

(the Shaken Baby Syndrome), 19 J. Clinical Neurosci. 1159 (2012); John W.

Finnie et al., Diffuse Neuronal Perikaryal Amyloid Precursor Protein

Immunoreactivity in an Ovine Model of Non-accidental Head Injury (the

Shaken Baby Syndrome), 17 J. Clinical Neurosci. 237 (2010). The 2010 study

noted that a “small subdural haemorrhage was found in two shaken lambs” out

of the seven lambs tested, and “retinal haemorrhages were minimal and only

seen in two” lambs. Finnie et al., 17 J. Clinical Neurosci. at 239. In the 2012

Finnie study that used nine lambs of varying weights, the study noted that

three of the nine lambs, the lower-weight lambs, died before the six-hour mark

at which the researchers planned to kill and then study the lambs. Finnie et al.,

19 J. Clinical Neurosci. at 1160. Although the 2012 study mentions that

“retinal damage” was found in the shaken lambs, “retinal hemorrhages” were

not specifically noted as they were in the 2010 study, and in 2012 the authors

stated that “no [retinal] haemorrhage was found in the serial histological

sections of the retina.” Id. at 1159, 1162-64. Dr. Finnie’s 2012 study further

34

noted observed injury to the brainstem 10 and craniocervical junction. 11 Id. at

1159, 1161. Although the authors of Finnie’s 2012 study concluded that

shaking alone resulted in the death of the three lower-weight lambs and that

the lack of evidence of impact does not negate the occurrence of non-

accidental head injury if the head is impacted on a soft surface, the authors

nevertheless advised that a “diagnosis of [non-accidental head injury] should

be concluded with caution, unless there is other corroborating evidence of

abuse or a convincing admission by the perpetrator.” 12 Id. at 1164.

10

The brainstem is “[t]he part of the brain that is connected to the spinal cord.

The brain stem is in the lowest part of the brain (just above the back of the

neck) and is made up of the midbrain, pons, and medulla oblongata.” Nat’l

Cancer Inst., Brain Stem, https://www.cancer.gov/publications/dictionaries/

cancer-terms/def/brain-stem (last visited Oct. 30, 2025).

11

“The craniocervical junction forms the bridge between the skull and the

spine, a highly mobile group of joints that allows the mobility of the head in

every direction. [It] plays a major role in protecting the inferior brainstem and

spinal cord.” Juliette Raoul-Duval et al., Geometric Growth of the Normal

Human Craniocervical Junction from 0 to 18 Years Old, 245 J. Anatomy 842

(2024) (parentheticals omitted).

12

Finnie’s lamb studies suffer from the same limitations of other studies in

attempting to replicate an infant model. Finnie himself recently acknowledged

the difficulties in the use of animal and mechanical models in noting that

“[d]ue largely to irreconcilable anatomic species differences between animal

brains and human infants, and a lack of resemblance of the shaking induced by

mechanical devices to real-world human neurotrauma, no animal model has

been able to reliably reproduce the full range of neuropathologic AHT

changes.” John W. Finnie & Peter C. Blumbergs, Animal Models of Pediatric

Abusive Head Trauma, 38 Child’s Nervous Sys. 2317 (2022). Finnie further

35

Dr. Medina also discussed benign enlargement of the subarachnoid space

(BESS). She described BESS as a medical diagnosis that puts infants at an

increased risk for subdural trauma, which she described as trauma to the

bridging veins that come from the brain to the dura (the sinus drainage). Dr.

Medina explained that BESS is associated with trauma to the bridging veins

with minimal movement involved, which causes subdural bleeding,

predisposes the infant to trauma, and is called benign because it does not cause

outward signs of trauma. Dr. Medina stated that to differentiate between

BESS and SBS/AHT, doctors must look at the whole clinical picture and

should never make a diagnosis of SBS/AHT based on one finding.

Dr. Medina noted that doctors rely on the “triad” of symptoms to flag

concern for SBS/AHT and to conduct further investigation. She stated that the

triad of symptoms presents as the following: (1) subdural hemorrhages

(bleeding in the brain); (2) severe retinal hemorrhages (bleeding in the

retina/eye); and (3) any neurological presentation known as encephalopathy,

which presents as unresponsiveness, apnea, seizures, or altered mental states.

stated that “it is unlikely that any animal model will be able to precisely

replicate the complete range of brain and ocular lesions to support a diagnosis

of AHT in human infants.” Id. at 2322.

36

She explained that there are different types of subdural hemorrhages

based on the cause of the hemorrhage. Most of the time, she stated, subdural

hemorrhages are caused by trauma; among young children, the most common

trauma is birth, and birth-related subdural hemorrhages usually resolve four to

six weeks after birth.

Dr. Medina testified that subdural hematomas can be associated with

retinal hemorrhages and stated that those observed in inflicted injury cases

have a distinct pattern that differs from hemorrhages caused by disease, illness,

or accidental trauma aside from motor vehicle roll-overs or other certain

medical conditions. She testified that when subdural hematomas coexist or are

identified in a child with severe retinal hemorrhages -- meaning hemorrhages

that are multilayered and too numerous to count -- it raises even more of a

concern for SBS/AHT.

According to Dr. Medina, if the symptoms of the triad remain

unexplained after a thorough review, then medical literature confirms the

symptoms “to be more specific for inflicted head injury.” Dr. Medina testified

that the SBS/AHT diagnosis thus requires an elimination of other possible

causes of the infant’s symptoms. Dr. Medina stated that the diagnosis is a

multidisciplinary process and noted that the diagnostic process and diagnosis

37

itself are well-established and widely accepted in the medical community, and

are reliable.

Regarding D.J., the child in Nieves, Dr. Medina testified that she

evaluated him on February 15, 2017, five days after he was admitted to Saint

Peter’s. Dr. Medina stated that after D.J. arrived at the hospital, doctors

evaluated him, looking for any other potential abnormalities. D.J. had an

ophthalmological examination that revealed severe multilayered retinal

hemorrhages in both eyes. Following that examination, the hospital contacted

the Division of Child Protection and Permanency (DCPP), and enlisted the

assistance of the Dorothy B. Hersh Child Protection Center in its evaluation of

D.J. Dr. Medina explained that a neuroradiologist diagnosed D.J. with

subdural bleeds and a pediatric ophthalmologist diagnosed him with severe

retinal hemorrhages, which the ophthalmologist documented was “consistent

with nonaccidental trauma.”

Dr. Medina confirmed that after obtaining the findings of the

subspecialists, she met with D.J.’s parents, who explained that between

February 3 and February 10, 2017, D.J. experienced three different episodes

while Nieves was the primary caregiver. Noting that D.J. had heart defects,

Dr. Medina described D.J.’s birth history as very complicated because he was

born extremely premature. She testified that D.J. had mild retinopathy, or

38

abnormally growing blood vessels, in the back of his eye when he was born,

but he was reevaluated at six months and was found to have healthy mature

retinas without any abnormalities. Regarding his altered mental state, Dr.

Medina noted that D.J. was a healthy baby and that there were no concerns in

terms of seizure-like activity until the events in February 2017. On cross-

examination, however, Dr. Medina conceded that when a baby is born at 25

weeks as D.J. was, there would be medical problems present at birth. She

further stated that although the cause is unknown, male premature babies are

especially prone to subdural hematomas at birth and that “there are problems

that can present months later.”

Dr. Medina found that D.J., then 11 months old, was developmentally

delayed, was at the developmental stage of a three or four-month-old infant,

and was starting to roll over but could not do much else. Though D.J. was able

to babble and smile, he did not have good head control and had decreased

muscle tone for his age, which, Dr. Medina explained, is not unusual when it

comes to children born as prematurely as D.J.

Dr. Medina stated that D.J.’s parents denied any history of accidental

trauma. Both parents mentioned that D.J.’s half-brother had been jumping in

the crib with him the month prior, a few days before the first incident, but the

parents reported that D.J. was smiling at the time and did not appear injured.

39

Dr. Medina stated that she diagnosed D.J. with “abusive head trauma

through shaking” within a reasonable degree of medical certainty. Dr. Medina

testified that she reached that diagnosis because D.J. presented to the hospital

with “altered mental status, subdural hemorrhages, and retinal hemorrhages in

the pattern that is severe and usually associated with very specific

circumstances,” but did not have evidence of hyperacute increase in

intracranial pressure, an aneurysm, or potential accidental trauma. Dr. Medina

testified that D.J.’s symptoms were not accounted for by a metabolic disorder

or accident; and every other possible explanation was ruled out by the treating

providers.

Regarding her report, in which she wrote that the tearing of the bridging

vein in D.J.’s brain caused his subdural hematomas, Dr. Medina conceded that

no studies show a relation between tearing of a bridging vein and subdural

hematomas. 13 Dr. Medina further testified that she made an assumption in

coming to that conclusion. Dr. Medina confirmed that her physical

13

The dissent appears to argue that Dr. Medina’s concession that she is

unaware of any studies that show a relation between the tearing of the bridging

vein and subdural hematomas is of no consequence and cites the Consensus

Statement to support that argument. Post at ___ (slip op. at 11 n.3.) To the

contrary, the fact that the State’s expert witness is unaware of purportedly

well-documented information regarding a factor considered in the medical

diagnosis she made in this case supports the unreliability of her testimony,

particularly since Dr. Medina wrote in her report that D.J.’s subdural

hematoma was caused by the tearing of the bridging vein.

40

examination of D.J. did not reveal any bruises on his arms, neck, or rib cage,

or any spinal injuries. Although Dr. Medina’s report stated a diagnosis of

“abusive head trauma, as it occurs with a shaking event with or without

impact,” during her testimony on cross-examination, Dr. Medina agreed that

“with impact” would mean “D.J. was shaken and hit against something,” and

Dr. Medina confirmed that there was no indication that D.J.’s head hit against

anything. 14

The trial court also asked Dr. Medina some clarifying questions.

[The court]: These diagnoses that you make to

conclude [SBS/AHT], you used the word probabilities.

Is that really all they’re pretty much based on? An

elimination of factors, and what’s left is a probable

result?

[Dr. Medina]: Elimination of things that can account

for the findings.

....

[The court]: [W]e can agree that we’re talking about

possibilities, or probabilities[?]

[Dr. Medina]: Yes.

[The court]: Not anything certain[], okay? And you

reached these probabilities and possibilities by way of

process of elimination[?]

14

Dr. Medina later testified in response to questions from the trial court that

D.J. did not “have any external signs of impact.”

41

[Dr. Medina]: And what’s been documented in the

literature.

In further response to the trial judge’s questions, Dr. Medina explained

that there was no way to specifically test for the exact cause of D.J.’s retinal

hemorrhages. However, she stated that the patterns of retinal hemorrhages he

presented are known to be associated with inflicted and traumatic injuries, and

that the cases involving confessions confirmed this. The court then asked,

“even the literature reaches all conclusions by way of process of elimination,

right? Based on testing done?” Dr. Medina answered, “[b]ased on what is

seen with accidents and not.” The court asked Dr. Medina whether “the best

[she] can do is say that there was some kind of inflicted trauma?,” to which she

responded “yes.”

b. Dr. Joseph Scheller

Dr. Joseph Scheller is a pediatric neurologist currently employed in

private practice who testified for the defense. Dr. Scheller noted that he has

been involved with studying and reviewing SBS/AHT for approximately 20

years and that he is aware of the modern debate about SBS/AHT.

Regarding biomechanics, Dr. Scheller noted that biomechanical studies

are ways to measure forces. He stated that the first biomechanical study of

shaking alone was conducted by Dr. Duhaime in 1987. He stated that Dr.

42

Duhaime’s experiment could not create forces inside the head that were

powerful enough to create a subdural hematoma. On cross-examination, Dr.

Scheller agreed that Dr. Duhaime’s ultimate conclusion was only that

SBS/AHT in its most severe acute form, meaning fatality, could not usually be

caused by shaking alone. Dr. Scheller further testified that there have not been

any subsequent biomechanical studies that have been able to produce the

amount of force needed to cause a baby to suffer a subdural hematoma with

shaking alone. Dr. Scheller acknowledged that he did not know what happens

when an adult shakes an infant six-months or younger but noted that he was

sure that violent shaking is “not a good thing.” Dr. Scheller further noted that

nobody knows for sure what happens because there have been no reports of

witnessed shaking where the result was subdural hematomas, retinal

hemorrhages, or neck injury. 15 He explained that for almost any other disease

15

In their briefing, both the State and the defense cite to a study involving

witnessed shaking that was published after Dr. Scheller testified at the Frye

hearing. See Kenneth W. Feldman et al., Abusive Head Trauma Follows

Witnessed Infant Shaking, 31 Child Abuse Rev., 2022, at 1, 1. The State

argues that the Feldman study supports the theory that shaking alone causes

the symptoms associated with SBS/AHT. The defense argues that the study’s

results do not support that proposition given the small percentage of children

studied that experienced symptoms associated with SBS/AHT and the

limitations of the study. In the Feldman study, researchers examined 23 cases

of witnessed shaking without impact and described 10 in greater detail. Id. at

3. Of those 23 cases, five children experienced subdural hemorrhages, retinal

hemorrhages, and neurological symptoms; another five experienced

43

or medical problem, there is quite good scientific data, but for SBS/AHT, the

scientific data is sorely lacking.

Regarding confessions, Dr. Scheller contrasted confessions, which he

characterized as unreliable due to coercion and inaccuracies, and medical

history, freely provided by a patient or caregiver to a doctor when asked why

they are seeing a doctor.

In terms of specific symptoms and their relationship to SBS/AHT, Dr.

Scheller explained that although subdural hematomas and retinal hemorrhages

can be symptoms of SBS/AHT, a child can be diagnosed with SBS/AHT

absent those symptoms. Further, he noted that the same was true of seizures,

bruising, broken ribs or bones, neck injuries, or other external signs of trauma.

Dr. Scheller then described the report he wrote regarding D.J. He stated

that he reviewed D.J.’s birth and nursery records, pediatric visits, his Saint

Peter’s hospitalization in 2017, and all of the radiology images -- X-rays,

neurological symptoms but no subdural or retinal hemorrhaging. Id. at 3-6.

Of the five children that experienced the three symptoms associated with

SBS/AHT, two had other signs of abuse, including multiple femur and tibia

fractures as well as healing rib fractures. Id. at 6. The study noted that

“[a]lthough shaking is rarely witnessed, these cases support that shaking alone

can cause typical AHT injuries.” Id. at 1. The authors, however, identified

limitations of the study in noting that “[w]itness statements might be

inaccurate or modified by self-interest. Problems with witness observations,

recollection and completeness of their statements could hamper some results.”

Id. at 8.

44

ultrasound scans, CAT scans, and MRI scans. In his report, Dr. Scheller

constructed a timeline of what happened medically to D.J. and concluded that

there was no evidence at all that D.J. was a victim of abuse.

Dr. Scheller then testified about D.J.’s MRI images taken in February

2017. In certain images he pointed out what he described as a subdural

hygroma, which is fluid that collects in the space between the brain and the

skull that the body does not know how to get rid of. He testified that a

subdural hygroma is caused by a minor trauma. He noted that subdural

hygromas are a common finding in children born prematurely.

Dr. Scheller stated that he believed D.J.’s subdural hygroma was caused

by his prematurity. He reminded the trial court that D.J. was born extremely

prematurely and weighed only 600 grams (approximately 1.3 pounds) at birth.

He explained that sometimes there can be no symptoms associated with

hygromas and at other times there can be poor feeding and poor weight gain

because there is pressure from that fluid on the brain, which causes irritation

and can cause seizures and sometimes delays in development.

Dr. Scheller explained that a bridging vein is a big vein usually found

near the top of the brain that collects blood and brings it back to the larger

blood vessels that deliver it to the heart. He stated that if a bridging vein

ruptured, it would cause a large blood clot. Dr. Scheller testified that a blood

45

clot found in D.J.’s MRI was not large and was just a sliver of a blood clot.

Furthermore, he believed D.J. had a subdural hygroma and that he had a

seizure on or around February 10 that certainly could have been caused by the

large fluid collection that was irritating his brain. He explained that such a

fluid collection could cause neurological symptoms because it squeezes the

brain a little and the brain can become irritated.

Defense counsel asked Dr. Scheller about what conditions were known

to cause retinal hemorrhages, to which he replied that the number one

condition in the world that causes them is “being born normal.” He explained

that one-fifth to one-third of perfectly normal babies in the nursery have retinal

hemorrhages. He then testified regarding a study performed by Dr. Natalia

Callaway 16 on retinal and optic nerve hemorrhages in newborn infants in 2016.

He explained that in the study, researchers looked at more than 200 perfectly

normal newborns shortly after they were born to examine their eyes and

determine if they had retinal hemorrhages. He stated that researchers found

that 20 percent had retinal hemorrhages and that out of that 20 percent, about

70 percent had multilayer retinal hemorrhages. Dr. Scheller further expressed

on cross-examination that pediatric ophthalmologists are experts in describing,

16

Natalia F. Calloway et al., Retinal and Optic Nerve Hemorrhages in the

Newborn Infant: One-Year Results of the Newborn Eye Screen Test Study,

123 Ophthalmology 1043 (2016).

46

detailing, and making sure that retinal hemorrhages do not affect the vision

and can perform surgery, if needed, to repair the eye, but they are not experts

in determining the cause of retinal hemorrhages.

Dr. Scheller testified that babies develop retinal hemorrhages at birth

because their heads are squeezed during the birthing process, creating

circulation problems in the brain, and because of the dramatic change from

fetal circulation to normal circulation. Dr. Scheller opined that he believed

D.J.’s retinal hemorrhages were caused by an accumulation of too much fluid

and too much pressure in between the brain and the inside of his skull. He

explained that children who are abused often have indicia such as fractured

bones, neck injury, bruises, or internal organ injuries, but D.J. did not. He

stated that he believed D.J. has another condition, hygroma, that mimics

SBS/AHT that Dr. Medina did not consider. Dr. Scheller noted that nowhere

in Dr. Medina’s report did she rule out chronic hygroma as a diagnosis. Dr.

Scheller also said that he did not rule out SBS/AHT in D.J.’s case, but he

noted that there are no specific criteria in the diagnosis of SBS/AHT, and that

there were very few findings consistent with an SBS/AHT diagnosis in D.J.’s

case. Dr. Scheller confirmed that in his medical opinion, to a reasonable

degree of scientific certainty, D.J. was not the victim of SBS/AHT.

47

On redirect, defense counsel asked Dr. Scheller one question: whether

there was “a study that shows a human can shake a baby causing the triad of

injuries,” to which Dr. Scheller responded that “[t]here is not.”

c. Dr. Julie Mack

Dr. Julie Mack, M.D., an assistant professor of radiology at the Penn

State College of Medicine at the Penn State Milton S. Hershey Medical Center

in Hershey, Pennsylvania, was qualified as an expert in the field of radiology

and pediatric radiology.

Dr. Mack testified about subdural collections around the brain and stated

that such collections can occur without trauma and without predisposing

conditions. Dr. Mack stated that the term subdural is used to refer to anything

that disrupts the connection between the arachnoid and the dura -- it can be

fluid, old blood, new blood, or a combination of blood plus fluid. She

explained that sometimes subdural hemorrhage is used as a catch-all phrase.

Next, Dr. Mack explained that BESS is an anatomic variation that is

poorly understood and occurs when there is more fluid than is typically seen

around the brain -- sometimes in the subarachnoid space, sometimes in the

subdural space. She stated that some infants who have BESS may have

seizures, or changes in the eyes such as a downward gaze and lethargy. Dr.

Mack further noted that it is unknown how many patients have BESS but do

48

not present with symptoms. Dr. Mack agreed with counsel that an infant could

present with BESS subdural collections with very little trauma. Dr. Mack

explained that it is not understood why some infants get BESS and others do

not, or why it is more common in males. She stated that BESS is sometimes

associated with a large head and is more common in premature infants.

Dr. Mack also described a network of blood vessels and cells in certain

areas of the brain, called the plexus, which can bleed without trauma. She

testified that it is not known why the dural plexus can bleed without trauma,

and that doctors do not even understand why those vessels are there.

Dr. Mack testified that confirmatory tests are critically important

because doctors cannot perform experiments, and that there is no confirmatory

test for SBS/AHT. She stated that the lack of a confirmatory test affects the

accuracy of the scientific literature, and that the literature on SBS/AHT is

flawed because of a built-in confirmatory bias. She discounted data in the

literature interpreted to show a 96 percent accuracy rate of retinal hemorrhages

in diagnosed SBS/AHT cases.

Regarding D.J., Dr. Mack testified that there were no signs of trauma in

D.J.’s scans: no soft tissue swelling, no skull fracture, and no abnormality

within the brain itself. She described the importance of D.J.’s medical history

as showing the subarachnoid space slowly expanding over time. She further

49

explained her opinion that D.J. had benign external hydrocephalus (BEH) --

subdural fluid collections in the context of enlarged subarachnoid spaces --

which are typically diagnosed only after children present with symptoms that

often include seizures, lethargy or sleepiness, or not eating well.

In discussing D.J.’s retinal hemorrhages, Dr. Mack testified that retinal

hemorrhages have been associated with BEH, sometimes being severe. Dr.

Mack stated that if a pediatrician showed her scans like D.J.’s and claimed that

retinal hemorrhages meant abuse, she would caution that the other relevant

data -- no brain injury, enlarging subarachnoid space over time, and fluid

collection -- cannot be ignored. She explained that assigning a label of abuse

in a case like this one would be a circular argument that ignores the data on the

imaging and sequence of films.

With regard to D.J.’s imaging, Dr. Mack explained that she would have

called the emergency room to say that he had subdural hemorrhages and asked

about any history to understand why. She further stated that it was appropriate

that D.J.’s initial evaluation phase was reported as a potential abuse case. She

agreed on cross-examination that shaking is dangerous and said that it could

particularly cause injuries to the neck. Regarding D.J.’s February 13, 2017

image, Dr. Mack explained that she could not tell whether what occurred there

was accidental or inflicted. She testified that there has not been good evidence

50

that shaking can cause bridging vein rupture, although there has been literature

that presumes that it does.

On cross-examination, Dr. Mack agreed that she had never conducted a

child abuse evaluation and that radiologists do not treat patients. In discussing

BESS, the State contended that the scans prior to February 13, 2017, were

normal. Dr. Mack disagreed, stating that the subarachnoid space slowly

enlarged over time, so she would not call the scans normal, but they could

reasonably be characterized as what can be seen among infants, and that the

scans reflected BESS, a finding that was left untreated.

Dr. Mack testified that the premise that shaking alone could cause the

injuries described in Dr. Medina’s report was a heated controversy and that she

did not think a finding of SBS/AHT could be made based on D.J.’s images.

d. Dr. Chris Alan Van Ee

Dr. Chris Alan Van Ee, an engineer who focuses on impact

biomechanics and mechanical engineering, defined biomechanics as the

application of mechanical principles to biological structures. He explained

that impact biomechanics looks at the human body from a mechanical

perspective to try to understand what forces or accelerations give rise to injury.

51

He testified that the forensic aspect involves looking at whether an injury

could be identified as trauma and what acts could have produced it.

In discussing angular acceleration, Dr. Van Ee stated that angular

acceleration -- which is how quickly the spin of something changes, here, the

spin of the head -- could give rise to things like subdural hematoma or

intracranial hemorrhage, i.e., hemorrhage inside of the skull around the brain.

Dr. Van Ee explained that, for example, if a merry-go-round stopped abruptly,

how quickly the stop occurred would be angular acceleration. He testified that

the faster the stop occurs, the greater the angular acceleration, and the slower

the stop occurs, the slower the angular acceleration.

Dr. Van Ee testified about how SBS/AHT relates to biomechanics. He

stated that SBS/AHT is a hypothesis whereby if someone holds a child by the

torso and shakes the child, the child’s head would go back and forth, creating

“angular accelerations of the head that are sufficient to rip bridging veins and

cause injury to a child.” Dr. Van Ee explained that if a biomechanics analysis

were conducted, it would determine what those angular accelerations are and

whether those angular accelerations are consistent or inconsistent with what

we know causes injury in a car crash or in a fall. When asked whether

biomechanics provides a way to test the hypothesis of shaking, he answered

that science can be used to test it, but there is no perfect test.

52

Dr. Van Ee explained the distinction between a whiplash event and a

shaking event, stating that Dr. Ommaya’s 1968 study used a sled that

“accelerate[d] th[e] chair with the primate in it at speeds representative of a

30-mile-per-hour crash” -- which was a whiplash event. He explained that in

some whiplash events, for example if someone sitting at a red light was rear-

ended by a vehicle traveling at five miles per hour, he could look at the head

acceleration and compare it to a shaking event. He continued that in a low-

speed incident like that, the accelerations could be five to 10 g, which does not

compare to a 30-mile-per-hour crash. Dr. Van Ee noted that subdural

hematomas in a five to 10 g whiplash event are typically not present, although

he noted that there is always an exception to the rule, specifically if someone

is particularly vulnerable. He provided the example of riding a roller coaster

and explained that some people have developed subdural hematomas due to

roller coasters, but that it was very rare that someone would suffer a traumatic

injury from those types of exposures.

Dr. Van Ee testified that the hypothesis that shaking alone can result in

damage to the bridging vein without simultaneously injuring the neck or torso

cannot be scientifically supported. He stated that because the neck is very

weak and vulnerable to injury, the first place to look for injury after a shaking

motion, from a biomechanics standpoint, is the neck. He further noted that the

53

idea that a subdural hemorrhage could be caused by ripping a bridging vein

without injuring the neck is unsupported by the data because the angular

accelerations that are created in shaking are less than what is seen in even a

one-foot fall.

Dr. Van Ee testified that if a baby fell over and hit their head on the

carpet, such a fall would not be associated with a subdural hemorrhage or a

massive traumatic brain injury, and that the angular accelerations of such a fall

that have been measured and published are greater than what is seen in

shaking. He explained that the data that exists in biomechanics shows that if

someone shakes a child, the neck should be where injuries would start, and the

levels of angular acceleration are well below the levels associated with head

injury. Thus, he testified that it is not known whether the triad of symptoms

and injuries can be produced by shaking alone, but neck injuries can be.

Addressing the Prange study published in the Journal of Neurosurgery,

Dr. Van Ee stated that the authors developed a crash-test device that

represented the weight and relative size of a six-week-old infant. He stated

that researchers shook the test device, slammed it onto a piece of foam that

represented a crib mattress, dropped it on the floor or the crib mattress from

varying heights (one foot, three feet, and five feet), and slammed it against a

wooden bench and also against a wooden bench with carpet on it. Dr. Van Ee

54

testified that the authors were trying to understand the head acceleration in

each setting.

Dr. Van Ee explained the findings of the study, noting that the one-foot

fall onto the floor gave rise to greater angular acceleration than acceleration

resulting from shaking. He explained that the authors of the Prange study

wrote that there was no data to indicate that shaking alone can give rise to the

injuries associated with SBS/AHT. Defense counsel asked how those findings

would change if an infant was larger, and Dr. Van Ee replied that the heavier

the child is, the harder the child is to shake, so less overall head acceleration,

angular velocity, and angular acceleration would be created.

Dr. Van Ee testified that the evidence is weak that shaking alone can

actually cause the injuries associated with SBS/AHT. However, he explained

that studies have shown that impact can cause those injuries. He stated that

there are studies where children have died as a result of abuse and the

autopsies reveal signs of impact that include subtle skull fracture or bleeding,

bleeding of the scalp, swelling of the scalp, or other injuries.

Dr. Van Ee stated that he has not seen a biomechanical study that

definitively concluded that shaking can cause the injuries associated with

SBS/AHT. He stated that there has been no study conducted with dummies or

animals that proved that subdural hematomas and retinal hemorrhages can be

55

caused by shaking alone. However, he acknowledged that there are confession

articles in which people have confessed to shaking a child and the child had

the injuries associated with SBS/AHT.

On cross-examination, Dr. Van Ee conceded that he is not a medical

doctor, does not have any medical degrees, has not diagnosed or treated

patients, has not been taught what a forensic examination for child abuse

entails, has never been trained in diagnosing SBS/AHT, has never conducted

an examination for abuse or been consulted when an examination for abuse

occurred, and has never examined an infant before.

Dr. Van Ee explained that as of now “there is not a mechanistic

explanation that allows one to go from shaking to those injuries” that makes

sense. In discussing Dr. Duhaime’s study, Dr. Van Ee noted that

approximately 15 children had died, and some had been thought to have been

killed by shaking alone, but examiners who performed autopsies found

evidence of impact in each child who died, so it was clear that the deaths did

not result from shaking alone. Moreover, he testified that in the Duhaime

study, football players shook a device that represented a one-month-old, and

the accelerations measured were very low and below the level of what

researchers thought would cause injury. Dr. Van Ee further explained that if

someone violently shakes an infant, that action is going to cause serious injury

56

and maybe even death, but the question at issue is would the shaking result in

the triad of symptoms at issue here and nothing else.

3. Trial Court Opinion

Following the hearing, on January 7, 2022, the trial judge issued a 75-

page written decision and accompanying order granting Nieves’s motion and

barring Dr. Medina’s expert testimony regarding SBS/AHT at trial.

The trial court concluded that SBS/AHT evidence was not reliable. The

court explained that the diagnosis of SBS/AHT and the triad of symptoms

associated with it are subject matters outside of the knowledge of the average

juror, which “necessarily requires expert testimony to explain how an AHT

diagnosis could be concluded without actual evidence of child abuse.” The

trial court ruled that it was clear from the literature and testimony that

SBS/AHT “has never been medically [or] scientifically validated as a

diagnosis because it has never been developed through scientific/medical

techniques or procedures which, in turn, would make it a diagnosis that is

scientifically or medically reliable.”

The trial court further explained that the evidence presented, especially

through the testimony of Dr. Medina, showed that SBS/AHT “is more

conjecture than a diagnosis because it is an option embraced once a

diagnostician runs out of diagnostic options.” The court underscored that there

57

was no test cited by Dr. Medina or referenced in the literature that could

support a finding that humans can produce the physical force necessary to

cause the symptoms associated with SBS/AHT in an infant. It further noted

that the State did not provide any evidence that Nieves inflicted any trauma

upon D.J. and determined that SBS/AHT was a flawed diagnosis because it

originates from a theory based upon speculation and extrapolation instead of

being anchored in facts developed through reliable testing.

The trial court stated that the literature and testimony showed that

SBS/AHT is an “assumption packaged as a medical diagnosis, unsupported by

any medical or scientific testing, based upon scaled down versions of testing

done on monkeys, wooden dolls, or other anthropomorphic surrogates.” The

court noted that this assumption has been proffered in cases like this one as

proof beyond a reasonable doubt as to the cause of an infant’s injuries.

However, it found that there was no support to permit that type of proffer to

stand because there has been no study that has ever validated the hypothesis

that shaking a child can cause the triad of symptoms associated with

SBS/AHT. The trial court stated that when used in a criminal courtroom to

prove causation, SBS/AHT “can be highly prejudicial and far less probative

. . . when no one has ever tested the capacity of an individual to shake a baby

in an effort to cause the triad of symptoms defining” SBS/AHT.

58

The trial court observed that human babies are very different from the

monkeys, wooden dolls, or other anthropomorphic surrogates utilized in the

studies referenced and reviewed concerning the effects of force and impact.

The court held that because of that, and as noted in Dr. Medina’s testimony,

we do not know, and will likely never know, what minimum force is necessary

to cause subdural hematomas or the other triad of symptoms because the

studies all reached diverse conclusions and, moreover, relied on models that

cannot be deemed reliable mirrors of the infant brain.

The court explained that defendant’s right to a fair trial includes the

right to have only evidence that is sufficiently established as reliable under

State v. Harvey, 151 N.J. 117 (1997), and Frye presented to a jury. The court

noted that, on the strength of its name alone, SBS/AHT “evokes a sense of

horror that affects the sensibilities of any competent juror, compromising their

ability to follow the instructions of the court concerning the weighing of

evidence fairly and impartially,” but that there is no scientific technique or

procedure to confirm SBS/AHT as a reliable diagnosis.

The trial court concluded that accordingly, SBS/AHT “cannot become

part of a case unless coupled with physical evidence that an accused subjected

an infant-victim to some impact of physical trauma that would support holding

the accused criminally liable.” Without such accompanying physical evidence,

59

the court determined, SBS/AHT “remains exactly what it is . . . a final option

lacking a reliable diagnostic criteria masking as a diagnosis” and “a hypothesis

based upon extrapolation of data, coupled with a ‘process of elimination’

engaged in by diagnosticians in an effort to reach a ‘conclusive diagnosis’

which, in the end, cannot be treated medically.” The court explained the

danger of experts influencing jurors who hear the phrase “medical certainty”

coming from an expert as suggesting a high degree of value and reliability

concerning SBS/AHT as a proven diagnosis for causation.

Therefore, the court concluded that testimony concerning SBS/AHT

could not be permitted in this case because it is not reliable evidence and was

far more prejudicial than it was probative. The court explained that permitting

such testimony in this case would be “the perfect recipe for a conviction not

borne of a fair and unbiased decision-making process but, instead, one which

would compromise the integrity of this prosecution and our criminal justice

system.” The court determined that the State failed to provide evidence that

Nieves inflicted force upon D.J. resulting in injuries symptomatic of an

SBS/AHT diagnosis and failed to prove that the science behind SBS/AHT is

sufficiently reliable to be used to implicate Nieves in abusive conduct and hold

him criminally liable for causing D.J.’s injuries. Thus, the court granted

Nieves’s motion to bar the admissibility of testimony concerning SBS/AHT.

60

Based on its decision barring SBS/AHT testimony, the trial court granted

Nieves’s motion to dismiss the indictment on January 28, 2022. The court

held that “the State has insufficient evidence to prove causation in this case

given the suppression of the testimony concerning [SBS/AHT].”

B. State v. Cifelli

Respondent Michael Cifelli is the father of J.C., who was born

prematurely in November 2016. In late December 2016, when J.C. was 10

weeks old, Cifelli was caring for J.C. when he began to vomit excessively and

exhibit fatigue and fever symptoms. Cifelli brought J.C. to the pediatrician

and then ultimately to the hospital for treatment. J.C. was diagnosed with a

viral illness and discharged the same day. The parents were told to follow up

with the pediatrician and that J.C. might have a gastrointestinal illness. 17

In early January 2017, while Cifelli was again caring for J.C., J.C.

experienced seizure-like symptoms. J.C. was subsequently admitted to the

hospital. While in the hospital, J.C. appeared again to be suffering from

seizure-like symptoms, unaware of his surroundings, and not easily consolable.

At the hospital, doctors determined that J.C. had fluid and blood around his

17

J.C.’s medical records are not in the record on appeal. The facts in this

section are derived largely from Dr. Medina’s testimony at a hearing regarding

the DCPP proceedings in this matter, as well as the grand jury testimony.

61

brain and retinal hemorrhages in his left eye. Those findings triggered a child

abuse investigation against Cifelli.

During J.C.’s hospitalization, his symptoms included the following:

fluid around the brain that required surgery to drain; old and new brain bleeds;

intraretinal and submacular retinal hemorrhages, meaning blood in multiple

layers of his eyes; an apparent macular hole in his right eye, which was later

diagnosed as “foveal vitreoretinal traction” -- marked by the gel-like

substance, between the lens of the eye and the retina, pulling away from the

retina; and a sudden increase in head circumference. J.C. underwent testing at

the hospital. Dr. Medina reviewed his medical records and test results. Dr.

Medina diagnosed J.C. with SBS/AHT with or without impact because she

found “that there was no other medical diagnosis that could explain his

symptoms.”

On November 1, 2017, a Middlesex County grand jury indicted Cifelli

on charges of aggravated assault and endangering the welfare of a child.

Shortly thereafter, DCPP filed a Title 9 complaint against Cifelli, alleging that

he caused J.C. to be an abused or neglected child. DCPP also filed an order to

show cause seeking care and supervision of J.C. The complaint was dismissed

62

in August 2017, and Cifelli moved to dismiss the indictment. 18 The trial court

denied the motion.

On December 31, 2018, Cifelli moved for a Frye hearing to determine

the admissibility of Dr. Medina’s testimony regarding SBS/AHT, arguing that

a diagnosis of SBS/AHT is scientifically unreliable. Judge Bucca denied

Cifelli’s motion, finding that SBS/AHT was generally accepted by the

scientific community and was therefore reliable.

After the Appellate Division granted Nieves’s motion for leave to appeal

and remanded the matter for a Frye hearing, Cifelli moved for reconsideration

of the denial in his case. Judge Bucca did not issue a written order, but the

parties agreed to hold the matter in abeyance pending the outcome of the Frye

hearing in the Nieves matter.

After the Frye hearing and Judge Jimenez’s ruling barring expert

SBS/AHT testimony in Nieves, Cifelli moved to dismiss his indictment,

claiming the parties agreed to be bound by the Frye ruling in Nieves. The

State opposed Cifelli’s motion, arguing that while it agreed to await the

outcome of the Frye ruling, it never agreed to be bound by the ruling.

18

Subsequently, on October 20, 2021, a second indictment was returned

against Cifelli and J.C.’s mother, charging them with additional acts of child

endangerment against both J.C. and his sibling. That indictment is not the

subject of this appeal.

63

Judge Bucca determined that both sides had agreed to be bound by the

ruling in Nieves. Pursuant to that agreement, Judge Bucca adopted Judge

Jimenez’s Frye ruling in Nieves and barred Dr. Medina’s testimony regarding

SBS/AHT in Cifelli’s case. Judge Bucca, however, did not dismiss the

indictment against Cifelli.

C. Consolidated Appellate Division Decision

The State moved for leave to appeal in both Nieves and Cifelli, arguing

that it had established SBS/AHT’s acceptance in the medical community and

that trial judges therefore should not have barred its proposed expert

testimony. State v. Nieves, 476 N.J. Super. 609, 617 (App. Div. 2023). The

State also appealed the trial court’s order barring testimony in Cifelli, arguing

that it did not agree to be bound by the Nieves decision and that the Nieves

decision was incorrect. Ibid. The Appellate Division granted leave to appeal

in both matters, consolidated the appeals, and affirmed both trial court

decisions. Id. at 617-18.

The Appellate Division held that “[t]he evidence supports the finding

that there is a real dispute in the larger medical and scientific community about

the validity of shaking only SBS/AHT theory, despite its seeming acceptance

in the pediatric medical community.” Ibid. The appellate court determined

that the experts who testified at the Frye hearing all agreed that “there was

64

controversy surrounding the theory that the biomechanical principles

underlying SBS/AHT actually supported the conclusion that shaking only can

cause the injuries associated with SBS/AHT.” Id. at 618. Further, the court

held that “[w]here the underlying theory integrates multiple scientific

disciplines, as here, the proponent must establish cross-disciplinary validation

to establish reliability,” which the State failed to do. Ibid.

The Appellate Division noted that there is a dearth of recent New Jersey

cases challenging the admissibility of SBS/AHT testimony. Id. at 649. The

court addressed several out-of-state SBS/AHT cases cited by the State, id. at

649-50, as well as the cases Nieves advanced, id. at 650-51. It noted that none

of the cases cited by Nieves and only a limited number of the State’s cases

expressly determined the admissibility of SBS/AHT evidence under Frye, and

that others determined its admissibility under a different standard, or did not

actually decide the question of the admissibility of SBS/AHT as a theory. Id.

at 649-51. The court explained that although some of the cases cited by the

State confirmed the reliability of SBS/AHT based on a prior court’s acceptance

of SBS/AHT, a reliance on such cases would be “a type of circularity that is

inappropriate given Nieves’s position that the medical and scientific

community’s view about SBS/AHT has evolved over time, warranting a new

review of the issue.” Id. at 651.

65

The court determined that SBS/AHT is a multidisciplinary diagnosis,

and the question of whether it is accepted within the medical and scientific

community “requires evaluation of two considerations: (1) whether the theory

is generally accepted by the biomechanical community and supported by

biomechanical testing; and (2) whether the theory is generally accepted by the

pediatric medical community and supported by the clinical data connecting the

constellation of symptoms with SBS/AHT.” Id. at 652.

The court held that the State “demonstrated general acceptance in the

pediatric community,” but it agreed with the trial court that “the State [did] not

demonstrate[] general acceptance of the SBS/AHT hypothesis to justify its

admission in a criminal trial.” Ibid. To the contrary, the court found the

evidence showed that there was “no general acceptance from the

biomechanical community, and [that] biomechanical testing has never proven

the premise of SBS/AHT, despite the hypothesis being grounded in

biomechanical principles.” Id. at 652-53. Accordingly, the court affirmed the

trial court’s decision precluding SBS/AHT testimony at trial. Id. at 654.

The court next addressed the State’s challenge to the trial court’s

dismissal of Nieves’s indictment. Ibid. The court determined that “without

SBS/AHT testimony, there was insufficient evidence to support the indictment

against Nieves” because the State would not be able to prove the element of

66

causation under either the aggravated assault or endangering the welfare of a

child charges. Id. at 655. The court explained that “[a]lthough the State could

present testimony that D.J. was in Nieves’s care when D.J. had his episodes of

limpness” and “was found to have retinal hemorrhages and subdural

hematomas, the State would not be able to explain how Nieves harmed D.J.,

leaving the question for the jury to determine.” Ibid. The court noted that “a

jury may draw a reasonable inference from the facts presented” but reasoned

that permitting the State to rely on jury inference here would impermissibly

“shift or lighten the burden of proof, or become a bootstrap to reduce the

State’s burden of establishing the essential elements of the offense charged

beyond a reasonable doubt.” Ibid. (quoting State v. Brown, 80 N.J. 587, 592

(1979)). The court explained that speculation cannot be disguised as a rational

inference and that “[r]equiring the jury to infer that Nieves harmed D.J. would

require the jury to make such a leap.” Ibid.

As to the Cifelli appeal, the court explained that because its decision

resolved the admissibility of SBS/AHT testimony under Frye, and must be

given conclusive weight, the decision of the trial judge in Cifelli to defer to the

trial court’s Frye ruling in Nieves was moot. Id. at 657.

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D. Review and Amicus Participation Granted

This Court granted the State’s petition for certification in Nieves and

motion for leave to appeal in Cifelli. 256 N.J. 451 (2024).

Additionally, we granted the applications of the following individuals

and entities to participate as amici curiae: the Attorney General of New Jersey

and DCPP (jointly); the Public Defender of New Jersey, Office of Parental

Representation; the Innocence Network and Center for Integrity in Forensic

Sciences (jointly); a group of Medical Doctors writing in support of

respondents; 19 a group of biomechanical engineers; 20 a group of scholars

whose work addresses cognitive bias; 21 the Family Justice Resource Center,

upEND Movement, MJCF Coalition, and Mothers Outreach Network

(collectively); the American Academy of Pediatrics, collectively with seven

19

Dr. Jacob Andersson, Prof. Anders Eriksson, Dr. John Galaznik, Dr. Patrick

Hamel, Dr. Ulf Högberg, Dr. Lawrence Hutchins, Dr. Charles J. Hyman, Prof.

Niels Lynøe, Dr. Marvin Miller, Dr. David Ramsay, Dr. Cyrille Rossant, Dr.

Robert K. Rothfeder, Dr. Irene Scheimberg, Dr. Joseph Scheller, Dr.

Guillaume Sébire, Dr. Waney Squier, Dr. Dale Vaslow, Dr. Knut Wester, and

Dr. R.K. Wright.

20

Lindsay “Dutch” Johnson, Ph.D.; Ken Monson, Ph.D.; Kirk Thibault, Ph.D.,

D-IBFES; Keith Button, Ph.D., PE; and Johan Ivarsson, Ph.D.

21

Dr. Jeff Kukucka, Ph.D.; Keith A. Findley, Esq.; Dr. Deborah Davis, Ph.D.;

and Dan Simon, Esq.

68

additional medical societies; 22 a group of law and psychology professors who

have studied false confessions; 23 and the Association of Criminal Defense

Lawyers of New Jersey (ACDL).

IV. PARTIES’ ARGUMENTS

A. State of New Jersey and Amici Supporting the State’s Position

The State argues that Dr. Medina’s diagnosis of D.J. was sufficiently

reliable to be the subject of expert testimony under N.J.R.E. 702 and should

have been admitted.

The State submits that it established SBS/AHT’s general acceptance in

the medical community, which is the relevant scientific community under

Frye. Accordingly, it contends that controversy in the field of biomechanics

does not justify the exclusion of a medical expert’s testimony on SBS/AHT.

The State submits that the Appellate Division erred in requiring general

acceptance within both the pediatric medical community and the

22

New Jersey State Chapter of the American Academy of Pediatrics;

American Association for Pediatric Ophthalmology and Strabismus; American

Society of Pediatric Neurosurgeons; American Society of Pediatric

Neuroradiology; American Professional Society on the Abuse of Children;

Society for Pediatric Radiology; and The Ray E. Helfer Society.

23

Dr. Richard A. Leo, Ph.D., J.D.; Dr. Hayley Cleary, M.P.P., Ph.D.; Dr. Kyle

Scherr, Ph.D.; Dr. Lucy Guarnera, Ph.D.; Dr. Saul Kassin, Ph.D.; Dr. Lindsay

Malloy, Ph.D.; Dr. Christian Meissner, Ph.D.; Dr. Allison Redlich, Ph.D.; and

Dr. Melissa Russano, Ph.D.

69

biomechanical community because biomechanics is not of equal importance to

pediatric medicine regarding the diagnosis of SBS/AHT and because Dr.

Medina’s diagnosis took relevant biomechanical research into account. The

State submits that “the lack of general consensus on [SBS/]AHT in the

biomechanical community is a result of biomechanical engineers’ inability to

replicate in a laboratory a phenomenon that clinicians have repeatedly

observed in the real world.” The State asserts that “[t]he fact that there exists

some disagreement among biomechanical engineers generally regarding

shaking alone as a mechanism of [SBS/AHT] should not render a diagnosis of

[SBS/AHT] unreliable in a particular case” because “absolute scientific

certainty is not the standard for the admissibility of expert testimony.” The

State further submits that biomechanical studies have failed to disprove that

shaking alone can cause the intracranial injuries associated with SBS/AHT.

Moreover, the State argues that it established SBS/AHT’s general

acceptance in the medical community through the expert testimony of Dr.

Medina, by offering authoritative scientific writings that establish the general

acceptance of the SBS/AHT diagnosis and its underlying methodology in the

medical community, and by offering numerous judicial opinions that have

accepted SBS/AHT as a reliable scientific premise.

70

Additionally, the State asserts that Dr. Medina did not opine that shaking

alone was the mechanism that caused D.J.’s injuries, but rather that D.J.

suffered from SBS/AHT “that occurs with a shaking event with or without

impact.” In the alternative, the State argues that the Court should remand

these matters to a Special Adjudicator to conduct a comprehensive evidentiary

hearing on the reliability of the SBS/AHT diagnosis under the standard

announced in Olenowski I.

Several amici support the State’s position. The New Jersey Attorney

General and DCPP argue that SBS/AHT is a generally accepted medical

diagnosis long recognized by a host of national and international medical

organizations. They maintain that the Appellate Division’s decision means the

State may lose the ability to prosecute certain cases of child endangerment and

the decision would also hamper DCPP’s ability to fulfill its Title 9

responsibilities. Amici echo the State’s argument that SBS/AHT satisfies the

general-acceptance standard based on the presented expert testimony,

scientific writings, and judicial opinions. They contend that biomechanics

does not cut in either direction or resolve the dispute in anyone’s favor because

it has not disproven the theory of SBS/AHT. They further argue that the

Appellate Division’s reliance on State v. Pickett, 466 N.J. Super. 270 (App.

Div. 2021), to support a finding of the need to consider more than one

71

scientific community is misplaced because it did not establish a bright-line

rule.

The American Academy of Pediatrics and its joint participants

(collectively, AAP) argue that the relevant scientific community for the

diagnosis of abusive head trauma is the interdisciplinary specialties involved

in the actual clinical evaluation, diagnosis, and treatment of patients. The

AAP contends that SBS/AHT is a clinical medical diagnosis made by a

clinician based on the signs, symptoms, and history of the patient. The AAP

argues that because biomechanical engineers are not consulted as part of the

diagnostic process, biomechanical engineering is not its own relevant scientific

community regarding the clinical diagnosis of SBS/AHT. Moreover, the AAP

argues that the medical community does not recognize a genuine debate of the

validity of SBS/AHT.

B. Nieves and Cifelli and Amici Supporting Their Position

Respondent Nieves urges this Court to affirm the exclusion of expert

testimony about SBS/AHT without impact injuries because the State failed to

prove that the diagnosis is accepted within the relevant scientific communities

of biomechanics and medicine. He argues that the State was required to prove

the reliability of SBS/AHT (or SBS/AHT with no impact, and as

distinguishable from AHT generally), which it failed to do. He contends that

72

SBS/AHT covers a wide range of injuries and symptoms and does not employ

a specific diagnostic criterion; instead, doctors engage in a process of

elimination to determine whether there are other explanations for the

symptoms. Nieves submits that because SBS/AHT is a differential diagnosis

that integrates multiple scientific disciplines, a finding of reliability must

consider all fields used to render such a diagnosis. Nieves contends that

because it was the biomechanical understanding of angular acceleration that

led to the development of the SBS/AHT theory and the theory remains rooted

in biomechanical principles, the relevant scientific community for purposes of

a reliability analysis must include biomechanics.

Nieves argues that the State failed to prove that SBS/AHT is generally

accepted as reliable in the field of biomechanics. He asserts that the State

conceded and the record shows that SBS/AHT has never been validated in the

field of biomechanics because no study has shown that humans can shake a

child with enough force to cause the triad of symptoms associated with the

SBS/AHT diagnosis. Additionally, he submits that research has shown that

violent shaking would damage a child’s neck before causing the triad of

symptoms, which undermines the reliability of the SBS/AHT diagnosis.

Moreover, he contends that the State failed to prove that SBS/AHT is

generally accepted as reliable in the field of medicine because it did not prove

73

that there is a generally accepted and reliable medical basis to believe that

shaking can cause the triad without causing any other injuries. Instead, he

asserts, the “general acceptance” the State proffered in the medical community

relies on unsupported theories and unreliable confession studies. He also

contends that the State failed to prove that SBS/AHT is generally accepted as

reliable based on judicial authority.

Finally, Nieves argues that remand is unnecessary because appointing a

Special Adjudicator will not affect whether the reliability of SBS/AHT is

litigated in other cases, and an adequate record already exists because there

was a Frye hearing below.

Respondent Cifelli generally relies on the arguments made by Nieves

and contends that the judgments below should be affirmed. Cifelli also argues

that the State has not established any error in the trial court’s ruling and should

be barred by principles of judicial and equitable estoppel from challenging its

own prior position on appeal. He maintains that the trial court found that the

State agreed to be bound by the Nieves court’s Frye decision and that, to

protect the integrity of the judicial process, the State should be barred under

principles of estoppel from advocating a contrary position.

Several amici argue in support of respondents. The Office of the Public

Defender argues that SBS/AHT is a medicolegal diagnosis for a child’s

74

pathology rooted in the kind of speculation and conjecture that this Court has

long held to have no place in New Jersey’s child welfare jurisprudence as the

cause of harm or injury to a child.

The ACDL argues that admitting SBS/AHT diagnoses in criminal court

would lower New Jersey’s high standards for the reliability of evidence. The

ACDL contends that the biomechanical scientific community’s rejection of

SBS/AHT as a diagnosis undermines the reliability of the testimony at issue

here.

The biomechanical engineers argue that experts in biomechanics are

members of the relevant scientific community for determining the reliability of

SBS/AHT because the diagnosis is rooted in biomechanical principles

regarding the effects of rotational forces on the contents of the skull. They

explain that biomechanical expertise is necessary to answer the question of

whether it is even physically possible for a human adult to shake an infant in a

manner that can produce forces sufficient to cause the triad of symptoms. The

biomechanical engineers contend that the current state of biomechanical

research does not support the validity of an SBS/AHT-by-shaking diagnosis

because such research does not support the theory that shaking can cause the

triad of symptoms associated with an SBS/AHT diagnosis. The biomechanical

engineers maintain that, in light of those biomechanical findings and other

75

research, courts and medical professionals are increasingly skeptical of

SBS/AHT diagnoses.

The medical doctors supporting respondents argue that there is no

scientific basis for an SBS/AHT diagnosis. They contend that there are no

scientific or biomechanical studies that validate the hypothesis that abusive

shaking can cause the triad of symptoms; that every component of the triad has

numerous non-abusive causes; and that SBS/AHT is not a medical diagnosis.

They contend that the SBS/AHT hypothesis was adopted based on the

misapplication of animal studies and circular reasoning. They submit that the

shift to evidence-based medicine exposed the dearth of reliable literature

supporting the SBS/AHT hypothesis. The medical doctors argue that the

SBS/AHT hypothesis is not generally accepted in the relevant scientific

community, which includes biomechanical scientists.

The cognitive bias scholars argue that there are high error rates in

subjective medical determinations like SBS/AHT which are exacerbated by

cognitive bias. They maintain that context bias especially impacts SBS/AHT

determinations, as experimental studies clearly establish.

Family Justice Resource Center, upEND Movement, MJCF Coalition,

and Mothers Outreach Network argue that children and parents experience

serious long-term harm to their mental and physical health as a result of forced

76

separation -- which repeatedly occurs on the basis of unreliable scientific

evidence.

The Innocence Network and Center for Integrity in Forensic Sciences

(jointly, Innocence Network) argue that the trial and appellate courts properly

excluded the testimony regarding SBS/AHT by following the current scientific

understanding rather than outdated legal precedent. The Innocence Network

maintains that the current scientific consensus does not support diagnoses of

SBS/AHT based only on the triad of symptoms associated with shaking. The

Innocence Network argues that courts across the country are thus increasingly

recognizing that the SBS/AHT diagnosis is not supported by science. It

contends that recognition of the new scientific understanding of SBS/AHT has

led to numerous reversals and exonerations. The Innocence Network

maintains that forensic evidence is uniquely powerful in its ability to influence

and potentially mislead jurors and factfinders, and that the risk of admitting

flawed forensic evidence is not hypothetical, but the leading cause of wrongful

conviction.

The professors who study false confessions argue that the SBS/AHT

“confession studies” the State relies on fail to account for the well-documented

phenomenon of false confessions and improperly assume that the purported

confessions were true without independent corroboration.

77

V. LEGAL STANDARDS

A. Standard of Review

“Generally, appellate courts review a trial court’s determination of the

admissibility of evidence for an abuse of discretion.” Harvey, 151 N.J. at

166. However, “[w]hen reviewing a decision on the admission of scientific

evidence, an appellate court should scrutinize the record and independently

review the relevant authorities, including judicial opinions and scientific

literature.” Id. at 167. Additionally, “[w]hether expert testimony is

sufficiently reliable to be admissible under N.J.R.E. 702 is a legal question we

review de novo.” State v. J.L.G., 234 N.J. 265, 301 (2018).

B. Expert Testimony

N.J.R.E. 702 governs the admission of expert testimony. The rule

provides that “[i]f scientific . . . knowledge will assist the trier of fact to

understand the evidence or to determine a fact in issue, a witness qualified as

an expert by knowledge, skill, experience, training, or education may testify

thereto in the form of an opinion or otherwise.” N.J.R.E. 702. The proponent

of expert testimony must establish that “(1) the subject matter of the testimony

[is] ‘beyond the ken of the average juror’; (2) the field of inquiry ‘[is] at a state

of the art such that an expert’s testimony could be sufficiently reliable’; and

78

(3) ‘the witness [has] sufficient expertise to offer the’ testimony.” J.L.G., 234

N.J. at 280 (quoting State v. Kelly, 97 N.J. 178, 208 (1984)).

During the relevant period, New Jersey courts relied on the Frye

standard to assess the reliability prong. Ibid. The Frye standard requires trial

courts “to determine whether the science underlying the proposed expert

testimony has ‘gained general acceptance in the particular field in which it

belongs.’” Ibid. (quoting Frye, 293 F. at 1014). Notwithstanding the Frye

test’s emphasis on general acceptance in the relevant field(s), the science

underlying the expertise “must have a ‘sufficient scientific basis to produce

uniform and reasonably reliable results [that] will contribute materially to the

ascertainment of the truth.’” State v. Chun, 194 N.J. 54, 91 (2008) (quoting

State v. Hurd, 86 N.J. 525, 536 (1981)).

Reliability of the expert testimony is of paramount import, and “[i]n

evaluating the admissibility of scientific evidence introduced by the State in

criminal cases, it is important to recognize that a high degree of reliability is

necessary where the freedom, or even the life, of an individual is at stake.”

Biunno, Weissbard & Zegas, Current N.J. Rules of Evidence, cmt. 6.1 on

N.J.R.E. 702 (2025). “‘Proof of general acceptance within a scientific

community can be elusive,’ and ‘[s]atisfying the test involves more than

simply counting how many scientists accept the reliability of the proffered

79

[technique].’” State v. Cassidy, 235 N.J. 482, 492 (2018) (alterations in

original) (quoting Harvey, 151 N.J. at 171). Further, because labeling

evidence as “scientific” or “expert” creates a “clear” “danger of prejudice” --

i.e., the possibility that juries will “accord excessive weight to unreliable

expert testimony” simply because of its label, State v. Cavallo, 88 N.J. 508,

518 (1982) -- “[g]eneral acceptance ‘entails the strict application of the

scientific method, which requires an extraordinarily high level of proof based

on prolonged, controlled, consistent, and validated experience.’” Cassidy, 235

N.J. at 492 (quoting Harvey, 151 N.J. at 171).

The proponent of the expert evidence has the burden to “clearly

establish” general acceptance, Cassidy, 235 N.J. at 492; Chun, 194 N.J. at 92,

in one or more of three ways: “expert testimony, authoritative scientific and

legal writings, and judicial opinions,” J.L.G., 234 N.J. at 281; see also

Cassidy, 235 N.J. at 492. Courts, in turn, act as gatekeepers for ensuring the

reliability of expert testimony. J.L.G., 234 N.J. at 307-08; see also State v.

Sowell, 213 N.J. 89, 99-100 (2013).

A key step in a court’s gatekeeping function under Frye is to identify the

relevant scientific community. See Pickett, 466 N.J. Super. at 302.

Importantly, in certain circumstances, “there might be more than one scientific

community to consider.” Ibid. And, when there is more than one relevant

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scientific community to consider, the proponent of the expert evidence must

clearly establish general acceptance in all of the relevant scientific

communities involved. See ibid. Specifically, “cross-disciplinary validation”

may be required “to determine reliability” when validation by a single

scientific community is “too narrow” because there is another scientific

community or communities “to which [the evidence also] belongs.” Id. at 323.

Indeed, in this Court’s opinion in Olenowski II, we recognized that the

relevant scientific communities for determining the reliability of Drug

Recognition Expert (DRE) testimony included both medicine and toxicology.

State v. Olenowski (Olenowski II), 255 N.J. 529, 604 (2023).

This Court has on many occasions determined the admissibility of expert

testimony under Frye. Recently, in J.L.G., we revisited a previously accepted

theory as the science developed and determined that it no longer met the

reliability prong and was therefore inadmissible in criminal trials because it

was based on clinical practice and not supported by objectively tested

scientific evidence. 234 N.J. at 272, 291. There, the defendant challenged the

scientific reliability of expert testimony regarding Child Sexual Abuse

Accommodation Syndrome (CSAAS). Id. at 272. CSAAS is a diagnostic tool

comprised of five categories of behavior commonly demonstrated by child sex

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abuse victims: “secrecy; helplessness; entrapment and accommodation;

delayed, conflicted, unconvincing disclosure; and retraction.” Id. at 271.

Although we had previously found CSAAS expert testimony reliable in

1993, and it had been presented in child sexual abuse trials throughout the

country for over twenty years, we determined that “[b]ased on what is known

today, it is no longer possible to conclude that CSAAS has a sufficiently

reliable basis in science to be the subject of expert testimony.” Id. at 272. We

found significant disagreement among the scientific community on the issue of

false recantation because recantation rates varied among studies, and although

researchers agreed that recantation happens in a minority of cases, they

disagreed on the rate. Id. at 295-97. Additionally, we found denial was a

heavily debated topic and that the studies that found higher rates of denial

were of questionable validity. Id. at 297-99.

In applying the Frye standard, we held that “expert testimony about

CSAAS in general, and its component behaviors other than delayed disclosure,

may no longer be admitted at criminal trials.” Id. at 272. In so holding, we

acknowledged that “CSAAS stems from observations made in clinical practice

-- not systematic scientific study,” and that while “[c]linical wisdom is

valuable, . . . it must be examined with care and objectively tested.” Id. at 291

(emphases added). We determined that there was not general acceptance in the

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scientific community about either retraction or false denial. Id. at 302.

Additionally, we explained that “[t]o satisfy the reliability prong . . . it is not

enough to state that certain behaviors can be observed in some victims some of

the time -- or that those behaviors are not inconsistent with abuse” because

“[t]hat is not the type of ‘state of the art’ evidence the case law requires.” Id.

at 303 (quoting Kelly, 97 N.J. at 208).

C. Case Law Addressing SBS/AHT

As the Appellate Division noted, few New Jersey court opinions have

addressed the reliability of SBS/AHT, and none involve the reliability of

SBS/AHT in the context of shaking without impact. Two prior New Jersey

cases ruled on the admissibility of SBS/AHT in cases involving shaking with

impact: State v. Compton, 304 N.J. Super. 477 (App. Div. 1997), and State v.

Galloway, 133 N.J. 631 (1993).

In Compton, a defendant’s four-and-one-half-month-old son died in his

care, and the defendant was charged with murder. 304 N.J. Super. at 479, 481.

While in custody, the defendant told his wife that he had thrown the infant in

the air, and the infant went through his hands and fell. Id. at 482. The

defendant then shook the infant to try to revive him. Ibid. On appeal, the

defendant challenged, among other things, the general acceptance and

reliability of the SBS/AHT diagnosis. Id. at 483. The Appellate Division

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analyzed the testimony of the State’s expert, the medical research and

literature, and case law from other jurisdictions. Id. at 485-87. The court

determined that SBS/AHT evidence was admissible because the State’s expert

testified that the theory was generally accepted, the condition had been

adequately analyzed and recognized in medical research and literature, and

other jurisdictions had recognized the theory. Ibid. Moreover, the Appellate

Division noted that this Court, in Galloway, “recognized the condition

implicitly, by acknowledging expert testimony describing [SBS/AHT] in

connection with a particular case at bar, or treating it as an accepted medical

condition without further comment.” Id. at 486.

In Galloway, the defendant was convicted of the murder of his

girlfriend’s three-month-old son based on SBS/AHT evidence. 133 N.J. at

637. The defendant stated that he had picked up the baby, who was crying, but

fell while carrying him, causing the infant to cry more. Id. at 638. The

defendant admitted that he then shook the baby hard several times to stop the

crying. Ibid. The defendant challenged his conviction based on, among other

things, the trial court’s jury instruction regarding diminished capacity. Id. at

637. In describing the facts of the case, the opinion noted that the defendant’s

shaking of the infant “caused the child’s head to bob back and forth rapidly,

causing hemorrhaging of the blood vessels of the child’s brain, commonly

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known as the ‘shaken baby syndrome.’” Id. at 638. We reversed and

remanded based on the jury instruction and its interpretation of the child

endangerment statute. Id. at 649, 662. We did not analyze SBS/AHT or

mention it again in the opinion. See generally id. (including no analysis or

other mention of SBS/AHT).

Although New Jersey case law on SBS/AHT is sparse, many cases from

around the country in the past 15 years have focused on the reliability of

SBS/AHT. See Ex parte Roark, 707 S.W.3d 157, 185, 187-88 (Tex. Crim.

App. 2024) (granting the defendant’s application for a writ of habeas corpus,

vacating his conviction, and remanding for a new trial because scientific

knowledge regarding the State’s SBS/AHT theory of injury had evolved since

the time of trial, and the defendant likely would not have been convicted if

such newly evolved scientific evidence had been presented at trial); Smith v.

State, 882 S.E.2d 300, 302, 308-10, 312 (Ga. 2022) (vacating the trial court’s

order denying the defendant’s extraordinary motion for new trial and

remanding for an evidentiary hearing to determine whether the defendant’s

proposed expert testimony regarding developments in the understanding of the

triad of symptoms and the diagnosis of SBS/AHT constituted newly

discovered evidence); Allison v. State, 448 P.3d 266, 267-68, 271-74 (Alaska

Ct. App. 2019) (reversing the defendant’s conviction because the trial court

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erred in barring the defendant’s genetic medical testimony as a defense against

SBS/AHT allegations); Commonwealth v. Millien, 50 N.E.3d 808, 809-10

(Mass. 2016) (holding that the defendant was denied the right to effective

assistance of counsel because his attorney did not retain a medical expert when

the prosecution’s case rested almost entirely on medical expert testimony, and

noting that “[t]here is a heated debate in the medical community as to whether

a violent shaking of a baby alone can generate enough force to cause the triad

of symptoms of traumatic brain injury, and as to whether these symptoms can

sometimes be caused by a short accidental fall”); People v. Bailey, 41

N.Y.S.3d 625, 626-27 (App. Div. 2016) (affirming the trial court’s decision to

vacate the defendant’s conviction and grant a new trial because advancements

in science and medicine constituted newly discovered evidence calling into

question the validity of the SBS/AHT diagnosis); Del Prete v. Thompson, 10

F. Supp. 3d 907, 954, 957, 958 n.10 (N.D. Ill. 2014) (finding that the

defendant had carried her burden in petitioning for habeas relief, establishing

that no reasonable jury would find her guilty beyond a reasonable doubt

through new SBS/AHT testimony regarding the science of biomechanics and

the fact “that the evidence basis for the proposition that shaking alone can

cause injuries of the type at issue here is arguably non-scientific,” and noting

that “more recent developments in this area . . . arguably suggest[] that a claim

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of shaken baby syndrome is more an article of faith than a proposition of

science”); State v. Edmunds, 746 N.W.2d 590, 596-98 (Wis. Ct. App. 2008)

(reversing the denial of the defendant’s motion for a new trial on the basis that

“newly discovered evidence in this case shows that there has been a shift in

mainstream medical opinion since the time of [the defendant’s] trial as to the

causes of the types of trauma” that the deceased infant exhibited); Cavazos v.

Smith, 565 U.S. 1, 9, 13 (2011) (Ginsburg, J., dissenting) (dissenting from the

United States Supreme Court’s summary reversal and remand of the Ninth

Circuit’s grant of a habeas petition, despite the Court finding that the jury’s

verdict was supported by the record, in part because “[d]oubt has increased in

the medical community ‘over whether infants can be fatally injured through

shaking alone’” (quoting Edmunds, 746 N.W.2d at 596)).

The Michigan Supreme Court recently addressed the reliability of

SBS/AHT testimony in People v. Ackley, 870 N.W.2d 858, 859-60 (Mich.

2015). In that case, the court determined whether a defendant was denied

effective assistance of counsel when his trial counsel failed to secure an expert

witness to defend against SBS/AHT accusations. Ibid. The defendant was

convicted of first-degree murder and first-degree child abuse after a three-

year-old in his care died. Id. at 860. At trial, defense counsel reached out to

only one expert, a doctor, who “advised counsel . . . that he was ‘not the best

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person’ for the defense.” Ibid. The doctor stated that, for the purpose of

assisting the defense, he was on the wrong side of the “religion”-like divide

between doctors when it came to diagnosing SBS/AHT and injuries that result

from short falls, meaning he could not assist the defense. Id. at 860-61.

However, counsel did not contact or retain another expert and continued to

rely on that doctor in preparing for trial. Id. at 861. The court granted a new

trial, and the appellate court reversed that determination on appeal. Id. at 862.

The Michigan Supreme Court reversed the appellate court’s ruling. Id.

at 867. It determined that counsel’s efforts did not satisfy his duty to make

reasonable investigations, “especially in light of the prominent controversy

within the medical community regarding the reliability of SBS/AHT

diagnoses.” Id. at 864. It explained that counsel’s failure to secure an expert

to assist in the defense undermined the court’s confidence in the outcome of

the case because “in a SBS/AHT case . . . where there is ‘no victim who can

provide an account, no eyewitness, no corroborative physical evidence and no

apparent motive to kill,’ the expert ‘is the case.’” Id. at 867 (quoting Deborah

Tuerkheimer, The Next Innocence Project: Shaken Baby Syndrome and the

Criminal Courts, 87 Wash. U. L. Rev. 1, 27 (2009)). Thus, the Michigan

Supreme Court found that the failure of the defense counsel to even attempt to

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find a supportive expert was ineffective assistance that likely impacted the

case. Ibid.

More recently, the Michigan Supreme Court substantively explored the

admissibility of expert testimony and the controversy surrounding the

diagnosis of SBS/AHT in People v. Lemons, 22 N.W.3d. 42 (Mich. 2024). In

that case, the defendant was convicted of first-degree felony murder in 2005

for the death of an infant following an allegation of SBS/AHT. Id. at 48.

Subsequently, the defendant filed a motion for relief from judgment, “arguing

that new evidence undermined the prosecution’s theory that the child’s cause

of death was” SBS/AHT. Ibid. The trial court held evidentiary hearings and

determined that the defendant’s proposed biomechanical engineering expert

testimony was inadmissible under Michigan’s Daubert-like expert witness

testimony rule. Ibid.

The Michigan Supreme Court disagreed and stated that “the SBS[/AHT]

hypothesis is inherently ‘grounded in biomechanical principles.’” Id. at 55

(quoting Nieves, 476 N.J. Super. at 653). It held that the testimony by the

defendant’s biomechanical expert (Dr. Van Ee, who participated in the Frye

hearing in this matter) satisfied the rule and was thus admissible because he

“was a qualified expert in the field of biomechanical engineering”; “[h]is

testimony regarding the biomechanical mechanism of SBS[/AHT] would assist

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the trier of fact in ascertaining a fact at issue”; the field of “[b]iomechanical

engineering is a legitimate field of scientific study”; his “testimony was ‘based

on sufficient facts or data’ and was ‘the product of reliable principles and

methods’”; and he was able to apply those principles and methods reliably to

the facts of the case. Id. at 56, 57 (quoting Mich. R. Evid. 702).

Importantly, the Michigan Supreme Court acknowledged that “a segment

of the medical community takes significant issue with biomechanical research

on SBS[/AHT],” but it determined that, “just as a biomechanical engineer may

not testify about medical causation outside of their expertise, the medical

community is not the judge of the validity of biomechanical research, nor is it

the sole relevant expert community with respect to SBS[/AHT].” Id. at 59. It

found “the position that biomechanics -- the study of forces acting on and

generated within the human body -- is divorceable from a diagnosis of

[SBS/AHT] to be untenable.” Ibid.

There is, of course, also case law finding SBS/AHT evidence reliable

and therefore admissible at trial. See Clark v. State, 315 So. 3d 987, 993, 995,

996-97 (Miss. 2021) (holding that SBS/AHT expert testimony was reliable and

properly admitted); Nielsen v. State, 430 P.3d 740, 751 (Wyo. 2018) (noting

that the differential diagnosis used to diagnose SBS/AHT is a sufficiently

reliable methodology, and that the SBS/AHT experts in the case “properly

90

explained their diagnoses . . . and how they arrived at their conclusions.”);

Wolfe v. State, 509 S.W.3d 325, 327, 335, 341 (Tex. Crim. App. 2017)

(affirming defendant’s conviction and holding that SBS/AHT testimony was

properly admitted at trial because it was sufficiently reliable); People v.

Flores-Estrada, 51 N.Y.S.3d 863, 864-65 (Sup. Ct. 2017) (denying defendant’s

motions to preclude expert SBS/AHT testimony and for a Frye hearing

regarding SBS/AHT); People v. Thomas, 998 N.Y.S.2d 590, 592 (Cnty. Ct.

2014) (same); Futrell v. Commonwealth, 471 S.W.3d 258, 265, 281-86 (Ky.

2015) (reversing defendants’ convictions because the trial court abused its

discretion by refusing to remove, for cause, two unqualified jurors, but holding

that the trial court did not abuse its discretion in admitting SBS/AHT expert

testimony); Johnson v. State, 933 So. 2d 568, 570 (Fla. Dist. Ct. App. 2006)

(affirming defendant’s conviction and holding that the medical expert’s

SBS/AHT opinion was admissible, and that a Frye hearing was unnecessary).

VI. ANALYSIS

With those legal principles in mind, as well as the history of SBS/AHT

and the numerous studies and articles presented by both parties, we turn to

whether SBS/AHT expert testimony should be admitted in cases governed by

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the Frye standard in which defendants are charged with child abuse offenses as

a result of shaking without impact.

A. The Relevant Scientific Communities

We must first determine the relevant scientific community or

communities for purposes of SBS/AHT.

As Dr. Medina testified, the starting point in the evolution of SBS/AHT

was Dr. Ommaya’s 1968 whiplash study, which tested the acceleration and

deceleration of monkeys’ brains during a simulated rear-end car accident at 30

miles per hour. Drs. Guthkelch and Caffey later relied on Dr. Ommaya’s study

in conceptualizing SBS/AHT. Dr. Caffey’s conclusion that SBS/AHT, which

he called infant whiplash syndrome, could result from shaking a child was

based in part on Dr. Guthkelch’s paper, which, in turn, was based on Dr.

Ommaya’s study.

It is therefore evident that the foundation of SBS/AHT lies in

biomechanical science and engineering. The State and its supportive amici,

including the AAP, note that the biomechanical engineering community

informs the SBS/AHT inquiry but protest that biomechanical engineers are not

of significant relevance or are not a scientific community unto themselves.

Indeed, the State notes that “[SBS/]AHT is a clinical diagnosis that is informed

by research in biomechanics” but at the same time argues that the

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biomechanical community is “not of coequal importance” in the debate

regarding the reliability of SBS/AHT expert testimony. What’s more, the State

proffered no biomechanical expert testimony on its behalf.

It seems particularly odd, knowing that the origins of SBS/AHT lie

entirely in biomechanics, to relegate biomechanics to second-class status. It

cannot be that the scientific community upon which the very foundation of the

State’s SBS/AHT testimony is based is not as relevant to the theory’s

acceptance as the medical community that now diagnoses SBS/AHT -- a

diagnosis that quite possibly would not have existed if not for a biomechanical

study and the field of biomechanics in the first place.

Moreover, a scientific community is either relevant or not for purposes

of determining admissibility of scientific evidence at trial -- degrees of

relevance are not weighed, and for good reason. Were this Court to agree that

the biomechanical engineering community is a relevant community -- but not

that relevant -- the question would then arise regarding how much relevance

our courts are to afford to this relevant community. Would testimony from an

expert in an only “somewhat relevant” community be presented to a jury, with

the jury instructed to afford only 20 or 30 percent weight to that testimony?

That is not a workable procedure. As the Michigan Supreme Court noted in

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Lemons, it is simply untenable to divorce the diagnosis of SBS/AHT from its

origin, the study of biomechanics.

There can certainly be more than one relevant scientific community for

purposes of Frye. Again, in Olenowski II, we recognized that the relevant

scientific communities in determining the reliability of DRE testimony were

both the medical and toxicology communities. 253 N.J. at 604. Here, we find

that the relevant scientific communities for purposes of determining the

reliability of SBS/AHT expert testimony are both the medical/pediatric

community and the biomechanical engineering community.

B. Application of the Frye Standard of Reliability

We now turn to whether, under the Frye standard of reliability, the State

has met its burden of establishing that Dr. Medina’s expert testimony

regarding SBS/AHT without impact is sufficiently reliable for admission at

trial. The State, as the proponent of the expert evidence, has the burden to

“clearly establish” general acceptance in the relevant scientific communities

through expert testimony, authoritative scientific and legal writings, and

judicial opinions. See J.L.G., 234 N.J. at 281; Cassidy, 235 N.J. at 492. Based

on the testimony, evidence, and scientific studies and writings, this Court finds

that the State has not met that burden. We find that the State has not shown

general acceptance within the biomechanical community regarding whether

94

shaking without impact can produce the “triad” of symptoms associated with

SBS/AHT: subdural hematomas, multilayered retinal hemorrhages, and

encephalopathy.

We address the State’s argument that the Appellate Division

misunderstood Dr. Medina’s diagnosis and improperly focused its opinion on

shaking without impact. Specifically, the State argues that Dr. Medina

diagnosed D.J. with SBS/AHT “as it occurs with a shaking event with or

without impact.” Although, the State is correct that Dr. Medina noted that

diagnosis in her records, she testified on cross-examination that there was no

indication that D.J.’s head hit against anything and that D.J. did not “have any

external signs of impact.” Therefore, it is evident from Dr. Medina’s own

testimony that she did not observe any signs of any impact, so Nieves’s case is

properly assessed as one involving shaking without signs of impact, as Dr.

Medina herself testified. Although doctors may use the phrase “shaking with

or without impact” as a catchall, those events are, as the studies and science

make clear, very different and should be treated as such.

Regarding the scientific foundation of SBS/AHT, Dr. Ommaya’s 1968

whiplash study concluded, as explained above, that brain injuries could result

from “rotational displacement of the head on the neck alone, without

significant direct head impact.” Ommaya, 204 J. Am. Med. Assoc. at 285. As

95

Dr. Medina herself testified, Dr. Ommaya’s study was later referenced as the

scientific and biomechanical basis for what eventually became known as

SBS/AHT. But Dr. Ommaya’s study had nothing to do with infants or the

understanding of what happens in the shaking of infants. His study focused on

recreating whiplash events in monkeys at speeds of 30 miles per hour that

mimicked rear-end car collisions. Drs. Guthkelch and Caffey used Dr.

Ommaya’s whiplash study to support their hypothesis that young children with

brain injuries were subject to abusive shaking.

Over three decades after he published his whiplash study, Dr. Ommaya

published a follow-up article questioning and challenging the scientific basis

of SBS/AHT and specifically noting that Drs. Guthkelch and Caffey failed to

factor into their theories the level of speed employed during his whiplash

study. More pointedly, Dr. Ommaya stated that the assumptions upon which

pediatric brain and retinal literature had been based in the past few decades --

assumptions based on his own study -- were “ambiguous or incorrect” and

were used in the differential diagnosis of SBS/AHT “usually without reference

to available biomechanical analysis.” Ommaya et al., 16 Brit. J. Neurosurgery

at 227.

Thus, Dr. Ommaya, whose 1968 study was the foundation of SBS/AHT

theory and diagnosis in the first instance, publicly disclaimed the validity of

96

SBS/AHT’s foundation. Further, he specifically noted that much of the

literature and study of SBS/AHT was made without reference to available

biomechanical analysis, a field of study that is imperative to understanding the

manner in which acceleration and deceleration forces occur within the body.

Indeed, even Dr. Caffey’s 1974 study, which is universally referenced

regarding the beginnings of SBS/AHT theory, concluded that the evidence at

the time was “manifestly incomplete and largely circumstantial.” Caffey, 54

Pediatrics at 403. And then Dr. Guthkelch, over 40 years after he published a

study advancing the theory of SBS/AHT, also questioned the scientific

foundation of that diagnosis. Guthkelch, 12 Hous. J. Health L. & Pol’y at 202-

04. Dr. Guthkelch further called for “civility in scientific discourse” because

he believed the controversy regarding SBS/AHT had risen to a level of

divisiveness that interfered with the commitment to pursuing the truth. Id. at

201.

Indeed, this debate regarding the scientific validity of SBS/AHT without

impact has been extraordinarily contentious. For example, the AAP and many

other medical organizations around the world adopted the Consensus

Statement, which employed the terms “denialists” and “denialism” to describe

those who have questioned the scientific basis for SBS/AHT, and noted that

“denialism of child abuse has become a significant medical, legal and public

97

health problem.” Choudhary et al., 48 Pediatric Radiology at 1050, 1059. The

charged language used in the discourse surrounding SBS/AHT on both sides is

disconcerting, given that the goal is, and should be, a search for truth and

understanding.

The record established in the Frye hearing regarding the challenges to

the science behind SBS/AHT in the matters before us does not deny the

existence of child abuse, but rather questions the scientific and biomechanical

underpinnings of the diagnosis of SBS/AHT as the sole basis for a legal

finding of child abuse. Indeed, even the experts who testified for the defense

at the Frye hearing acknowledged that shaking a young child could result in

injury. Dr. Scheller specifically

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