Commonwealth v. Mattis

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SJC-11693

COMMONWEALTH vs. SHELDON MATTIS.

Suffolk. February 6, 2023. - January 11, 2024.

Present: Budd, C.J., Gaziano, Lowy, Cypher, Kafker, Wendlandt,

& Georges, JJ.

Homicide. Constitutional Law, Sentence, Cruel and unusual

punishment, Parole. Parole. Practice, Criminal, Sentence,

Parole.

Indictments found and returned in the Superior Court

Department on December 21, 2011.

Following review by this court, 484 Mass. 742 (2020),

findings of fact and a ruling of law were issued by Robert L.

Ullmann, J.

Ryan M. Schiff (Paul R. Rudof & Ruth Greenberg also

present) for the defendant.

Cailin M. Campbell, Special Assistant District Attorney

(John C. Verner, Assistant District Attorney, also present) for

the Commonwealth.

The following submitted briefs for amici curiae:

Darina Shtrakhman, of California, Matt K. Nguyen, of the

District of Columbia, & Adam Gershenson for Jeffrey Aaron &

others.

Andrea Lewis Hartung, of Illinois, & Marsha L. Levick, of

Pennsylvania, & Oren Nimni for the Sentencing Project & others.

2

Jonathan W. Blodgett, District Attorney for the Eastern

District, & David F. O'Sullivan, Assistant District Attorney,

for District Attorney for the Eastern District & another.

Jasmine Gonzales Rose, of Oregon, Duke K. McCall, III, &

Douglas A. Hastings, of the District of Columbia, Robert S.

Chang, of Washington, Caitlin Glass, Neda Khoshkhoo, & Katharine

Naples-Mitchell for Boston University Center for Antiracist

Research & others.

Kenneth J. Parsigian, Avery E. Borreliz, Erin M. Haley, &

Martin W. Healy for Carol S. Ball & others.

Benjamin H. Keehn, Committee for Public Counsel Services, &

John J. Barter for Committee for Public Counsel Services.

BUDD, C.J. When it comes to determining whether a

punishment is constitutional under either the Eighth Amendment

to the United States Constitution or art. 26 of the

Massachusetts Declaration of Rights, youth matters. See, e.g.,

Miller v. Alabama, 567 U.S. 460 (2012); Graham v. Florida, 560

U.S. 48 (2010); Roper v. Simmons, 543 U.S. 551 (2005);

Diatchenko v. District Attorney for the Suffolk Dist., 466 Mass.

655 (2013) (Diatchenko I), S.C., 471 Mass. 12 (2015). In

Miller, supra at 465, 476, the United States Supreme Court

struck down mandatory life imprisonment without the possibility

of parole for juveniles based in part on the "mitigating

qualities of youth." Approximately one and one-half years

later, this court went further than Miller and concluded that

sentencing a juvenile to life without parole in any circumstance

would violate art. 26. See Diatchenko I, supra at 669-670.

The defendant, Sheldon Mattis, was convicted of murder in

the first degree, among other charges, and was sentenced to a

3

mandatory term of life in prison without the possibility of

parole, see G. L. c. 265, § 2 (a). Commonwealth v. Watt, 484

Mass. 742, 754-756 (2020). On appeal, he challenged the

constitutionality of his sentence as applied to him. He argued

that because he was eighteen years old at the time of the

murder, he is entitled to the same protection as juvenile

offenders (i.e., those from fourteen to seventeen years of age)

convicted of murder in the first degree, who receive a term of

life with the possibility of parole. See G. L. c. 265, § 2 (b).

Here, we consider whether our holding in Diatchenko I

should be extended to apply to emerging adults, that is, those

who were eighteen, nineteen, and twenty years of age when they

committed the crime.1 Based on precedent and contemporary

standards of decency2 in the Commonwealth and elsewhere, we

conclude that the answer is yes.3

1 For the purposes of this opinion, "emerging adult" is

defined as someone who is eighteen, nineteen, or twenty years of

age. Although the record contains some references to

individuals who are as old as twenty-four years of age as

"emerging adults," the focus of the record and the Superior

Court judge's factual findings, which guide our analysis today,

are limited to offenders who are aged eighteen, nineteen, or

twenty at the time of the crime.

2 As discussed infra, our understanding of contemporary

standards of decency is informed by the updated scientific

record.

3 We acknowledge the amicus briefs submitted by (1) twenty-

three retired Massachusetts judges, Boston Bar Association, and

Massachusetts Bar Association; (2) seventeen neuroscientists,

4

Background. 1. The homicide. The evidence presented in

the defendant's trial is summarized in Watt, 484 Mass. at 744-

745.4 We provide a condensed version of events as the jury could

have found them. On September 25, 2011, the defendant; his

codefendant, Nyasani Watt; and another friend observed Kimoni

Elliott standing outside a nearby convenience store. Id. at

744. The defendant approached Elliott on a bicycle and asked

him where he was from. Elliott replied, "Everton." Id. The

two then parted ways. Id.

Elliott met Jaivon Blake in a nearby parking lot while the

defendant returned to Watt and said, "[B]e easy, because that's

them kids." Watt, 484 Mass. at 744-745. A few minutes later,

when Elliott and Blake were in view, the defendant handed Watt a

gun and told Watt "to go handle that." Id. at 745. Watt rode

toward Elliott and Blake on a bicycle and shot them from behind.

Id. Elliott survived gunshot wounds to his neck and right arm,

psychologists, and criminal justice scholars; (3) Sentencing

Project, Juvenile Law Center, and Roderick and Solange MacArthur

Justice Center; (4) the Committee for Public Counsel Services;

(5) Boston University Center for Antiracist Research, Fred T.

Korematsu Center for Law and Equality, Center on Race,

Inequality, and the Law, and Criminal Justice Institute at

Harvard Law School; and (6) the district attorney for the

Eastern district and the district attorney for the Plymouth

district.

The defendant and Watt were tried together, and their

4

appeals were consolidated. The decision was published under

Watt's name.

5

but Blake died from a single gunshot wound to the torso. Id. at

744.

2. Procedural history and development of the record. In

2013, the defendant and Watt were tried jointly and convicted of

murder in the first degree on the theories of deliberate

premeditation and extreme atrocity or cruelty, among other

charges. Watt, who was seventeen at the time of the shooting,

received a life sentence with the possibility of parole after

fifteen years.5 Watt, 484 Mass. at 745. See G. L. c. 265, § 2

(b). See also G. L. c. 127, § 133A; G. L. c. 279, § 24. The

defendant, who had turned eighteen approximately eight months

prior to the crime, received a life sentence without the

possibility of parole. Watt, supra. See G. L. c. 265, § 2 (a).

See also G. L. c. 127, § 133A. Each defendant filed a motion

for a new trial. Among other things, the defendant argued that

his mandatory sentence of life without parole violated art. 26's

prohibition of cruel or unusual punishment because he was under

twenty-two years of age when he committed the murder. A

Sentencing in this case occurred after the United States

5

Supreme Court's decision in Miller, but mere days before we

issued our decision in Diatchenko I. Despite not yet having our

guidance on how to sentence such juveniles in the absence of new

legislation on the matter, the judge correctly sentenced Watt to

the equivalent penalty for murder in the second degree -- the

"next-most severe sentence under the sentencing statute"

available at the time for a juvenile convicted of murder in the

first degree. See Watt, 484 Mass. at 753.

6

Superior Court judge denied both motions, and the appeals from

these denials were consolidated with the defendants' direct

appeals. Watt, supra at 743-744.

We unanimously upheld the denial of both defendants'

postconviction motions and affirmed all convictions. Watt, 484

Mass. at 765. However, we remanded the defendant's case6 to the

Superior Court for "development of the record with regard to

research on brain development after the age of seventeen[,

which] will allow us to come to an informed decision as to the

constitutionality of sentencing young adults to life without the

possibility of parole." Id. at 756.

A Superior Court judge, who had also been the trial judge,

conducted three days of evidentiary hearings during which three

expert witnesses -- neuroscientist Dr. Adriana Galván, forensic

psychologist7 Dr. Robert Kinscherff, and forensic psychologist

Dr. Stephen Morse -- testified on the topic of adolescent

neurological and psychological development after the age of

seventeen.8 The defendant also entered in the record the

6 Because the art. 26 question did not apply to Watt, we

remanded only the defendant's case to the Superior Court. Watt,

484 Mass. at 765.

7 "[F]orensic psychology [i]s the use of psychological

theories and methods and data to help the legal system resolve

legal questions."

8 The parties agree that all of the experts who submitted

evidence in the record are duly qualified in the relevant fields

7

transcript of the testimony of a fourth expert witness,

developmental psychologist Dr. Laurence Steinberg.9 The

of neuroscience and forensic psychology, among other

specialties, and are recognized as leaders in their respective

professional fields.

Galván holds a Ph.D. in neuroscience and is a tenured

professor of psychology at the University of California, Los

Angeles (UCLA), as well as the director of UCLA's Developmental

Neuroscience Lab. She has coauthored over one hundred book

chapters and peer-reviewed studies, many of which have been

published in leading journals in her field. She has received

numerous honors and awards, including the Presidential Early

Career Award for Scientists and Engineers as well as the Troland

Award from the National Academy of Sciences.

Kinscherff holds both a juris doctor and a Ph.D. in

clinical psychology. He is a professor in the doctoral

psychology program at William James College. He has been

qualified as an expert in forensic psychology numerous times and

was formerly the Assistant Commissioner for Forensic Mental

Health at the Department of Mental Health.

Morse holds both a juris doctor and a Ph.D. in psychology

and social relations. He is a tenured professor of law and

professor of psychology and law at the University of

Pennsylvania. He has written numerous articles on neuroscience

and the law, many of which have been published in leading

journals on law and neuroscience. He has been qualified as an

expert in at least twenty cases and was previously the Legal

Director at the MacArthur Foundation's Law and Neuroscience

Project.

Galván and Kinscherff testified on behalf of the defendant.

Morse testified on behalf of the Commonwealth.

9 Steinberg holds a Ph.D. in human development and family

studies. He is a tenured professor at Temple University. Over

the course of forty years, he has authored scores of studies

that have been published in peer-reviewed journals, including

top journals in his field. He has been qualified as an expert

in developmental psychology approximately thirty times. His

research was cited in two of the leading Supreme Court cases on

the Eighth Amendment's ban on cruel and unusual punishment as

8

Commonwealth and the defendant also submitted voluminous

exhibits, including numerous scientific studies on adolescence

and neurobiological maturity.

The record was transmitted to us in May 2021 but did not

include factual findings. In December 2021, we again remanded

this case, along with the case underlying our decision in

Commonwealth v. Robinson, 493 Mass. (2023), to the Superior

Court for the development of factual findings based on the

previously transmitted record.10 Specifically, we requested

findings regarding "whether the imposition of a mandatory

sentence of life without the possibility of parole for . . .

those convicted of murder in the first degree who were eighteen

to twenty-one at the time of the crime, violates [art.] 26."

A different Superior Court judge issued factual findings in

July 2022, concluding that the mandatory imposition of a

sentence of life without parole for offenders who were eighteen,

applied to juveniles. See Miller, 567 U.S. at 471 (referencing

Steinberg & Scott, Less Guilty by Reason of Adolescence:

Developmental Immaturity, Diminished Responsibility, and the

Juvenile Death Penalty, 58 Am. Psychologist 1009, 1014 [2003]);

Roper, 543 U.S. at 569-573 (same). Steinberg testified on

behalf of the defendant in the case underlying our decision in

Commonwealth v. Robinson, 493 Mass. (2023), a case raising a

nearly identical sentencing claim. See note 10, infra.

10This case was paired with the one underlying Robinson,

493 Mass. , because, similarly to Mattis, Robinson asked this

court to consider whether a sentence of life without parole is

constitutional when applied to those who committed their crime

while under twenty-one years of age.

9

nineteen, or twenty years old at the time they committed the

crime is a violation of art. 26. In particular, the judge found

that emerging adults are "less able to control their impulses"

and that "their reactions in [emotionally arousing] situations

are more similar to those of [sixteen and seventeen year olds]

than they are to those [twenty-one to twenty-two] and older."

The case and its entire evidentiary record subsequently were

transmitted back to this court, where the defendant argued that

it is unconstitutional to sentence an emerging adult to life

without the possibility of parole in any circumstance, and the

Commonwealth argued that such a sentence is constitutional if

imposed after an individualized hearing.

Discussion. Adopted in 1780, art. 26 states: "No

magistrate or court of law, shall . . . inflict cruel or unusual

punishments." In evaluating the constitutionality of a

sentence, this court is guided by "[t]he fundamental imperative

of art. 26 that criminal punishment be proportionate to the

offender and the offense." Diatchenko I, 466 Mass. at 671. A

punishment is unconstitutional (i.e., cruel or unusual) if it is

so disproportionate to the crime that it "shocks the conscience

and offends fundamental notions of human dignity." Id. at 669,

quoting Cepulonis v. Commonwealth, 384 Mass. 495, 497 (1981).11

11Similarly, the Eighth Amendment's prohibition on cruel

and unusual punishment "flows from the basic 'precept of justice

10

1. Constitutional framework. To evaluate the

proportionality of a mandatory life sentence imposed on a

category of offenders (here, emerging adults), we look to

precedent as well as what contemporary standards of decency, as

defined by objective indicia, require. See Graham, 560 U.S. at

61, quoting Roper, 543 U.S. at 563-564 ("The Court first

considers 'objective indicia of society's standards, as

expressed in legislative enactments and state practice,' to

determine whether there is a national consensus against the

sentencing practice at issue. . . . [Then] guided by 'the

standards elaborated by controlling precedents and by the

Court's own understanding and interpretation of the Eighth

Amendment's text, history, meaning, and purpose,' . . . the

Court must determine . . . whether the punishment in question

violates the Constitution"); Roper, supra at 560-561.12 As for

that punishment for crime should be graduated and proportioned'

to both the offender and the offense." Miller, 567 U.S. at 469,

quoting Roper, 543 U.S. at 560.

12The dissent asserts that the "tripartite" test is the

proper tool to analyze the constitutionality of the sentence

here. Post at . See Commonwealth v. Jackson, 369 Mass. 904,

910-916 (1976). That test considers (1) the nature of the

offense and the offender in light of the degree of harm to

society, (2) the sentence imposed and penalties prescribed for

more serious crimes in Massachusetts, and (3) a comparison

between the sentence imposed with the penalties prescribed for

the same offense in other jurisdictions. It traditionally has

been used, both by this court and the Supreme Court, to assess

whether a term-of-years sentence is grossly disproportionate to

a given offense, considering all the circumstances of a

11

the latter, current scientific consensus regarding the

characteristics of the class can help determine the contemporary

standards of decency pertaining to that class. See Diatchenko

I, 466 Mass. at 659-661, 669-671. See also Miller, 567 U.S. at

471-472 ("Our decisions rested not only on common sense . . .

but on science and social science as well"); Graham, supra at

68; Roper, supra at 569-570; Commonwealth v. Okoro, 471 Mass.

particular case. Id. See, e.g., Commonwealth v. Sharma, 488

Mass. 85, 89-90 (2021); Commonwealth v. LaPlante, 482 Mass. 399,

403 (2019); Commonwealth v. Perez, 477 Mass. 677, 685-686

(2017), S.C., 480 Mass. 562 (2018); Opinions of the Justices,

378 Mass. 822, 824-825 (1979). See also Ewing v. California,

538 U.S. 11 (2003); Harmelin v. Michigan, 501 U.S. 957 (1991);

Solem v. Helm, 463 U.S. 277 (1983).

Although the tripartite test incorporates elements of the

approach we use today, it is of limited utility here. Its

"threshold comparison between the severity of the penalty and

the gravity of the crime does not advance the analysis" where

neither the sentence's proportionality to the charged offense

nor the existence of a more serious offense in the Commonwealth

is being challenged. See Graham, 560 U.S. at 61. Rather, our

cases show, and Supreme Court precedent affirms, that it is the

"categorical" framework, which focuses on contemporary standards

of decency, that applies here, where the task is to assess

whether a sentence is disproportionate when applied to an entire

category of offenders. See id. ("In cases turning on the

characteristics of the offender, the Court has adopted

categorical rules . . . [and] consider[ed] 'objective indicia of

society's standards'"); Diatchenko I, 466 Mass. at 669

(contemporary standards of decency render imposition of life

without parole sentence on particular category of offenders

unconstitutionally disproportionate). See also, e.g., Roper,

543 U.S. at 560-563 (standards of decency dictate death

penalty's unconstitutionality when imposed on those under

eighteen); Atkins v. Virginia, 536 U.S. 304, 321 (2002)

(standards of decency dictate death penalty's

unconstitutionality when imposed on those with intellectual

disabilities).

12

51, 60 (2015) ("the determination that youth are

constitutionally distinct from adults for sentencing purposes

has strong roots in recent developments in the fields of science

and social science").

a. Precedent. In a series of cases responding to

challenges to juvenile sentences, the Supreme Court has

consistently opined that the "mitigating qualities of youth"

must be taken into consideration when it comes to sentencing.

Johnson v. Texas, 509 U.S. 350, 367 (1993). See, e.g., Jones v.

Mississippi, 141 S. Ct. 1307, 1314 (2021), citing Miller, 567

U.S. at 476; Johnson, supra ("A sentencer in a capital case must

be allowed to consider the mitigating qualities of youth in the

course of its deliberations over the appropriate sentence").

For example, when striking down the death penalty for juveniles

in Roper, the Court discussed the "relevance of youth as a

mitigating factor" at length, concluding that "[o]nce the

diminished culpability of juveniles is recognized, it is evident

that the penological justifications for the death penalty apply

to them with lesser force than to adults." Roper, 543 U.S. at

570-571.

In Graham, 560 U.S. at 76, the Court noted that an

"offender's age is relevant to the Eighth Amendment, and

criminal procedure laws that fail to take defendants'

youthfulness into account at all would be flawed." The Court

13

concluded that it was unconstitutional to sentence juveniles who

did not commit homicide to life without parole because they lack

the maturity to be classified among the worst offenders

deserving of the harshest punishments. The Court further noted

that although "[m]aturity can lead to that considered reflection

which is the foundation for remorse, renewal, and rehabilitation

. . . [a] young person who knows that he or she has no chance to

leave prison before life's end has little incentive to become a

responsible individual."13 Id. at 79.

More recently in Miller, 567 U.S. at 476, in which the

Court held that a judge must be able to consider "mitigating

qualities of youth" in formulating a sentence, the Court

reiterated that youth is not simply a "chronological fact"

(citation omitted). Rather, "[i]t is a time of immaturity,

irresponsibility, impetuousness[,] and recklessness. . . . It

is a moment and condition of life when a person may be most

susceptible to influence and to psychological damage. . . . And

its signature qualities are all transient" (citations and

quotations omitted). Id. As a result, the Court reasoned, the

Eighth Amendment forbids a sentencing scheme that mandates life

13Although Graham's ban on life sentences without the

possibility of parole for juveniles applied only to nonhomicide

crimes, as the Miller Court pointed out, "none of what [Graham]

said about children -- about their distinctive (and transitory)

mental traits and environmental vulnerabilities -- is crime-

specific." Miller, 567 U.S. at 473.

14

without parole for juvenile offenders because such a scheme

precludes a consideration of youth and the circumstances and

characteristics attendant to it. Id. at 479.

Approximately one and one-half years after Miller was

decided, we considered whether sentencing a juvenile offender to

life without the possibility of parole comported with art. 26.

See Diatchenko I, 466 Mass. at 661. Ultimately, this court went

further than Miller and concluded that because it is not

possible to demonstrate that a juvenile offender is

"irretrievably depraved," under the Massachusetts Declaration of

Rights, such a sentence is cruel or unusual as imposed on a

juvenile in any circumstance. Id. at 670-671.

Central to each of the foregoing cases is the "fundamental

precept of justice that punishment for crime should be graduated

and proportioned to both the offender and the offense" (citation

and quotations omitted). Id. at 669. Until now, we have

declined to consider extending Diatchenko I to offenders

eighteen years of age and older. See Watt, 484 Mass. at 755-

756, and cases cited. However, we also recognized that

"researchers continue to study the age range at which most

individuals reach adult neurobiological maturity . . . and that

such research may relate to the constitutionality of sentences

of life without parole for individuals other than juveniles"

(citation and quotation omitted). Id. The judge's findings in

15

this case, described more fully infra, confirm that the brains

of emerging adults are similar to those of juveniles.

b. Contemporary standards of decency. An assessment of a

punishment's proportionality occurs "in light of contemporary

standards of decency which mark the progress of society."

Diatchenko I, 466 Mass. at 669, quoting Good v. Commissioner of

Correction, 417 Mass. 329, 335 (1994). See Okoro, 471 Mass. at

61 (proportionality of punishment is determined based on "the

evolving standards of decency that mark the progress of a

maturing society" [citation omitted]). Here, we consider the

updated research on the brains of emerging adults, as well as

the way emerging adults are treated in the Commonwealth and

elsewhere, to determine whether a sentence of life without the

possibility of parole is proportionate and thus constitutional

when imposed upon that class of offenders.

i. Science and social science. As mentioned supra, where

modern scientific consensus regarding a particular class exists,

it can be useful in determining the contemporary standards of

decency as they relate to that class. See Miller, 567 U.S. at

471-472; Okoro, 471 Mass. at 59-60.

Advancements in scientific research have confirmed what

many know well through experience: the brains of emerging

adults are not fully mature. Specifically, the scientific

record strongly supports the contention that emerging adults

16

have the same core neurological characteristics as juveniles

have. As the Superior Court judge noted, "Today,

neuroscientists and behavioral psychologists know significantly

more about the structure and function of the brains of

[eighteen] through [twenty year olds] than they did [twenty]

years ago . . . ." This is the result of years of targeted

research and greater access to relatively new and sophisticated

brain imaging techniques, such as structural magnetic resonance

imaging (sMRI) and functional magnetic resonance imaging

(fMRI).14 From the detailed evidence produced in the record, the

judge made four core findings of fact regarding the science of

emerging adult brains: emerging adults (1) have a lack of

impulse control similar to sixteen and seventeen year olds in

emotionally arousing situations,15 (2) are more prone to risk

taking in pursuit of rewards than those under eighteen years and

those over twenty-one years, (3) are more susceptible to peer

14 sMRIs allow researchers to examine the brain's anatomical

structures at particular moments in time; fMRIs allow

researchers to examine the brain's activation and responses to

stimuli and environmental context. As Galván testified, MRIs,

particularly sMRIs, have allowed researchers "to see [a] fine

grain view of the brain that other technologies would not

allow."

15This also is referred to as being under "hot cognition."

The experts testified that under "cold cognition," which is the

absence of emotionally arousing circumstances, the emerging

adult brain functions much more similarly to the older adult

brain than to the adolescent brain.

17

influence than individuals over twenty-one years, and (4) have a

greater capacity for change than older individuals due to the

plasticity of their brains. The driving forces behind these

behavioral differences are the anatomical and physiological

differences between the brains of emerging and older adults.

See Steinberg, A Social Neuroscience Perspective on Adolescent

Risk-Taking, 28 Developmental Rev. 78, 82-84, 85-89 (2008).

These structural and functional differences make emerging

adults, like juveniles, "particularly vulnerable to risk-taking

that can lead to poor outcomes."

We discuss each of the judge's four core factual findings

in turn.

A. Impulse control. The judge found that in terms of

impulse control, emerging adults are more similar to sixteen and

seventeen year old juveniles than to older adults. That is,

they are less able to control their impulses in emotionally

arousing situations. This finding is well supported by the

record.

Emerging adults still are experiencing the effects of "the

sharp increase during puberty of certain hormones," lack a fully

developed prefrontal cortex, which is "the part of the brain

that most clearly regulates impulses," and lack fully developed

connections "between the prefrontal cortex and other parts of

the brain . . . that most clearly respond[] to rewards and

18

reward-related decision making." All four experts agreed that

compared to older adults, emerging adults are more impulsive,

more concerned with their immediate circumstances, and less able

to envision future consequences. Galván explained that at least

part of this distinction between emerging and older adults can

be traced to differences in brain structure between the groups.

"[T]he prefrontal cortex is the home for these abilities that we

might say are what makes us adults . . . the ability to reason,

the ability to think about how your actions today will have

implications for the future." As the brain matures, it

"undergoes a process called pruning and [eliminates]" synapses

and neurons that are not needed. Advancements in sMRI data have

allowed researchers "to measure this cortical thickness and

thinning and the process continues through [eighteen],

[nineteen], [twenty] years old."

All of the other experts, including the Commonwealth's

expert, agreed that the prefrontal cortex, an area of the brain

associated with controlling impulses, is among the last brain

regions to develop, and continues developing until the early to

mid-twenties. See Icenogle et al., Adolescents' Cognitive

Capacity Reaches Adult Levels Prior to Their Psychosocial

Maturity: Evidence for a "Maturity Gap" in a Multinational,

Cross-Sectional Sample, 43 Law & Hum. Behav. 69, 70 (2019);

Sowell & others, In Vivo Evidence for Post-Adolescent Brain

19

Maturation in Frontal and Striatal Regions, 2 Nature Neurosci.

859, 860-861 (1999); Steinberg et al., Around the World,

Adolescence Is a Time of Heightened Sensation Seeking and

Immature Self-Regulation, Developmental Sci., vol. 21, Mar.

2018, at 1-4, 15-17.

B. Risk taking in pursuit of reward. The judge found that

"[a]s a group, [individuals eighteen through twenty years of

age] in the United States and other countries are more prone to

'sensation seeking,' which includes risk-taking in pursuit of

rewards, than are individuals under age [eighteen] and over age

[twenty-one]." This finding similarly is well supported by the

record.

All of the experts agreed that emerging adults are more

likely than children or older adults to engage in risky behavior

and that risky behaviors tend to peak in late adolescence to

early adulthood and then decline, with some experts asserting

that this behavior plateaus around twenty-two years of age.

Galván explained that fMRI studies evaluating the brain have

shown that in individuals at least seventeen years of age, and

up to twenty-one years of age, there is greater activity in the

nucleus accumbens, a part of the brain associated with sensation

seeking, than in older adults. Additionally, fMRI studies have

shown that the ventral striatum, a part of the brain that

correlates with risk-taking behaviors, also is more active among

20

late adolescents and early adults than it is in older adults.

This research tracks numerous real-world behaviors. Emerging

adults are overrepresented in multiple types of risky behavior,

such as risky sexual behavior and risky driving behavior, in

addition to risky criminal behavior. See Roper, 543 U.S. at

569, quoting Arnett, Reckless Behavior in Adolescence: A

Developmental Perspective, 12 Developmental Rev. 339 (1992) ("It

has been noted that 'adolescents are overrepresented

statistically in virtually every category of reckless

behavior'").

Each expert discussed the so-called "age-crime curve,"

which is a widely recognized phenomenon illustrating that

criminal behavior crests at some point from late adolescence to

early adulthood before significantly declining. Put succinctly,

as with those under eighteen years of age, "late adolescence[16]

16All the experts referred to individuals from eighteen to

twenty years of age as "late adolescents." We refer to this age

group as "emerging adults." We do not agree with the dissent

that this appellation indicates that we improperly are veering

into the Legislature's lane. As the Supreme Court noted when it

declared the death penalty unconstitutional for juveniles, line

drawing is a necessary task when considering categorical bans on

unconstitutional sentences. Roper, 543 U.S. at 574 ("Drawing

the line at [eighteen] years of age is subject, of course, to

the objections always raised against categorical rules. The

qualities that distinguish juveniles from adults do not

disappear when an individual turns [eighteen]. By the same

token, some under [eighteen] have already attained a level of

maturity some adults will never reach. For the reasons we have

discussed, however, a line must be drawn").

21

is a period in human development of increased risk taking,

greater reactivity to high stress or highly emotionally arousing

events and certain kinds of cognitive biases that, for example,

lead them [(i.e., juveniles and emerging adults)] to not

appraise a risk and apply it to themselves in the same way that

an adult would." See Galván et al., Earlier Development of the

Accumbens Relative to Orbitalfrontal Cortex Might Underlie Risk-

Taking Behaviors in Adolescents, 26 J. Neurosci. 6885, 6885-6892

(2006); Hawes et al., Modulation of Reward-Related Neural

Activation on Sensation Seeking across Development, 283

NeuroImage 763, 763-771 (2017); Rudolph et al., At Risk of Being

Risky: The Relationship Between "Brain Age" under Emotional

States and Risk Preference, Developmental Cognitive Neurosci.,

vol. 24, 2017, at 93-106; Steinberg et al., Around the World,

Adolescence Is a Time of Heightened Sensation Seeking and

Immature Self-Regulation, supra at 1-4, 15-17.

C. Peer influence. The judge also found that emerging

adults "are more susceptible to peer influence" than older

adults and that the presence of peers makes emerging adults

"more likely to engage in risky behavior." All four experts

agreed that current research supports this conclusion.

Steinberg's research in particular focuses on the ways in

which the presence of peers affects decision-making and risk

taking among different age groups. In his work, he has found

22

that "even if the peers aren't explicitly encouraging anything,

the mere presence of peers increases the likelihood that

adolescents[17] will engage in [risky] behavior." Although the

presence of peers may influence behavior at any age, "peer

influence is a much more serein [sic] and powerful factor during

adolescence[18] than it is during adulthood." See Breiner et al.,

Combined Effects of Peer Presence, Social Cues, and Rewards on

Cognitive Control in Adolescents, 60 Developmental Psychobiology

292, 292-302 (2018); Galván, Adolescent Brain Development and

Contextual Influences: A Decade in Review, 31 J. Res. on

Adolescence 843, 852-853 (2021); Silva et al., Peers Increase

Late Adolescents' Exploratory Behavior and Sensitivity to

Positive and Negative Feedback, 26 J. Res. on Adolescence 696,

696-705 (2015).

D. Capacity for change. Finally, the judge found that

emerging adults "have greater capacity to change than older

individuals because of the plasticity of the brain during these

years." This finding is well supported by the record.

"[P]lasticity refers to the ability [to] change in response

to the environment."19 Although the brain has its greatest

17 See note 16, supra.

18 See note 16, supra.

19Galván explained that plasticity primarily occurs in the

hippocampus, which is "a small brain region in the deep layers

23

plasticity in the early months of life, as Galván explained,

"[t]he second wave [of plasticity] is during adolescence."20 In

contrast, "adult capacity for change is diminished because" the

fully mature brain is much less malleable. Although the brain

continues to change throughout one's lifespan, Steinberg

testified that brain maturation is largely complete by as early

as twenty-two years of age, and possibly up to twenty-five years

of age. The Commonwealth's expert agreed that "[m]ost

adolescents[21] even those who commit serious crimes will age out

of offending and will not become career criminals." See Roper,

543 U.S. at 570, quoting Johnson, 509 U.S. at 368, and citing

Steinberg & Scott, Less Guilty by Reason of Adolescence:

Developmental Immaturity, Diminished Responsibility, and the

Juvenile Death Penalty, 58 Am. Psychologist 1009, 1014 (2003)

("the signature qualities of youth are transient; as individuals

mature, the impetuousness and recklessness that may dominate in

younger years can subside"). See also Cauffman et al., A

Developmental Perspective on Adolescent Risk-Taking and Criminal

Behavior, c. 6 in The Handbook of Criminological Theory (2015);

of the brain that has mostly been studied in the context of

learning because plasticity or any plasticity-based changes are

because we've learned something new."

20 See note 16, supra.

21 See note 16, supra.

24

Galván, Insights about Adolescent Behavior, Plasticity, and

Policy from Neuroscience Research, 83 Neuron 262, 264 (2014).

The evidence outlined supra provides a scientifically

informed view of emerging adults' culpability and factors into

our analysis whether contemporary standards of decency permit

sentencing that cohort to life without the possibility of

parole.

ii. Treatment of emerging adults in the Commonwealth and

elsewhere. To determine our contemporary standards of decency,

in addition to referring to our own State statutes, see Good,

417 Mass. at 335, we may look to other policies and programs in

the Commonwealth, our precedent, other States' statutes, as well

as other States' judicial rulings, and even international

statutes and decisions, among other sources, see Okoro, 471

Mass. at 61 (we commonly look to "judicial opinions and

legislative actions at the State, Federal, and international

levels," which "help to inform our understanding of what art. 26

protects" [citation omitted]). See also Thompson v. Oklahoma,

487 U.S. 815, 821-831 (1988) (looking to State statutes and

death penalty juries to divine contemporary standards of

decency, and noting consistency with practices of other

nations); Enmund v. Florida, 458 U.S. 782, 788 (1982) (looking

to "historical development of the punishment at issue,

legislative judgments, international opinion, and the sentencing

25

decisions juries have made"); Coker v. Georgia, 433 U.S. 584,

596 (1977) ("important to look to the sentencing decisions that

juries have made in the course of assessing whether capital

punishment is an appropriate penalty"). As discussed infra, a

combination of statutes passed here and elsewhere, as well as

recent decisions in Washington and Michigan, indicate that our

contemporary standards of decency do not support imposing life

without parole sentences on emerging adults.

To begin, the Legislature has determined that emerging

adults require different treatment from older adults,

specifically in the penological context. For example, the

Department of Youth Services (department) statutorily is

authorized to maintain custody of young people adjudicated as

youthful offenders up to twenty-one years of age. See

Commonwealth v. Terrell, 486 Mass. 596, 599-600, 603 (2021);

G. L. c. 119, § 58. This sentencing scheme also permits the

imposition of "dual" sentences for youthful offenders, requiring

them to remain in the department's custody until they are

twenty-one years of age before beginning their "adult sentence"

at a house of correction. G. L. c. 119, § 58 (b).

Further, in 2018, as part of a set of sweeping reforms, the

Legislature authorized the Department of Correction and county

houses of correction to "establish young adult correctional

units." These units provide "targeted interventions, age

26

appropriate programming and a greater degree of individual

attention" for individuals in custody "ages [eighteen] to

[twenty-four]." G. L. c. 127, § 48B (a). Notably, the

Legislature also formed the Task Force on Emerging Adults in the

Criminal Justice System (task force), which released a report in

2020 concluding that emerging adults "are a unique population

that requires developmentally-tailored programming and

services."22 Emerging Adults in the Massachusetts Criminal

Justice System: Report of the Task Force on Emerging Adults in

the Criminal Justice System (Feb. 26, 2020), 2020 Senate Doc.

No. 2840, at 6. See St. 2018, c. 69, § 221.

Massachusetts is not alone in recognizing that emerging

adult offenders require different treatment from older adult

offenders. For example, the District of Columbia now provides a

22 Noting that the dual sentencing scheme for youthful

offenders under G. L. c. 119, § 58, applies only to juveniles,

and that the task force's recommendations for emerging adults do

not include offenders convicted of murder in the first degree,

Justice Lowy's dissent concludes that neither demonstrates

contemporary standards of decency here in the Commonwealth.

Post at . See G. L. c. 119, § 74; Emerging Adults in the

Massachusetts Criminal Justice System: Report of the Task Force

on Emerging Adults in the Criminal Justice System (Feb. 26,

2020), 2020 Senate Doc. No. 2840, at 10. To the contrary, both

examples demonstrate that the Legislature and other community

members recognize that emerging adult offenders benefit from

being treated differently from older adult offenders. Cf.

Thompson v. Oklahoma, 487 U.S. 815, 823 (1988) (distinct

treatment of younger juveniles compared to older juveniles "in

criminal sanctions and rehabilitation" is evidence of

contemporary standards of decency [citation omitted]).

27

chance at sentence reduction for people who were under twenty-

five years old when they committed a crime. D.C. Code § 24-

403.03. In 2019, Illinois enacted a law allowing parole review

at ten or twenty years into a sentence for most crimes,

exclusive of sentences to life without parole, if the individual

was under twenty-one years old at the time of the offense. 730

Ill. Comp. Stat. 5/5-4.5-115. Effective January 1, 2024,

Illinois also ended life without parole for most individuals

under twenty-one years old, allowing review after they serve

forty years. Ill. Pub. L. No. 102-1128, § 5 (2022). California

has extended youth offender parole eligibility to individuals

who committed offenses before twenty-five years of age. Cal.

Penal Code § 3051. Similarly, in 2021, Colorado expanded

specialized program eligibility, usually reserved for juveniles,

to adults who were under twenty-one when they committed a

felony. Colo. House Bill No. 21-1209 (2021) (enacted). In

Wyoming, "youthful offender" programs were revised to offer

reduced and alternative sentencing for those under thirty years

old. Wyo. Stat. Ann. §§ 7-13-1002, 7-13-1003.

Legislation outside of the penological context is also

instructive in ascertaining contemporary standards of decency.

In Thompson, 487 U.S. at 838, the Supreme Court determined that

the death penalty was unconstitutional when imposed on a fifteen

year old offender based, in part, on then-current nonpenological

28

State statutes that treated younger juveniles differently from

those closer to age eighteen. Among other things, the Court

noted that "in all but one State a [fifteen]-year-old may not

drive without parental consent, and in all but four States a

[fifteen]-year-old may not marry without parental consent"

(footnote omitted). See id. at 824-825.

Similarly, Massachusetts, like most States, distinguishes

emerging adults from older adults on a range of issues, granting

rights and imposing responsibilities in a graduated manner. For

example, one must be eighteen years of age to enter binding and

enforceable contracts, to sit on a jury, to purchase lottery

tickets, and to drive a common carrier motor vehicle.23 See

G. L. c. 231, § 85O; G. L. c. 234A, § 4; G. L. c. 10, § 29;

G. L. c. 159A, § 9. However, one must be twenty-one years of

age to purchase and sell alcoholic beverages, to purchase

tobacco products, to obtain a license to carry a handgun, to be

a police officer, and to gamble. See G. L. c. 138, § 34; G. L.

c. 270, § 6; G. L. c. 140, § 131 (d) (iv); G. L. c. 31, § 58;

G. L. c. 22C, § 10; G. L. c. 23K, §§ 25 (h), 43. These statutes

reflect the commonly held view that emerging adults generally

23Moreover, young adults who have reached eighteen years of

age may "continue to be considered 'minors'" for purposes of

parental support. Eccleston v. Bankosky, 438 Mass. 428, 429

(2003), quoting Stolk v. Stolk, 31 Mass. App. Ct. 903, 904-905

(1991). See G. L. c. 208, § 28.

29

are not equipped to assume all the responsibilities of

adulthood, especially with respect to high risk activities. Cf.

Thompson, 487 U.S. at 824-825.

We are not the first State Supreme Court to appreciate the

distinct ways in which our laws bear on emerging adults.

Recently, the high courts in Washington and Michigan prohibited

the mandatory imposition of life without the possibility of

parole for those who are from eighteen to twenty years of age,

and for those who are eighteen years of age, respectively. In

Matter of the Personal Restraint of Monschke, 197 Wash. 2d 305

(2021), the Supreme Court of Washington considered evolving

standards of decency, updated brain science, and precedent to

conclude that mandatory sentences of life without parole violate

the Washington Constitution when meted out to those under

twenty-one when they committed the crime. See id. at 325-326.

One year later, the Supreme Court of Michigan looked at the

issue as it pertained to eighteen year old offenders. The court

reasoned that because "the Eighth Amendment dictates that youth

matters in sentencing," and because brain science has

demonstrated that eighteen year old individuals possess the same

attributes of youth as do juveniles, mandatorily subjecting an

eighteen year old defendant to life in prison is "unusually

excessive imprisonment and thus a disproportionate sentence that

constitutes 'cruel or unusual punishment' under [the Michigan

30

Constitution]." People v. Parks, 510 Mich. 225, 234, 255

(2022).24

Twenty-two States and the District of Columbia do not

mandate life without parole in any circumstance.25 Of the

remaining twenty-eight States, only twelve (including

Massachusetts) mandate life without parole.26 Moreover, the

24However, both the Washington and Michigan courts

determined that a sentence of life without the possibility of

parole could be imposed on young adult offenders after an

individualized sentencing hearing to consider the offender's

youth. See Parks, 510 Mich. at 240-241; Matter of the Personal

Restraint of Monschke, 197 Wash. 2d at 327-328.

25In those twenty-two States and the District of Columbia,

the highest penalties are imposed only on discretionary bases.

See Alaska Stat. § 12.55.125; D.C. Code § 22-2104; Ga. Code Ann.

§ 16-5-1; Idaho Code Ann. §§ 18-4004, 19-2515; 720 Ill. Comp.

Stat. 5/9-1; Ind. Code §§ 35-50-2-3, 35-50-2-9; Ky. Rev. Stat.

Ann. § 532.030; Me. Rev. Stat. tit. 17-A, § 1603; Md. Code Ann.,

Crim. Law §§ 2-201, 2-203; Mont. Code Ann. § 45-5-102(2); Nev.

Rev. Stat. § 200.030(4)(a)-(b); N.M. Stat. Ann. § 31-18-13; N.Y.

Penal Law §§ 60.06, 70.00(5); N.D. Cent. Code § 12.1-32-01; Ohio

Rev. Code Ann. §§ 2929.02, 2929.04; Okla. Stat. tit. 21,

§ 701.9; Or. Rev. Stat. § 163.107; R.I. Gen. Laws §§ 11-23-2,

12-19.2-1 to 12-19.2-5; S.C. Code Ann. § 16-3-20; Tenn. Code

Ann. § 39-13-204; Utah Code Ann. § 76-5-203; Wis. Stat.

§ 973.014(1g)(c)-(2); Wyo. Stat. Ann. § 6-2-101.

26See G. L. c. 265, § 2 (a) ("any person who is found

guilty of murder in the first degree shall be punished by

imprisonment in the state prison for life and shall not be

eligible for parole pursuant to [G. L. c. 127, § 133A"); Colo.

Rev. Stat. § 18-1.3-401(1)(a)(V)(F), (4)(a)(I)-(II) ("A person

. . . shall be punished by life imprisonment" without

possibility of parole); Del. Code Ann. tit. 11, § 4209 ("Any

person who is convicted of first-degree murder for an offense

that was committed after the person had reached [his or her]

eighteenth birthday shall be punished by . . . imprisonment for

the remainder of the person's natural life without benefit of

probation or parole or any other reduction"); Haw. Rev. Stat.

31

statutes in at least two of those States provide an opportunity

to avoid the mandatory nature of the sentence.27 Twelve States

mandate life without parole as an alternative to a discretionary

death sentence,28 and five States only mandate life without

§ 706-656 ("Persons eighteen years of age or over at the time of

the offense who are convicted of first degree murder or first

degree attempted murder shall be sentenced to life imprisonment

without the possibility of parole"); Iowa Code § 902.1 (on

conviction of murder in first degree, "the court shall . . .

commit the defendant . . . for the rest of the defendant's life

. . . [and the defendant] shall not be released on parole unless

the governor commutes the sentence to a term of years"); Mich.

Comp. Laws § 750.316 (any person "who commits . . . first degree

murder . . . shall be punished by imprisonment for life without

eligibility for parole"); Minn. Stat. § 609.106 ("the court

shall sentence a person to life imprisonment without possibility

of release . . . [if] the person is convicted of first-degree

murder"); N.H. Rev. Stat. Ann. § 630:1-a(III) ("A person

convicted of a murder in the first degree shall be sentenced to

life imprisonment and shall not be eligible for parole at any

time"); 18 Pa. Cons. Stat. § 1102 ("a person who has been

convicted of a murder of the first degree . . . shall be

sentenced to . . . a term of life imprisonment"); Va. Code Ann.

§ 18.2-10(a) ("Any person who was [eighteen] years of age or

older at the time of the offense and who is sentenced to

imprisonment for life upon conviction of a Class 1 felony shall

not be eligible for . . . parole"); Wash. Rev. Code § 10.95.030

(any person "convicted of the crime of aggravated first degree

murder shall be sentenced to life imprisonment without

possibility of release or parole"); W. Va. Code § 61-2-2

("Murder of the first degree shall be punished by confinement in

the penitentiary for life").

27Iowa allows its Governor to commute the sentence to a

term of years. Iowa Code § 902.2. Hawaii obligates the parole

board to submit an application to its Governor to commute the

sentence to one permitting parole after twenty years. Haw. Rev.

Stat. § 706-656.

28See Ala. Code § 13a-6-2(c); Ariz. Rev. Stat. Ann. §§ 13-

751(A), 13-1105(D); Ark. Code Ann. § 5-10-101(c); Fla. Stat.

§ 775.082; Kan. Stat. Ann. § 21-6617 (for capital murder); La.

32

parole if aggravating circumstances exist.29 Massachusetts is

one of only ten States that currently require eighteen through

twenty year old individuals who are convicted of murder in the

first degree to be sentenced to life without parole.

We also may consider where other nations stand in this

analysis. See Okoro, 471 Mass. at 61. See also Graham, 560

U.S. at 80 ("The judgments of other nations and the

international community are not dispositive as to the meaning of

the Eighth Amendment," but "[t]he Court has looked beyond our

Nation's borders for support for its independent conclusion that

a particular punishment is cruel and unusual"). The United

Kingdom has banned life without parole for any offender under

twenty-one years of age at the time of the offense. Sentencing

Act 2020, c. 17, § 322, sch. 21, par. 2 (U.K.). And in 2022,

the Supreme Court of Canada unanimously ruled that life without

parole sentences were unconstitutional for all offenders,

regardless of age. R. v. Bissonnette, 2022 SCC 23. The

foregoing examples suggest that the "evolving standards of

decency that mark the progress of a maturing society" referenced

Rev. Stat. Ann. § 14:30(C); Miss. Code Ann. §§ 47-7-3(1)(d), 97-

3-21; Mo. Rev. Stat. § 565.020; Neb. Rev. Stat. § 28-105; N.C.

Gen. Stat. § 14-17; S.D. Codified Laws § 22-6-1; Tex. Penal Code

Ann. § 12.31.

29See Cal. Penal Code § 190.2; Conn. Gen. Stat. §§ 53a-

35a(1)(B), 53a-54b; N.J. Stat. Ann. § 2C:11-3; Va. Code Ann.

§§ 18.2-10, 18.2-31; Vt. Stat. Ann. tit. 13, § 2303.

33

in Miller, 567 U.S. at 469, trend away from life without parole

for emerging adults (citation omitted).

2. Life without parole for emerging adults violates art.

26. Our comprehensive review informs us that Supreme Court

precedent, as well as our own, dictates that youthful

characteristics must be considered in sentencing, that the

brains of emerging adults are not fully developed and are more

similar to those of juveniles than older adults, and that our

contemporary standards of decency in the Commonwealth and

elsewhere disfavor imposing the Commonwealth's harshest sentence

on this cohort. Consequently, we conclude that a sentence of

life without the possibility of parole for emerging adult

offenders violates art. 26.30 See Diatchenko I, 466 Mass. at

670.

3. Remedy. Because we have determined that it is

unconstitutional to sentence emerging adults to life without the

possibility of parole, we invalidate those provisions of our

The contemporary standards of decency that govern our

30

decision today do not suggest a societal consensus that those

aged twenty-one and above should be treated differently from

older adults. Thus, while we acknowledge that the scientific

record in this case suggests that the unique attributes of youth

may persist in young adults older than twenty-one, our art. 26

proportionality analysis does not rely on science alone. See

Libby v. Commissioner of Correction, 385 Mass. 421, 435 (1982),

quoting District Attorney for the Suffolk Dist. v. Watson, 381

Mass. 648, 661-662 (1980) ("Article 26, like the Eighth

Amendment, bars punishments which are 'unacceptable under

contemporary moral standards'").

34

criminal code that deny the possibility of parole to this

cohort. General Laws c. 265, § 2, which was amended after

Diatchenko I was decided, sets forth the penalty for murder in

the first degree, distinguishing between the penalties for

adults and juveniles:

"(a) Except as provided in subsection (b), any person who

is found guilty of murder in the first degree shall be

punished by imprisonment in the [S]tate prison for life and

shall not be eligible for parole pursuant to [G. L. c. 127,

§ 133A].

"(b) Any person who is found guilty of murder in the first

degree who committed the offense on or after the person's

fourteenth birthday and before the person's eighteenth

birthday shall be punished by imprisonment in the [S]tate

prison for life and shall be eligible for parole after the

term of years fixed by the court pursuant to [G. L. c. 279,

§ 24]."

Although we hold that it is unconstitutional to sentence

individuals from eighteen to twenty years of age to life without

the possibility of parole, we must "as far as possible, . . .

hold the remainder [of the statute] to be constitutional and

valid, if the parts are capable of separation and are not so

entwined that the Legislature could not have intended that the

part otherwise valid should take effect without the invalid

part." Diatchenko I, 466 Mass. at 672, quoting Boston Gas Co.

v. Department of Pub. Utils., 387 Mass. 531, 540 (1982). See

G. L. c. 4, § 6, Eleventh ("The provisions of any statute shall

be deemed severable, and if any part of any statute shall be

adjudged unconstitutional or invalid, such judgment shall not

35

affect other valid parts thereof").31 Here, because emerging

adults do not fit within the exception described in G. L.

c. 265, § 2 (b), we must invalidate that portion of G. L.

c. 265, § 2 (a), that denies parole eligibility to those from

eighteen to twenty years old. See Diatchenko I, supra at 673.

Likewise, we also must invalidate that portion of the parole

statute, G. L. c. 127, § 133A, that denies parole to those from

eighteen to twenty years of age.32

Because the Legislature does not currently provide a parole

eligibility scheme for this category of offenders, we look to

the next-most severe sentence under the sentencing scheme to

determine the floor of parole eligibility. See Watt, 484 Mass.

at 753-754, citing Diatchenko I, 466 Mass. at 672-673. For

emerging adults convicted of murder in the first degree on or

31Notably, the Legislature specifically provides for the

severability of G. L. c. 265, § 2. See St. 1982, c. 554, § 7

("If any of the provisions of [G. L. c. 265, § 2,] or the

application thereof to any person or circumstances is held

invalid, such invalidity shall not affect other provisions or

applications of this act which can be given effect without the

invalid provisions or applications, and to this end the

provisions of this act are declared severable").

32 General Laws c. 127, § 133A, states in relevant part:

"Every prisoner who is serving a sentence for life in a

correctional institution of the commonwealth, . . . except

prisoners serving a life sentence for murder in the first

degree who had attained the age of [eighteen] years at the

time of the murder . . . shall be eligible for parole at

the expiration of the minimum term fixed by the court under

[G. L. c. 279, § 24]."

36

after today's decision, that means applying G. L. c. 279, § 24,

as amended through St. 2014, c. 189, § 6, which sets parole

eligibility for juvenile offenders who have committed murder in

the first degree:

"In the case of a sentence of life imprisonment for murder

in the first degree committed by a [juvenile], the court

shall fix a minimum term of not less than [twenty] years

nor more than [thirty] years; provided, however, that in

the case of a sentence of life imprisonment for murder in

the first degree with extreme atrocity or cruelty committed

by a [juvenile], the court shall fix a minimum term of

[thirty] years; and provided further, that in the case of a

sentence of life imprisonment for murder in the first

degree with deliberately premeditated malice aforethought

committed by a [juvenile], the court shall fix a minimum

term of not less than [twenty-five] years nor more than

[thirty] years."

However, the defendant in this case was sentenced to life

without the possibility of parole pursuant to G. L. c. 265,

§ 2 (a), prior to the enactment of the aforementioned

legislative changes in 2014, post-Diatchenko I. Therefore, this

defendant and other emerging adults sentenced to life without

the possibility of parole prior to July 25, 2014, may only be

resentenced to the constitutionally permissible penalty

available at that time -- life with the possibility of parole

after fifteen years. See Commonwealth v. Costa, 472 Mass. 139,

146 (2015) (resentencing limited to available statutory penalty

in effect at time of conviction).

By providing an opportunity for parole, we do not diminish

the severity of the crime of murder in the first degree because

37

it was committed by an emerging adult. Likewise, our decision

today "should not be construed" to suggest that emerging adults

receiving the benefit of resentencing under today's holding

"should be paroled once they have served a statutorily

designated portion of their sentences." Diatchenko I, 466 Mass.

at 674. However, as we stated in Diatchenko I, we must

recognize the "unique characteristics" of emerging adults that

render them "constitutionally different" from adults for

purposes of sentencing. Id., citing Miller, 567 U.S. at 471.

As such, they must be granted a "meaningful opportunity to

obtain release based on demonstrated maturity and

rehabilitation" before the Massachusetts parole board, who will

"evaluate the circumstances surrounding the commission of the

crime, including the age of the offender, together with all

relevant information pertaining to the offender's character and

actions during the intervening years since conviction."

Diatchenko I, supra, quoting Graham, 560 U.S. at 75.

Conclusion. We remand this matter to the Superior Court

for resentencing consistent with this opinion.

So ordered.

KAFKER, J. (concurring). I concur with the court's

comprehensive review of the expert testimony, the judge's fact

finding, and the applicable law. I write separately to

emphasize in particular that the letter and spirit of our

trailblazing decision in Diatchenko v. District Attorney for the

Suffolk Dist., 466 Mass. 655, 669 (2013) (Diatchenko I), S.C.,

471 Mass. 12 (2015) (Diatchenko II), directs us to reach the

same conclusion today that we reached a decade ago and extend

those very same protections to the age group at issue --

eighteen through twenty year olds.

In our landmark decision in Diatchenko I, we relied on the

best science available at the time, legislative recognition of

the legal differences between juveniles and adults in other

contexts, and the special protections of art. 26 of the

Massachusetts Declaration of Rights to declare that the

Legislature's imposition of life sentences without the

possibility of parole for juveniles was unconstitutional,

because juveniles are less culpable than adults and more capable

of change. We also employed distinctive reasoning that I

discuss in some detail infra. In so doing, we provided greater

protections for juveniles under art. 26 than the United States

Supreme Court had under the Eighth Amendment to the United

States Constitution, precluding not only mandatory life

sentences without the possibility of parole but also

2

discretionary sentences of life without the possibility of

parole.

In the instant case, we are presented with comprehensive

fact finding evaluating further advancements in developmental

cognitive neuroscience and developmental psychology,1

demonstrating that eighteen through twenty year olds share the

same characteristics that distinguished juveniles from adults in

Diatchenko I and that rendered them less culpable and more

capable of change. The extensive briefing also demonstrates

legislative recognition that eighteen through twenty year olds

similarly require differential treatment from those twenty-one

and older in other relevant and related contexts. Indeed, when

this age group has been recognized by the Legislature to require

differential treatment, the legal rights in question implicate

those same distinctive characteristics.

Due to this convergence of science and law, I conclude that

art. 26 precludes both mandatory and discretionary life

1 As one of the experts testified, the fields of

developmental cognitive neuroscience and developmental

psychology work in tandem with one another. "Cognitive

neuroscience is the study of the brain and the cognitive

operations . . . the brain supports, including thinking and

decision-making," or "higher cognitive tasks or operation[s],"

while the "developmental component" refers "to the study of the

brain as it develops over time and across the lifespan."

Comparatively, "developmental . . . psychology is concerned with

behavior," and often "the research studies that are conducted in

developmental neuroscience are first informed by behaviors that

are observed in studies of development[al] psychology."

3

sentences without the possibility of parole for those who are

older than eighteen but younger than twenty-one at the time they

committed murder in the first degree. Thus, after serving from

twenty-five to thirty years in prison as now prescribed by the

Legislature for juvenile murderers, these eighteen through

twenty year olds likewise shall have the possibility of

convincing the parole board that they have redeemed themselves

in prison, have taken responsibility for the terrible deaths

that they caused in their youth, and deserve to be paroled.2

1. Discussion. a. Diatchenko, differentiating

characteristics, and State constitutional law. Our reasoning in

Diatchenko I built on the foundation of the United States

Supreme Court's Eighth Amendment analysis in Miller v. Alabama,

567 U.S. 460 (2012), particularly "three significant

characteristics differentiating juveniles from adult offenders."

Diatchenko I, 466 Mass. at 660.

"First, children demonstrate a lack of maturity and an

underdeveloped sense of responsibility, leading to

recklessness, impulsivity, and heedless risk-taking.

Second, children are more vulnerable to negative influences

and outside pressures, including from their family and

peers . . . . Finally, a child's character is not as well

formed as an adult's; his traits are less fixed and his

2 I note that the defendant here was convicted prior to the

passage of the 2014 legislation that required from twenty-five

to thirty years before parole eligibility, and thus is eligible

for consideration for parole, as this court explained in

Diatchenko I, after fifteen years in prison. See Diatchenko I,

466 Mass. at 673-674 (explaining reasons for fifteen year parole

eligibility date at time).

4

actions less likely to be evidence of irretrievable

depravity." (Quotations, citations, and alterations

omitted.)

Id. Together, these characteristics demonstrated that juveniles

possessed "diminished culpability" and a "heightened capacity

for change." Cf. id. at 661, quoting Miller, supra at 479.

Recognizing these differences and "[a]n ever-growing body of

research in developmental psychology and neuroscience [that]

continues to confirm and strengthen the Court's conclusions,"

Miller, supra at 472 n.5, the Supreme Court concluded that a

mandatory imposition of a sentence of life without the

possibility of parole for juveniles was cruel and unusual in

violation of the Eighth Amendment, id. at 479. The Court did,

however, allow a discretionary imposition of this sentence based

on an individualized hearing, requiring judges to consider "how

children are different, and how those differences counsel

against irrevocably sentencing them to a lifetime in prison."

Id. at 480.

We then took a significant additional step in Diatchenko I,

466 Mass. at 670-671, and went well beyond the Supreme Court's

Eighth Amendment protections, concluding that the greater

protection afforded by art. 26 also prohibited the discretionary

imposition of life without parole for juveniles convicted of

murder in the first degree. We determined, consistent with the

scientific evidence presented, that "a conclusive showing of

5

traits such as an 'irretrievably depraved character,' . . . can

never be made, with integrity, by the Commonwealth at an

individualized hearing to determine whether a sentence of life

without parole should be imposed on a juvenile homicide

offender." Id. at 669-670, quoting Roper v. Simmons, 543 U.S.

551, 570 (2005). More specifically, we held that because "the

brain of a juvenile is not fully developed, either structurally

or functionally, by the age of eighteen, a judge cannot find

with confidence that a particular offender, at that point in

time, is irretrievably depraved." Diatchenko I, supra at 670.

Thus, we concluded that our State Constitution prohibited trial

judges from attempting to make individualized findings that were

impossible to make reliably at the time of sentencing, and so we

imposed a categorical ban on the imposition of this sentence for

juveniles. Id. at 669-670.

As the Superior Court judge comprehensively found and as

the court explains in its opinion, the scientific evidence here

demonstrates that the same three characteristics that

distinguished juveniles from adults in Diatchenko I, 466 Mass.

at 669-670, distinguish eighteen through twenty year olds in

essentially the same way. No one disputes those findings or the

6

science on which they are based, including the authors of the

dissenting opinions written in the instant case.3

I therefore emphasize that, based on the fact findings

here, we cannot distinguish in any way this case from Diatchenko

I on scientific grounds. That science was also, as explained

ante, a significant factor in the decision in Diatchenko I, 466

Mass. at 669-670, helping to convince this court to provide

greater protection under the State Constitution than the Supreme

Court provided under the Federal Constitution when the Supreme

Court's allowance of discretionary life without parole sentences

for juveniles who committed murder in the first degree could not

be reconciled with the science. Evolving science helps inform

evolving standards of decency. Cf. Helling v. McKinney, 509

U.S. 25, 36 (1993) (regarding prison conditions, Eighth

Amendment analysis requires both "scientific and statistical

inquiry into the seriousness of the potential harm" and

"assess[ment] whether society considers the risk . . . to be so

3 On remand, the judge heard expert testimony and oral

argument and accepted an additional exhibit in evidence, before

issuing findings of fact and conclusions of law on whether

mandatory life without parole sentences for eighteen through

twenty year old offenders violates art. 26. Neither party

disputes his factual findings. Among those findings, the judge

clarified that his findings were limited to those up to age

twenty-one because, while one expert, Dr. Adriana Galván,

included twenty-one year olds in her developmental cognitive

neuroscience research, another expert, Dr. Laurence Steinberg,

did not include them in his developmental psychology research.

7

grave that it violates contemporary standards of decency"). We

particularly were concerned that trial judges would be required

to make findings that the science demonstrated were not

possible. Diatchenko I, supra. See the amicus brief submitted

by twenty-three retired Massachusetts judges and others, at 36-

40.4

The Supreme Court has, over the vigorous dissent of the

4

author of Miller and two other Justices, since held that, for

the individualized hearings required by the Eighth Amendment, "a

finding of fact regarding a child's incorrigibility is not

required" (quotation, citation, and alteration omitted). Jones

v. Mississippi, 141 S. Ct. 1307, 1314-1315 (2021), quoting

Montgomery v. Louisiana, 577 U.S. 190, 211 (2016). That the

Supreme Court does not now require an explicit finding on

incorrigibility under its line of Eighth Amendment cases does

not change our previous determination under art. 26 that such a

finding is necessary to justify a sentence of life without

parole for those under eighteen because our State constitutional

protections are greater than those of the Eighth Amendment. See

Diatchenko I, 466 Mass. at 670.

Nor is our determination in Diatchenko I inconsistent with

our decision in Commonwealth v. Perez, 477 Mass. 677, 679 (2017)

(Perez I), S.C., 480 Mass. 562 (2018) (Perez II), which required

an individualized hearing "where a juvenile is sentenced for a

nonmurder offense or offenses and the aggregate time to be

served prior to parole eligibility exceeds that applicable to a

juvenile convicted of murder." That hearing is different from

the individualized hearing that we concluded was not possible in

Diatchenko I, 466 Mass. at 669-670, because the hearing required

by Perez I does not concern whether parole eligibility is

necessary, as all juvenile offenders are entitled to parole

eligibility after Diatchenko I. See Perez II, supra at 569.

Rather, it asks judges to consider the permissibility of a

longer term of imprisonment prior to parole eligibility for

nonmurder offenses than for murder in the first degree. See

Perez I, supra; Perez II, supra. Our decision in Perez I, supra

at 686, also established a presumption against such longer

parole eligibility sentences under art. 26 and therefore set a

8

Other important aspects of Diatchenko I also should apply

equally here. We emphasized, for example, that life sentences

without the possibility of parole were deemed particularly

severe for those required to stay in prison from youth to death;

indeed, we went so far as to compare such sentences to the death

penalty, which we already had deemed "unconstitutional under

art. 26." See Diatchenko I, 466 Mass. at 670 (describing life

sentences without possibility of parole for juveniles as being

"strikingly similar" to death penalty). That same reasoning

applies to eighteen through twenty year olds, who likewise are

fated to spend the vast majority of their lives in prison with

no hope of release at any time. If this case is to be

distinguished from Diatchenko I, it must therefore be on other

grounds, each of which I address and reject infra, turning once

again to Diatchenko I for guidance.

b. The Legislature's right to define the punishment for

the crime and distinguish juveniles from adult offenders.

Justices Lowy and Cypher in their dissents emphasize that great

deference is owed to the Legislature's right to define the

punishment for criminal behavior and define the line between

juvenile and adult offenders. See post at , (Lowy, J.,

dissenting); post at (Cypher, J., dissenting). As a general

very high bar to justify them, which we confirmed and clarified

in Perez II, supra at 571-573.

9

principle, I wholeheartedly agree with these propositions. But

in Diatchenko I, we did not defer to the punishment established

by the Legislature or to the line drawing (or, in that case, the

absence of line drawing) between juveniles and adults. Rather,

we concluded that the punishment, without necessary line

drawing, was unconstitutional. Diatchenko I, 466 Mass. at 658-

659. In sum, we did not defer to the Legislature; we concluded

that it acted unconstitutionally.

Unlike the Supreme Court in its line of cases regarding

acceptable criminal punishments for juveniles under the Eighth

Amendment, we also did not define explicitly a fixed

constitutional line for life sentences without the possibility

of parole when we decided Diatchenko I. Compare Roper, 543 U.S.

at 574 ("The age of [eighteen] is the point where society draws

the line for many purposes between childhood and adulthood. It

is, we conclude, the age at which the line for death eligibility

ought to rest" [emphasis added]), with Diatchenko I, 466 Mass.

at 669-670 (relying on "current scientific research on

adolescent brain development" to reach conclusion that "the

judge cannot ascertain, with any reasonable degree of certainty,

whether imposition of this most severe punishment is

warranted"). In defining that line previously in the death

penalty context, the Supreme Court also recognized that it had

itself recently set that line at sixteen and then moved it.

10

Roper, supra at 561-562. Perhaps recognizing that this line was

not fixed for all purposes and might too be a moving target for

sentences of life without the possibility of parole, we did not

attempt such analysis or decide that it was applicable

regardless of the science. Instead, we only answered what we

were asked: whether it was constitutional to sentence

"juveniles" to life without the possibility of parole as the

Legislature provided, and we concluded that it was not, because

the science demonstrated that juveniles were less culpable and

capable of change. Diatchenko I, supra at 671. We then

referenced and relied on a statutory definition of "juvenile" to

define the scope of our holding at the time. Id. at 659 n.8,

673 n.17.5

The question then becomes whether there is a meaningful

constitutional difference between overruling the Legislature's

decision that it is permissible to sentence juveniles to life in

prison without the possibility of parole and overruling the

Legislature's decision that it is permissible to sentence

eighteen through twenty year olds to life in prison without the

possibility of parole, when the fact finding regarding the

5 I do not in any way seek to redefine eighteen through

twenty year olds as juveniles. Rather, I consider eighteen

through twenty year olds as a distinct legal category as

explained infra, as the Legislature itself has done in a variety

of contexts.

11

scientific evidence now conclusively demonstrates that eighteen

through twenty year olds, just like juveniles, are less culpable

for their crimes and more capable of change than adults.

Justices Lowy and Cypher find such a basis in deference to

the Legislature: we should defer to the Legislature because it

did not exclude eighteen to twenty year olds from a statute that

provides for life sentences without the possibility of parole

for murder in the first degree. See post at , (Lowy, J.,

dissenting); post at (Cypher, J., dissenting). The same,

however, was true for juveniles when we decided Diatchenko I,

466 Mass. at 672-673. Although the Legislature at that time

authorized life sentences without the possibility of parole for

juveniles, as explained supra, we found such punishment

unconstitutional. Id.

Justices Lowy and Cypher in their dissents also state that

we should defer to the Legislature because it has defined

eighteen as a fixed line between juveniles and adults.6 I

6 Justice Cypher posits that the extension of rights to

those over the age of eighteen has always been granted first by

the Legislature and not the courts, and so we would be the first

to define protections for a certain category of individuals

based on an age group of our definition. Post at (Cypher,

J., dissenting). The latter consideration ignores, however, the

evolution of Federal juvenile death penalty jurisprudence, which

involved judicial line drawing based on age without reliance on

a clearly legislatively defined age group. In Thompson v.

Oklahoma, 487 U.S. 815, 823, 838 (1988), a plurality of the

Supreme Court prohibited the imposition of the death penalty for

those under the age of sixteen at the time they committed their

12

conclude, as does the court, that the legislative line drawing

is more nuanced. The Legislature does not uniformly provide

eighteen through twenty year olds with the full benefits and

responsibilities of those twenty-one and older. Rather, the

Legislature recognizes that eighteen, nineteen, and twenty year

olds fall into a distinct category requiring special

consideration; they are permitted certain legal rights but not

others. See State House News Service (Sen. Sess.), June 28,

2018 (statement of Sen. Jason Lewis, chair of Joint Committee on

Public Health) (regarding tobacco purchasing age limit, "there

really is no single age of adulthood in our society"; [w]e make

decision[s] on a case-by-case basis depending on the activity").

For example, they are entitled to vote, serve on a jury or in

the military, and drive a car. See G. L. c. 51, § 1 (voting);

G. L. c. 234A, § 4 (jury); G. L. c. 90, § 8 (driving). See also

Requirements to enlist in the U.S. military, USA.gov,

offense. This decision stood in contrast to the many ways in

which the age of eighteen stood as a demarcation between

juveniles and adults.

The Court in Thompson, 487 U.S. at 838, had been asked to

"'draw a line' that would prohibit the execution of any person

who was under the age of [eighteen] at the time of the offense."

The Court limited its decision, however, to "the case before" it

and so drew the line at sixteen. In 2005, in Roper, 543 U.S. at

570-571, the Court took the opportunity to extend Thompson to

protect all juveniles -- those up to age eighteen -- from the

imposition of the death penalty. In both instances, the

judiciary -- not the Legislature -- extended these protections.

For us to do the same would not, therefore, be unprecedented.

13

https://www.usa.gov/military-requirements

[https://perma.cc/Y9MG-HWG4] (beginning at age seventeen). But

they cannot purchase and sell alcohol or tobacco, serve as a

State police officer, gamble, or even supervise drivers with

learner's permits. See G. L. c. 138, § 34 (alcohol); G. L.

c. 270, § 6 (tobacco); G. L. c. 31, § 58 (municipal police

officer); G. L. c. 22C, § 10 (State police officer); G. L.

c. 23K, § 43 (gambling); G. L. c. 90, § 8B (learner's permits).

They are also excluded from purchasing marijuana by a ballot

initiative, demonstrating that the public recognizes a similar

distinction. G. L. c. 94G, § 7 (a). Their rights regarding

firearms are also more limited than those twenty-one and over.

G. L. c. 140, § 131 (d) (iv) (license to carry large capacity

firearm restricted to those twenty-one and over).

I thus emphasize that legal rights from which eighteen

through twenty year olds are excluded appear to implicate and

reflect a legislative concern about the very characteristics

that are at issue in this case: "a lack of maturity and an

underdeveloped sense of responsibility, leading to recklessness,

impulsivity, and heedless risk-taking" and a greater

"vulnerab[ility] . . . to negative influences and outside

pressures, including from their family and peers" (quotations

and citations omitted). Diatchenko I, 466 Mass. at 660.

Senator Patricia Jehlen, the author of an amendment to the

14

expanded gaming bill that prohibited marketing to individuals

under twenty-one, stated: "The bill itself says that casinos

may not allow people under the age of [twenty-one]. . . .

Current Massachusetts law says you can't buy alcohol if you're

under [twenty-one]. I think that these are consistent that

people's brains have not matured by the time they're

[eighteen]." State House News Service (Sen. Sess.), Oct. 11,

2011. Likewise, the legislative history regarding increasing

the age for tobacco consumption to twenty-one shows that the

Legislature was concerned about the underdeveloped brains of

young people, including those above eighteen. See State House

News Service (Sen. Sess.), June 28, 2018 (statement of Sen.

Jason Lewis) ("Our young people are particularly

susceptible. . . . [Nicotine] has harmful health impacts on the

developing brain. . . . It helps [to] get tobacco products out

of high school social networks"); Press Release, Senate Passes

Jason Lewis Bill to Protect Youth from the Health Risks of

Tobacco and Nicotine Addiction (June 30, 2018),

https://senatorjasonlewis.com/2018/06/30/tobacco-21

[https://perma.cc/6MQM-QHXQ] (quoting Sen. President Harriette

L. Chandler, "This legislation protects young adults whose minds

and bodies are still developing . . ."). See also Governor's

Legislative Files, House Bill No. 4218, "An Act increasing the

minimum age for appointment as a police officer," Bill Summary

15

(2003) ("Advocates of this legislation suggest increasing the

minimum age for appointment for the position of police officer

will ensure that individuals taking on the responsibilities

associated with modern policing posses[s] the requisite life

skills and maturity").7

The criminal justice system also reflects special

consideration for this age group, again reflecting the special

characteristics of eighteen through twenty year olds. For

example, the Legislature has authorized the Department of Youth

Services to maintain custody of young people adjudicated to be

youthful offenders up to age twenty-one. G. L. c. 119, § 58.

Likewise, the Massachusetts Sentencing Guidelines have

instructed judges to consider the developmental characteristics

of eighteen through twenty year olds even when they have been

tried as adults. The Legislature has also, in its recent

comprehensive criminal justice reform, authorized the State and

7 Federal legislative history of the highway funding law

that led Massachusetts to raise the drinking age to twenty-one

discussed similar concerns. See Hearing before Subcommittee on

Surface Transportation of the United States Senate Committee on

Commerce, Science, and Transportation on Oversight of the

National Highway Traffic Safety Administration (Sept. 13, 1983),

reprinted in Legislative History of the Surface Transportation

Assistance Act of 1982 Amendments (1984) (statement of Robert S.

Vinetz, M.D.) (younger drivers' high rate of motor vehicle

accidents due to "especially deadly combination of being new and

inexperienced drivers, of having the tendency toward increased

risk-taking, of having an exaggerated belief in their own

invulnerability and in experimenting with alcohol and drugs").

16

county prison systems to "establish young adult correctional

units" with "targeted interventions, age appropriate

programming[,] and a greater degree of individual attention" for

those within this age group and also extended such consideration

to those as old as twenty-four, G. L. c. 127, § 48B. In sum,

the Legislature has recognized that eighteen through twenty year

olds are a distinct category requiring special consideration, at

least regarding legal rights that implicate risky, impulsive,

and potentially dangerous behavior and peer pressure -- the very

characteristics at issue in this case.

Given this legislative recognition of the need for

differential treatment of eighteen through twenty year olds in

such contexts, and the science and fact finding in this case,

which equates eighteen through twenty year olds to juveniles on

the relevant three characteristics that rendered juveniles less

culpable for their crimes, more capable of change, and thus

entitled to the possibility of parole in Diatchenko I, 466 Mass.

at 660, I conclude that eighteen through twenty year olds should

likewise be entitled to State constitutional protection from

life sentences without the possibility of parole. As in

Diatchenko I, we should not defer to the Legislature when it

recognizes the distinctive characteristics of the eighteen

through twenty year old defendants at issue and treats them

differently from those twenty-one and over in many ways, but

17

then disregards those differences for our most severe criminal

punishments. Upholding such sentences means that we disregard

the best science and continue to impose the most severe penalty

on a distinct legal category of individuals that we know are

less culpable and more capable of change.8

For all these reasons, this court in Diatchenko I, 466

Mass. at 671, declared the statute unconstitutional as applied

to a certain age group. Deference to the Legislature's

determination of a punishment that we, in Diatchenko, analogized

to the death penalty is different from ordinary deference. To

determine whether such a punishment is cruel or unusual is a

critical function of this court, and one that the court has

exercised with particular vigilance despite the objections of

dissenting justices calling for greater deference to the

Legislature. See id. at 672. See also, e.g., Commonwealth v.

Colon-Cruz, 393 Mass. 150, 181 (1984) (Wilkins, J., dissenting);

8 I also concur with the court's decision to limit this

relief to those under twenty-one. Unlike eighteen to twenty

year olds, those twenty-one and over have been considered by the

Legislature to have the full benefits and responsibilities of

adults. I consider the Legislature's recognition of the need

for differential treatment of those eighteen to twenty in a

variety of other contexts when the legal rights in question

implicate the same distinctive characteristics at issue in this

case to be an important component of the analysis. That

legislative recognition is absent when we consider those twenty-

one and over. It is the convergence of law and science, not

just science alone, that governs the art. 26 analysis here.

18

id. (Nolan, J., dissenting); District Attorney for Suffolk Dist.

v. Watson, 381 Mass. 648, 687 (1980) (Quirico, J., dissenting).9

c. The role of the tripartite analysis in Diatchenko I.

Another exceptional aspect of the Diatchenko I decision is the

legal authority to which this court turned for guidance and

support. We did not expressly employ the tripartite analysis

from Commonwealth v. Jackson, 369 Mass. 904, 910, 913 (1976),

and Cepulonis v. Commonwealth, 384 Mass. 495, 497-498 (1981)

(considering "the penalties prescribed for the same offense in

other jurisdictions"), and therefore tie our decision to how

most other States treated like offenders by applying the third

step of that analysis. We did not even compare ourselves to

other States or express concern that we were providing greater

protection than those other States. Again, this is a critical

and distinctive aspect of Diatchenko I. Instead, relying on our

own State Constitution, a legislatively defined category, which

in that case was juveniles, and comprehensive fact finding

grounded in science, to ensure the objectivity and integrity of

our decision-making process, we broke new ground in this

landmark decision, like other seminal State constitutional

9 The deference recommended here has similarities to those

dissents. See, e.g., Colon-Cruz, 393 Mass. at 184-185 (Nolan,

J., dissenting). It is important to remember that Diatchenko I,

466 Mass. at 670, made the comparison between life without the

possibility of parole and the death penalty. This is another

critical aspect of Diatchenko I that we cannot ignore.

19

decisions we have issued.10 Compare Goodridge v. Department of

Pub. Health, 440 Mass. 309, 312, 339 n.31 (2003) (recognizing

that "our decision marks a change in the history of our marriage

law" while noting only three other States' courts had taken

affirmative steps to recognize same-sex marriage under their

Constitutions while Federal government had not); Watson, 381

Mass. at 650, 662 (striking down death penalty for violating

art. 26 because it was "unacceptably cruel under contemporary

standards of decency" despite lack of "unanimity of public

opinion" as it was "administered with unconstitutional

arbitrariness and discrimination").

For further support when deciding Diatchenko I, 466 Mass.

at 285 n.16, we turned to the author of our State Constitution,

John Adams, and even widened our perspective internationally.

We noted Adams's reminder that "we belong to an international

community that tinkers toward a more perfect government by

learning from the successes and failures of our own structures

and those of other nations." Id., citing J. Adams, Preface, A

Defence of the Constitutions of Government of the United States

of America (1797). We also referenced the United Nations

10I note that Diatchenko I has been cited in 127 decisions,

including fifty out-of-State cases. See Goldstein, One of One:

Justice Gants and Lessons from the Keo Case, 62 B.C. L. Rev.

2827, 2828 (2021) (referring to Diatchenko I as "momentous

decision[]").

20

Convention of the Rights of the Child, which bans life in prison

without parole for juveniles. Diatchenko I, supra.

Given the distinct letter and spirit of Diatchenko I

described in detail supra, and the undisputed factual findings

here demonstrating that eighteen through twenty year olds share

the same relevant characteristics regarding diminished

culpability and heightened capacity for change as juveniles, I

conclude that we should extend the very same protections

provided to Gregory Diatchenko to eighteen through twenty year

olds. I discern no basis for distinguishing them given the

distinct reasoning developed in Diatchenko I. A sentence of

life in prison without parole eligibility review for those up to

age twenty-one -- individuals with diminished culpability and a

heightened capacity for change -- is no less cruel or unusual

than it is for those up to age eighteen. Cf. Diatchenko I, 466

Mass. at 670-671. Thus, we should have been "obliged to declare

part of [this statute] unconstitutional," id. at 672, and have

provided these eighteen through twenty year old homicide

offenders with "a meaningful opportunity for release on parole,"

should they "demonstrate[] maturity and rehabilitation," so that

their "life sentence [is] constitutionally proportionate,"

Diatchenko II, 471 Mass. at 29-30.

d. Limited remedy. We also, as in Diatchenko I, 466 Mass.

at 671, need only hold a very specific application of the

21

statute unconstitutional. As we explained in Diatchenko I, "the

unconstitutionality of this punishment arises not from the

imposition of a sentence of life in prison, but from the

absolute denial of any possibility of parole" for a class of

offenders who a trial judge cannot reliably determine to be

irretrievably depraved at the time of sentencing. See id. Once

they have a chance to mature, however, that decision, as well as

the other factors relevant to parole, would and should be made

by a parole board. That decision would also be made after many

years of imprisonment. See id. at 674. Under current law,

those under age eighteen who are convicted of murder in the

first degree are eligible for parole only after serving from

twenty-five to thirty years for murder convicted with deliberate

premeditation and thirty if the murder was committed with

extreme atrocity or cruelty. G. L. c. 279, § 24. I would

extend the same opportunity to those older than eighteen but

under the age of twenty-one. Essentially, the legislative

regime imposed for juvenile murderers would be extended to

eighteen to twenty year olds without further changes in the

statutory scheme.

The possibility of such reformative change after a lengthy

period of incarceration has also been demonstrated since we

decided Diatchenko I. Of the juvenile offenders who were

serving mandatory life sentences without parole at the time of

22

the Diatchenko I decision and have since received parole

hearings, seventy-four percent have been granted parole. As

Diatchenko I and its aftermath have demonstrated, the

possibility of redemption exists for the young, even those who

have committed the most horrible crimes, after they have spent

many years in prison maturing and taking responsibility for the

terrible deaths that they caused in their youth.

For all these reasons, I conclude that a sentence of life

without the possibility of parole for eighteen through twenty

year olds constitutes cruel or unusual punishment under art. 26

of our Declaration of Rights. That applies to both

discretionary as well as mandatory life sentences without the

possibility of parole for those eighteen through twenty years of

age.

WENDLANDT, J. (concurring, with whom Gaziano, J., joins).

The determination whether the Commonwealth's harshest punishment

is so disproportionate to the offender as to shock the conscious

is neither one we abdicate to the Legislature, as marshalled by

the dissent, nor one we rest on the shoulders of scientists and

social scientists. I write to clarify what should be pellucid:

it is our constitutional duty to ensure prescribed punishments

pass constitutional muster, and nothing in art. 30 of the

Massachusetts Declaration of Rights prevents us from doing so.

To be faithful to the enormity of this charge, we must undertake

a comprehensive review of our statutes, the scientific record,

our collective experiences, and common sense.

Having examined these sources, I conclude that they confirm

what any parent of adult children can tell you: a child does

not go to bed on the eve of her eighteenth birthday and awaken

characterized by a lessened "transient rashness, proclivity for

risk, and inability to assess consequences." Miller v. Alabama,

567 U.S. 460, 472 (2012). In recognition of this indisputable

fact, society does not treat the transition from childhood to

adulthood as a binary act accomplished at age eighteen; becoming

an adult is much more fluid, with development continuing long

after a child's eighteenth birthday. In the ways that matter

for the Commonwealth's harshest punishment, young adults of the

ages of eighteen, nineteen, and twenty share key characteristics

2

with their under-eighteen year old peers; they "have diminished

culpability and greater prospects for reform" than older adults

and "are less deserving of the most severe punishments." See

id. at 471, quoting Graham v. Florida, 560 U.S. 48, 68 (2010).

For this reason, condemning a person in the process of "growing

up" to die in prison on the basis that she falls on the "wrong"

side of an arbitrary line drawn at age eighteen is inconsistent

with "the evolving standards of decency that mark the progress

of a maturing society" (citation omitted). Graham, supra at 58.

Accordingly, I agree with the court that imposition of life

without the possibility of parole on young adults ages eighteen,

nineteen, and twenty is unconstitutional.

1. Legislature's treatment of young adults. Undoubtedly,

the first source in the determination of our contemporary

standards of decency that define the bounds of cruel punishment

is legislative enactments. See Good v. Commissioner of

Correction, 417 Mass. 329, 335 (1994) ("In divining contemporary

standards of decency, we may look to State statutes and

regulations, which reflect the public attitude as to what those

standards are"). See also Graham, 560 U.S. at 61, quoting Roper

v. Simmons, 543 U.S. 551, 563 (2005) ("The Court first considers

'objective indicia of society's standards, as expressed in

legislative enactments and state practice' . . ."); Atkins v.

Virginia, 536 U.S. 304, 312 (2002) ("the clearest and most

3

reliable objective evidence of contemporary values is the

legislation enacted by the country's legislatures" [quotation

and citation omitted]).1

Our statutes reflect legislative recognition that maturity

is a gradual endeavor,2 and that while age eighteen is a

milestone, society does not view it as the end of the

metamorphosis toward adulthood. As the court and Justice Kafker

thoroughly catalogue, for many activities considered by society

to require greater care, less risk taking, and more resilience

1 In concluding that a mandatory sentence of life in prison

without the possibility of parole violated the Eighth Amendment

to the United States Constitution when imposed on juvenile

nonhomicide offenders, the United States Supreme Court

considered that, although thirty-seven State legislatures

permitted the sentence, only eleven States imposed the sentence

in practice, and vanishingly few juvenile offenders actually

received it. See Graham, 560 U.S. at 62-67 (only approximately

123 juvenile nonhomicide offenders were serving sentences of

life without parole; seventy-seven of those offenders were in

Florida, and the remainder were in just ten States). See also

Atkins, 536 U.S. at 316 (considering that "even in those States

that allow the execution of [offenders with intellectual

disabilities], the practice is uncommon," in concluding that "a

national consensus has developed" against executing such

individuals). Because the sentence is mandatory for all adults

over the age of eighteen in Massachusetts, see G. L. c. 265,

§ 2 (a), we cannot look to sentencing practices as they pertain

to young adult offenders.

2 As Justice Cypher notes, post at , at a point earlier

than the age of eighteen, the Legislature has recognized that

one commences the transition from being a child to being an

adult and therefore awards certain freedoms to these young

people before they turn eighteen years old. For example, young

women, as early as age sixteen, can obtain an abortion without

parental consent. See G. L. c. 112, § 12R.

4

to peer pressure, the Legislature continues to treat young

adults over the age of eighteen like juveniles. To engage in

these activities legally, young adults must wait until they are

twenty-one.

This special treatment exemplifies the Legislature's

acknowledgment of two facts: first, that the impetuousness of

youth, the proclivity to risk taking, and the susceptibility to

peer pressure are not attributes exclusive to those under the

age of eighteen, and instead continue into young adulthood; and

second, that these attributes are not fixed, but generally fade

over time because young adults, like juveniles, are

characterized by a malleability of character.3

2. Science and social science. Of course, consideration

of legislation is the beginning; it is not the end of our

analysis under art. 26 of the Massachusetts Declaration of

Rights. To be faithful to our responsibility to protect

individuals from cruel or unusual punishment meted out by the

3 Private institutions also recognize that young adults are

not ready for all the responsibilities of adulthood. See, e.g.,

K.U. Lindell & K.L. Goodjoint, Juvenile Law Center, Rethinking

Justice for Emerging Adults: Spotlight on the Great Lakes

Region, at 12 (2020) ("while not a statutory restriction, most

car rental companies limit rentals to individuals under age

[twenty-five], recognizing the increased risk posed by this age

group"). See also Metz, How Age and Gender Affect Car Insurance

Rates, Forbes Advisor (updated Aug. 17, 2023), https://www

.forbes.com/advisor/car-insurance/rates-age-and-gender [https:

//perma.cc/LB8G-PHEG] ("The high car insurance rates that young

drivers pay start to go down at age [twenty-five]").

5

State, we cannot be blind to the truths that the scientific

sources with which we have been presented show.4

Our experiment with scientific fact finding on the topic of

adult brain development validates the graduated treatment of

young persons reflected in our statutes. The court's careful

review of this record is undisputed. In brief, it shows that

neuroscientists see in their magnetic resonance imaging (MRI)

scans corroboration for that which we experience in life; the

brain characteristics of persons even years older than eighteen

mirror those of persons under eighteen. The brain generally

continues to develop through the mid-twenties. Until some ill-

defined point in the third decade of life, adults, especially

4 See, e.g., Miller, 567 U.S. at 471 (determination that

life in prison without possibility of parole for juveniles

violates Eighth Amendment rested "not only on common sense -- on

what 'any parent knows' -- but on science and social science as

well" [citation omitted]); Graham, 560 U.S. at 68 (considering

"developments in psychology and brain science" in Eighth

Amendment proportionality analysis as to life in prison without

possibility of parole for juveniles convicted of nonhomicide

offenses); Roper v. Simmons, 543 U.S. 551, 569 (2005)

(considering what "any parent knows" and what "scientific and

sociological studies . . . tend to confirm" to conclude death

penalty for juveniles violates Eighth Amendment); Diatchenko v.

District Attorney for the Suffolk Dist., 466 Mass. 655, 669

(2013), S.C., 471 Mass. 12 (2015) (concluding imposition of

sentence of life in prison without possibility of parole for

juveniles, even after individualized hearing, violates art. 26

of Massachusetts Declaration of Rights "[g]iven current

scientific research on adolescent brain development").

6

men,5 generally are more impulsive and their brains are more

plastic than those of older adults.6

3. Collective experience and common sense. Significantly,

while the findings based on current technological advances in

brain science show substantial similarities between juveniles

and young adults, we do not check our common sense at the

laboratory door. Our statutes, experiences, and common sense

tell us that there is no magic switch to the process of growing

up, and that fact, now buttressed by neuroscientific data and

informed by social science studies, must be weighed in the

exercise of our duty to determine whether punishment is cruel or

unusual. See Matter of the Personal Restraint of Monschke, 197

Wash. 2d 305, 306 (2021) ("Modern social science, our precedent,

5 See L. Brizendine, The Female Brain 44 (2006) (finding

that female brain "matures two or three years earlier than the

male brain"). See also Cauffman & Steinberg, (Im)maturity of

Judgment in Adolescence: Why Adolescents May Be Less Culpable

Than Adults, 18 Behav. Sci. & L. 741, 753 (2000) (finding that

"females exhibit greater psychosocial maturity than males").

6 Scientific studies report brain maturation at different

ages: sometimes at the age of twenty-one, sometimes at twenty-

two, sometimes at twenty-three or twenty-five, and sometimes in

the middle to late twenties. Moreover, studies report that

certain aspects of brain development, such as susceptibility to

peer pressure and impulse control, also appear to mature at

different rates.

7

and a long history of arbitrary line drawing have all shown that

no clear line exists between childhood and adulthood").7

The scientific snapshot in this case confirms that which is

apparent in our laws and in our treatment of this age cohort

more generally –- namely, that in the ways that matter for

criminal sentencing, young adults are similar to juveniles.

Like juveniles, young adults have "an underdeveloped sense of

responsibility, leading to recklessness, impulsivity, and

heedless risk-taking"; they are more vulnerable to peer

pressure; and their "character is not as well formed as an

adult's . . . and [their] actions [are] less likely to be

evidence of irretrievabl[e] deprav[ity]" (quotations omitted).

Diatchenko v. District Attorney for the Suffolk Dist., 466 Mass.

7 The parties in this case ask us to consider the

constitutionality of the punishment of life in prison without

the possibility of parole when it is imposed on defendants aged

eighteen, nineteen, and twenty. That the scientific record is

not precise as to where the line should be drawn, see note 6,

supra, should come as no surprise given our collective

experiences showing that, while some generalizations may be

drawn, in the end "growing up" is an individualized endeavor.

This does not mean that "we may as well give up and let the

[L]egislature draw its arbitrary lines." Matter of the Personal

Restraint of Monschke, 197 Wash. 2d at 323. At the least, in

response to the only question with which we have been presented

in this case, I conclude that drawing a fixed line at the age of

eighteen, thereby leaving young adults aged eighteen, nineteen,

and twenty to the punishment, is not supported by our statutes,

the scientific data and social science, our collective

experiences, or common sense.

8

655, 660 (2013) (Diatchenko I), S.C., 471 Mass. 12 (2015),

quoting Miller, 567 U.S. at 471.

Relying on these hallmarks of youth, the United States

Supreme Court concluded that mandatory life in prison without

the possibility of parole is a cruel punishment when applied to

juveniles. Miller, 567 U.S. at 489. And, in view of these

characteristics of juveniles, we separately concluded that art.

26 prohibits the mandatory imposition of this punishment. See

Diatchenko I, 466 Mass. at 667. We also concluded that art. 26

offers greater protections to our children than are available

under the Eighth Amendment to the United States Constitution.

Specifically, we concluded that, in view of the hallmarks of

youth that characterize juveniles, art. 26's greater protection

prohibits so-called Miller hearings to determine whether, on an

individualized consideration of a particular juvenile homicide

defendant's circumstances, the sentence of life without the

possibility of parole was proportionate. Id. at 669-671.

Because the aforementioned review of our statutes, the

scientific data, collective experiences, and common sense

confirms that these same qualities characterize young adults, it

necessarily follows that art. 26 prohibits the punishment as

applied to this cohort. For these reasons, I concur.

LOWY, J. (dissenting, with whom Cypher and Georges, JJ.,

join). I cannot say that society, through its elected

officials, may not express its revulsion of the crime of murder

in the first degree by imposing a punishment of life without the

possibility of parole on adults without offending our

Declaration of Rights. Therefore, I respectfully dissent.

The power to "define a crime and ordain its punishment" is

an exclusively legislative function, and "in judging legislative

determinations of crimes and punishments, we exercise our powers

of review with great caution" (citation omitted). Opinions of

the Justices, 378 Mass. 822, 830 & n.7 (1979). For the crime of

murder in the first degree, the Legislature has deemed the

mandatory imposition of life without the possibility of parole

to be the appropriate punishment for adults eighteen and older

convicted of this offense. While we have an obligation to

intervene when the Legislature acts unconstitutionally, unless

the punishment the Legislature imposes is "so disproportionate"

that it "shocks the conscience and offends fundamental notions

of human dignity" (citation omitted), Cepulonis v. Commonwealth,

384 Mass. 495, 497 (1981), we must exercise restraint and uphold

it, see art. 26 of the Massachusetts Declaration of Rights;

Eighth Amendment to the United States Constitution.

In this case, the defendant argues that, in light of recent

advances in scientific brain research concerning young adults,

2

the line between those who may constitutionally be subject to

the mandatory imposition of life without the possibility of

parole and those who may not should be at the age of twenty-one,

rather than at the age of eighteen. Our analysis for

determining whether a punishment is constitutionally

disproportionate considers whether the punishment is cruel or

unusual in light of "contemporary standard[s] of decency"

(citation omitted). Libby v. Commissioner of Correction, 385

Mass. 421, 431 (1982). We look to statutes enacted by the

Legislature, along with regulations, as the best objective

evidence for divining contemporary values. See Good v.

Commissioner of Correction, 417 Mass. 329, 335 (1994). Doing so

is not affording uncritical deference to the Legislature's

choice of punishment, but rather it is a direct application of

our constitutional doctrine that looks to legislation to derive

contemporary values. Indeed, "legislatures, not courts, are

constituted to respond to the will and consequently the moral

values of the people." See Gregg v. Georgia, 428 U.S. 153, 175

(1976), quoting Furman v. Georgia, 408 U.S. 238, 383 (1972)

(Burger, C.J., dissenting). Consequently, to determine whether

this mandatory sentence violates art. 26, we must look to

legislative evidence to determine whether the line that the

defendant urges us to draw at the age of twenty-one is one that

is consistent with society's contemporary values.

3

Contrary to the court's conclusion that it is, the

objective sources of contemporary standards of decency in the

Commonwealth simply do not reflect a public consensus that life

without parole, when imposed mandatorily on individuals from

eighteen to twenty who have been convicted of murder in the

first degree, is cruel or unusual. Rather, the Legislature has

definitively drawn the line between childhood and adulthood at

eighteen, and objective indicia of contemporary standards of

decency in the Commonwealth demonstrate support for, rather than

objection to, treating individuals within this age range as

adults in our criminal justice system when they commit the crime

of murder in the first degree.

Where individuals from eighteen to twenty-one have been

deemed adults by the Legislature and society, precedent relating

to the sentencing of juveniles -- who are "constitutionally

different from adults for purposes of sentencing" -- is inapt.

Miller v. Alabama, 567 U.S. 460, 471 (2012). Thus, our decision

in Diatchenko v. District Attorney for the Suffolk Dist., 466

Mass. 655, 669 (2013) (Diatchenko I), S.C., 471 Mass. 12 (2015),

cannot resolve the question of the proportionality of the

mandatory sentence challenged in this case. In Diatchenko I, we

did not purport to draw a line between juveniles and adults.

Our focus, rather, was on a category of individuals --

predefined by the Legislature -- and our inquiry as to that

4

category was precise and limited. See id. at 659 n.8. Where

the United States Supreme Court concluded in Miller, supra at

469, that imposing mandatory life without parole on juveniles

violates the Eighth Amendment, we were addressing only the

discretionary imposition of such a sentence, i.e., whether,

under art. 26, an individualized assessment of a juvenile

offender could ever result in a determination that "a sentence

of life without parole should be imposed on a juvenile homicide

offender." Diatchenko I, supra at 670. We concluded that art.

26 did not permit such an individualized assessment at the time

of sentencing.

As it relates to the court's conclusion that this mandatory

sentence is categorically unconstitutional, scientific brain

research, untethered to societal views expressed through

legislation, can neither draw the line between childhood and

adulthood nor manufacture a new category of individuals entitled

to distinct constitutional treatment for purposes of determining

whether a sentence is constitutionally disproportionate under

art. 26. And, even if it could, science does not definitively

place the line of brain maturation at twenty-one, but rather

suggests that it extends into the mid-twenties. Perhaps nothing

speaks louder to the flaws in the court's holding that this

mandatory sentence violates art. 26 than the court having

crafted a line that ends at age twenty-one, thereby engaging in

5

legislative line drawing inconsistent with the science upon

which it relies. Where punishment is involved, we must look to

society and the Legislature to determine where the appropriate

line is and where it should be.

Our assessment under art. 26 is not whether the mandatory

imposition of life without the possibility of parole for

individuals from eighteen to twenty-one is, in our view, wise,

prudent, or even best for society. Our inquiry is limited to

whether the punishment, chosen by the Legislature, is so

disproportionate that it reaches the level of cruel or unusual.

See Diatchenko I, 466 Mass. at 669. Because, under our

contemporary standards of decency and precedent, the mandatory

imposition of life without the possibility of parole on adults

who commit murder in the first degree when they are from

eighteen to twenty-one is not "so disproportionate" that "it

'shocks the conscience and offends fundamental notions of human

dignity,'" id., quoting Cepulonis, 384 Mass. at 497, the

sentence does not violate art. 26's proscription against cruel

or unusual punishment. It therefore must be upheld.

Background. On September 25, 2011, fourteen year old

Kimoni Elliott was visiting his schoolmate and friend, Jaivon

Blake, who lived in the area of Geneva Avenue and Everton Street

in the Dorchester section of Boston. Elliott lived on Everton

Street in Dorchester. That afternoon, Elliott was standing

6

outside a convenience store on Geneva Avenue near Levant Street

in Dorchester, an area controlled by the "Flatline" gang.

Elliott was looking for somebody old enough to purchase rolling

papers for marijuana cigarettes for him. The defendant,

eighteen year old Sheldon Mattis, was a member of the Flatline

gang. He had been playing football on Levant Street with some

other people when he observed Elliott walking toward the

convenience store. The defendant approached Elliott and offered

to purchase rolling papers for him, and after doing so, the

defendant asked Elliott where he was from. When Elliott

responded, "Everton," the defendant assumed that Elliott was a

member of a rival gang.

Elliott and Blake then met in a nearby parking lot and

started walking up Geneva Avenue towards Blake's home while the

defendant returned quickly towards Levant Street. Minutes

later, the defendant met with seventeen year old Nyasani Watt on

the corner of Levant Street and Geneva Avenue. He turned his

bicycle over to Watt and handed Watt his gun. The defendant

then pointed out Elliott and Blake to Watt, patted him on the

back, and told him that Watt "needed to go handle that." Watt

complied. Watt approached the victims from behind while on the

bicycle and fired multiple shots at them. Blake fell to the

ground and later died from his injuries. Elliott, despite being

shot in the neck and arm, survived.

7

Discussion. 1. Judicial review of punishment designated

by the Legislature. "[T]he power of punishment is vested in the

legislative, not in the judicial department. It is the

[L]egislature, not the [c]ourt, which is to define a crime and

ordain its punishment." Opinions of the Justices, 378 Mass. at

830 n.7, quoting United States v. Wiltberger, 18 U.S. (5 Wheat.)

76, 95 (1820). Entrusted with this authority, "[t]he

Legislature has great latitude to determine what conduct should

be regarded as criminal and to prescribe penalties to vindicate

the legitimate interests of society." Commonwealth v. Jackson,

369 Mass. 904, 909 (1976). The Legislature's judgment in this

area is thus "to be accorded due respect," Opinions of the

Justices, supra at 830, and it is subject only to the

constitutional limitations imposed by the Eighth Amendment and

art. 26, see Jackson, supra.

Article 26, which affords greater protections than the

Eighth Amendment, proscribes cruel or unusual punishment; the

"touchstone" of this proscription is proportionality.

Commonwealth v. Yat Fung Ng, 491 Mass. 247, 271 (2021). This

"flows from the basic 'precept of justice that punishment for

crime should be graduated and proportioned' to both the offender

and the offense." Diatchenko I, 466 Mass. at 669, quoting

Miller, 567 U.S. at 469. Our role as the judiciary is therefore

to determine whether the punishment designated by the

8

Legislature is "so disproportionate to the offense as to

constitute cruel [or] unusual punishment."1 Cepulonis, 384 Mass.

at 496.

"To reach the level of cruel [or] unusual, the punishment

must be so disproportionate to the crime that it 'shocks the

conscience and offends fundamental notions of human dignity.'"

Diatchenko I, 466 Mass. at 669, quoting Cepulonis, 384 Mass. at

497. In conducting this analysis, we consider "contemporary

standards of decency which mark the progress of society."

Diatchenko I, supra, quoting Good v. Commissioner of Correction,

417 Mass. 329, 335 (1994). "But in judging legislative

determinations of crimes and punishments, we exercise our powers

of review with great caution." Opinions of the Justices, 378

Mass. at 830. See Jackson, 369 Mass. at 909 ("It is thus with

restraint that we exercise our power of review to determine

whether the punishment before us exceeds the constitutional

limitations imposed by the Eighth Amendment and by art. 26").

"Therefore, in assessing a punishment selected by a

democratically elected [L]egislature against the constitutional

measure, we presume its validity." Gregg, 428 U.S. at 175. See

Jackson, 369 Mass. at 909, quoting Weems v. United States, 217

Article 26 prohibits the infliction of "cruel or unusual

1

punishments," while the Eighth Amendment proscribes "cruel and

unusual punishments."

9

U.S. 349, 379 (1910) ("The function of the [L]egislature is

primary, its exercises fortified by presumptions of right and

legality, and is not to be interfered with lightly, nor by any

judicial conception of their wisdom or propriety"). "[W]hile we

have an obligation to insure that constitutional bounds are not

overreached, we may not act as judges as we might as

legislators." Gregg, supra at 174-175. "We may not require the

[L]egislature to select the least severe penalty possible so

long as the penalty selected is not cruelly inhumane or

disproportionate to the crime involved. And a heavy burden

rests on those who would attack the judgment of the

representatives of the people." Id. at 175. Accordingly, "a

heavy burden is on the sentenced defendant to establish that the

punishment is disproportionate to the offense for which he was

convicted." Commonwealth v. Bianco, 390 Mass. 254, 260-261

(1983), quoting Commonwealth v. O'Neal, 369 Mass. 242, 248

(1975) (Tauro, C.J., concurring).

In concluding that the mandatory imposition of life

imprisonment without the possibility of parole for individuals

from eighteen to twenty-one who have been convicted of murder in

the first degree violates art. 26, the court considers

contemporary standards of decency and prior precedent. See ante

at . Rather than consider science as an independent factor

in assessing proportionality, the court, for the first time,

10

concludes that "current scientific consensus regarding the

characteristics of the class can help determine the contemporary

standards of decency pertaining to that class." Id. at .

The incorporation of science -– with which I agree -– into the

consideration of contemporary standards of decency in the

constitutional analysis of art. 26 risks diluting the value of

both science and contemporary standards of decency in analyzing

proportionality. To understand contemporary standards of

decency, we must look to "'objective indicia of society's

standards, as expressed in legislative enactments and state

practice[,]' to determine whether there is a national consensus

against the sentencing practice at issue." Graham v. Florida,

560 U.S. 48, 61 (2010), quoting Roper v. Simmons, 543 U.S. 551,

552 (2005). Science, no doubt, is a valuable source in

considering proportionality, as well as in assisting

legislatures in how best to line draw around sentencing.

But science and contemporary standards of decency, although

both vitally important, are distinct sources of information. It

is necessary to independently examine how elected officials and

States have chosen to express consensus on the proportionality

of punishment, themselves having had the opportunity to weigh

myriad factors, including scientific development, in their

decision-making processes. The judge's factual findings in July

2022 as to the brain development of emerging adults were well

11

supported, and indeed I embrace them. But the court's

incorporation of science into contemporary standards of decency

does not change the outcome of this case. Nothing about

mandatory life imprisonment without the possibility of parole

for individuals from eighteen to twenty-one who have been

convicted of the most heinous crime of murder in the first

degree -- either with deliberate premeditation, with extreme

atrocity or cruelty, or with actual malice in the commission or

attempted commission of a crime punishable with life

imprisonment -- offends contemporary standards of decency. See

Commonwealth v. Okoro, 471 Mass. 51, 61 (2015) ("art. 26

nevertheless 'draw[s] its meaning from the evolving standards of

decency that mark the progress of a maturing society,' such that

developments in the area of juvenile justice in judicial

opinions and legislative actions at the State, Federal, and

international levels help to inform our understanding of what

art. 26 protects" [citation omitted]).

Accordingly, I address contemporary standards of decency,

precedent, and science in turn.

2. Contemporary standards of decency. "Article 26 bars

punishments which are found to be cruel or unusual in light of

contemporary standards of decency which mark the progress of

society." Good, 417 Mass. at 335. The evaluation of

contemporary standards of decency to assess disproportionality

12

"should be informed by 'objective factors to the maximum

possible extent.'" Atkins v. Virginia, 536 U.S. 304, 312

(2002), quoting Harmelin v. Michigan, 501 U.S. 957, 1000 (1991)

(Kennedy, J., concurring in part and concurring in the

judgment). Proportionality "judgments should not be, or appear

to be, merely the subjective views of individual Justices,"

Rummel v. Estelle, 445 U.S. 263, 274 (1980), quoting Coker v.

Georgia, 433 U.S. 584, 592 (1977) (plurality opinion), and

therefore "courts should pay special attention to objective

factors deciding whether a practice violates 'the contemporary

standard of decency.'" Libby, 385 Mass. at 431, quoting Rhodes

v. Chapman, 452 U.S. 337, 347 (1981). See Coker, supra at 611

(Burger, C.J., dissenting), quoting Furman, 408 U.S. at 431

(Powell, J., dissenting) ("[W]here, as here, the language of the

applicable [constitutional] provision provides great leeway and

where the underlying social policies are felt to be of vital

importance, the temptation to read personal preference into the

Constitution is understandably great. It is too easy to

propound our subjective standards of wise policy under the

rubric of more or less universally held standards of decency").

"[T]he 'clearest and most reliable objective evidence of

contemporary values is the legislation enacted by the . . .

[L]egislature[].'" Atkins, 536 U.S. at 312, quoting Penry v.

Lynaugh, 492 U.S. 302, 331 (1989). See Gregg, 428 U.S. at 175,

13

quoting, Furman, 408 U.S. at 383 (Burger, C.J., dissenting)

("[I]n a democratic society legislatures, not courts, are

constituted to respond to the will and consequently the moral

values of the people"). Thus, "[i]n divining contemporary

standards of decency, we may look to State statutes and

regulations, which reflect the public attitude as to what those

standards are." Good, 417 Mass. at 335. In other words, our

doctrinal framework for interpreting the text looks, in part, to

legislative judgments for objective evidence of contemporary

values. When we infuse normative values into the open-ended

provisions of art. 26's proscription against "cruel or unusual

punishments," our doctrine protects against the great danger of

judges infusing their own values into their interpretation of

contemporary standards of decency by considering legislative

judgments as to crime and punishment.

Beginning generally with legislation relating to

individuals from eighteen to twenty-one, our Commonwealth

considers these individuals adults, and has done so

unequivocally for more than forty years. See G. L. c. 4, § 7,

Forty-eighth to Fifty-first, inserted by St. 1973, c. 925 ("In

construing statutes [in the Commonwealth] the following words

shall have the meanings herein given . . . : 'Minor' shall mean

any person under eighteen years of age. . . . 'Full age' shall

mean eighteen years of age or older. . . . 'Adult' shall mean

14

any person who has attained the age of eighteen. . . . 'Age of

majority' shall mean eighteen years of age"). Individuals in

this category have been granted rights in Massachusetts

generally associated with adulthood. See art. 3 of the

Amendments to the Constitution of the Commonwealth, as amended

through art. 100 of the Amendments (right to vote); G. L.

c. 234A, § 4 (serving on jury); G. L. c. 207, §§ 7, 24 (entering

marriage); G. L. c. 231, § 85O (entering contracts).2 This

includes the right to make decisions having potentially life-

altering effect. See Norwood Hosp. v. Munoz, 409 Mass. 116,

122-123 (1991) (common-law and State constitutional right for

competent adults to refuse medical treatment, even where

treatment may be lifesaving).

Nothing in the statutes that restrict certain activities to

individuals over the age of twenty-one alters or changes the age

at which the Legislature has determined adulthood begins.

Certainly none of the statutes on which the court or

2 See also Office of Attorney General, When You Turn 18,

https://www.mass.gov/doc/your-guide-to-understanding-your-

rights-responsibilities-and-how-to-protect-yourself-when-you-

turn-18/download#:~:text=You're%2018!,and%20responsibilities

%20of%20an%20adult [https://perma.cc/QU9M-YV72] ("You're 18! In

Massachusetts you've now reached the age of legal adulthood.

With this milestone, you have nearly all the legal rights and

responsibilities of an adult. Among your new rights are the

right to vote and serve on a jury, to marry, to enlist in the

military or choose medical care, and to be responsible for any

contracts you sign").

15

concurrences rely suggests that the activity restricted is

limited only to "adults."3 See G. L. c. 138, § 34 (must be

twenty-one years of age to purchase and sell alcoholic

beverages); G. L. c. 270, § 6 (must be twenty-one years of age

to purchase tobacco products), G. L. c. 140, § 131 (d) (iv)

(must be twenty-one years of age to obtain license to carry

handgun); G. L. c. 22C, § 10 (must be twenty-one years of age to

be State police officer); G. L. c. 31, § 58 (must be twenty-one

years of age to be municipal police officer); and G. L. c. 23K,

§ 25 (h) (must be twenty-one years of age to gamble or be in

gambling area).

Article 26's requirements, however, are not adjudged by an

amorphous consideration of contemporary standards of decency as

they relate to age generally. Those contemporary standards of

decency must relate to some extent to the crime and punishment

at hand. After all, the relevant inquiry is whether the

3 Relying on statutes that restrict or permit activities to

persons of a certain age is not an appropriate measure to

determine when society deems a person an adult, particularly

where those statutes do not expressly limit the activity to

"adults." For instance, several statutes restrict certain

activities to those over the age of sixteen, such as operating a

motor vehicle, G. L. c. 90, § 10, and working without a permit,

G. L. c. 149, § 90, but we would not consider those statutes as

evidence that a sixteen year old is an adult. Instead, the best

and most reliable evidence of when society considers the

beginning of adulthood is the point at which the Legislature

defines a person as an adult -- eighteen. See G. L. c. 4, § 7,

Fiftieth.

16

challenged punishment is "cruel or unusual in light of

contemporary standards of decency." Good, 417 Mass. at 335.

In this context, not only has the Legislature expressly provided

that individuals eighteen and older are adults in our

Commonwealth, see G. L. c. 4, § 7, Fiftieth, but it also has

determined that these individuals are responsible as adults in

our criminal justice system, see G. L. c. 119, §§ 52-54

(proceedings against children under eighteen in Juvenile Court

not deemed criminal). This has included the mandatory

imposition of life without parole on individuals over eighteen

convicted of murder in the first degree. See G. L. c. 265, § 2.

If the Legislature, responding to the will of the people, wished

to extend the age that individuals are treated as juveniles,

rather than adults, in our court system, it knows how to do so.

See St. 2013, c. 84, §§ 25, 26, amending G. L. c. 119, § 74

(expanding juvenile jurisdiction to eighteen year olds).

Statutes and regulations throughout our Commonwealth do not

even suggest that contemporary standards of decency consider the

mandatory imposition of life without parole on adults from

eighteen to twenty-one to be cruel or unusual punishment for the

crime of murder in the first degree. The sources upon which the

court relies do not address contemporary common views,

particularly as they relate to offenders within this age range

charged with murder.

17

To begin, the court's reliance on a statute authorizing

youthful offenders to be committed to the Department of Youth

Services until the age of twenty-one is misplaced. That the

Legislature has designated, among several permissible

punishments for a child under the age of eighteen who has been

adjudicated a youthful offender, commitment to the Department of

Youth Services until the age of twenty-one is not relevant to

society's views of punishment for those who commit crimes while

eighteen or over, let alone the crime of murder. See G. L.

c. 119, §§ 54, 58. Rather, this is a sentencing scheme limited

to juveniles. Moreover, the court relies on a task force formed

by the Legislature on emerging adults to suggest that

contemporary standards favor providing distinct treatment to

those from eighteen to twenty-one in our criminal legal system.

See ante at note 22. However, the task force defined "emerging

adults" as individuals from ages eighteen to twenty-four, not

twenty-one, and in its report proposing certain changes to our

system applicable to this age group, it, importantly, excluded

from those changes the crime of murder. Specifically, the task

force found, as the science demonstrates, see infra, that

individuals ages eighteen to twenty-four, "while possessing the

cognitive capacity to make deliberative decisions, are more

likely to be more impulsive, less future-oriented, more unstable

in emotionally charged settings, and more susceptible to peer

18

and other outside influences." Emerging Adults in the

Massachusetts Criminal Justice System: Report of the Task Force

on Emerging Adults in the Criminal Justice System (Feb. 26,

2020), 2020 Senate Doc. No. 2840, at 6-7. Even so, in making

its proposals for consideration by the Legislature, the task

force provided several options for changes to our current system

but excluded from all these proposals individuals of this age

group charged with the crime of murder. Some examples included

extending the juvenile justice system, except in murder cases;

creating a "young adult offender" category, excluding high-level

offenses such as murder; providing judges with discretion to

refer certain cases to juvenile court, excluding high-level

offenses such as murder; and creating an "emerging adult" court

session, excluding individuals charged with the crime of murder.

Id. at 7, 9-10.

Furthermore, although, as the defendant and Justice

Kafker's concurrence point out, the Advisory Sentencing

Guidelines (guidelines) recommended by the Massachusetts

Sentencing Commission in 2017 provide that research concerning

the brain development of emerging adults, which it defines as

individuals "up to and including age [twenty-one]" (emphasis

added), may be considered at sentencing, the guidelines are

intended to assist with discretionary sentencing and are

inapplicable to mandatory sentencing provisions such as those

19

designated for the crime of murder in the first degree. See

Massachusetts Sentencing Commission, Advisory Sentencing

Guidelines 4, 7-8 (Nov. 2017) ("In making these Sentencing

Guidelines advisory, rather than voluntary, the Commission

intends to provide a starting point for consideration, and not a

constraint on judicial discretion in fashioning an appropriate

sentence. . . . [T]he Commission has no authority to abolish

minimum mandatory sentences or to change other statutory penalty

provisions"). More importantly, the guidelines do not reflect

public consensus, nor do they purport to do so.4 The guidelines

were never enacted by the Legislature, and thus have not taken

effect. See G. L. c. 211E, § 3 (a) (1) ("The commission . . .

shall recommend sentencing guidelines, which shall take effect

only if enacted into law" [emphasis added]).

The suggestion in Justice Kafker's and Justice Wendlandt's

concurrences that it is uncritical deference to the Legislature

that drives my conclusion that we must uphold the imposition of

4 Within the guidelines themselves, the Massachusetts

District Attorneys Association responded in objection both to

the guidelines being issued to guide judges, without approval

and consent from the Legislature, and to the substance of the

guidelines based on the district attorneys' "collective

experience, the rights of victims of crime, the impact of the

opioid epidemic, and [the district attorneys'] vital role as

elected officials, protecting the public and representing the

public's interest" (footnote omitted). See Massachusetts

Sentencing Commission, Advisory Sentencing Guidelines 12-13

(Nov. 2017).

20

life without parole on individuals from eighteen to twenty-one

deeply misunderstands my position. It is our constitutional

doctrine looking to contemporary standards of decency that

commands that we consider our Legislature's judgments as to what

age constitutes adulthood. We must ground our art. 26

proportionality analysis to reflect society's values as

expressed through legislative judgments. The objective indicia

of contemporary standards of decency in our Commonwealth reflect

a societal view that individuals from eighteen to twenty-one are

adults, and nothing from these objective sources demonstrates

that society's evolving standards of decency consider the

mandatory imposition of life without parole to be cruel or

unusual when imposed on individuals within this age range who

have been convicted of murder in the first degree.

These standards of decency are not unique to the

Commonwealth. In ascertaining evolving standards of decency,

"judicial opinions and legislative actions at the State,

Federal, and international levels help to inform our

understanding of what art. 26 protects." Okoro, 471 Mass. at

61. As discussed in detail infra, thirty-six jurisdictions

permit the imposition of this punishment for this category of

homicide offenders, and only two States before today have

concluded, under their own Constitutions, that the mandatory

21

imposition of life without parole on adults from eighteen to

twenty-one is cruel or unusual.5

3. Precedent. Precedent relied on by the court is

specific to the sentencing of juveniles under the age of

eighteen and does not apply to the sentencing of adults. When

considering the proportionality of a sentencing practice as it

relates to a particular class of offenders, precedent from both

the Supreme Court and this court distinguishes juveniles under

the age of eighteen from adults eighteen and older.

The Supreme Court first made this distinction explicit in

Roper, 543 U.S. 551. Looking to objective indicia of national

consensus and societal understandings, supported by scientific

and sociological studies, the Court concluded that the

imposition of the death penalty on juvenile homicide offenders

violates the Eighth Amendment's proscription against cruel and

unusual punishment. See id. at 567-570. Importantly, the Court

recognized in Roper that the qualities that distinguish

juveniles from adults "do not disappear when an individual turns

5 The court's reliance on the twenty-three jurisdictions

that do not mandate life without parole for any crime regardless

of the age of the offender as evidence that contemporary

standards of decency deem cruel or unusual the imposition of

life without parole for offenders from eighteen to twenty-one

for the crime of murder in the first degree confounds logic. To

follow the court's reasoning would be to suggest that the

sentence of life without parole is cruel or unusual in the eyes

of contemporary standards of decency for any offender convicted

of the offense.

22

[eighteen]." Id. at 574. Rather, because "[t]he age of

[eighteen] is the point where society draws the line for many

purposes between childhood and adulthood," the Court, deferring

to societal norms informed by legislative enactments, determined

eighteen to be the defining line at which a person may be

treated as an adult for the purpose of punishment. Id. at 569,

574, Appendices B-D. The cases following Roper have all

operated within this societal line.

In Graham, 560 U.S. 48, the Court next addressed juveniles

convicted of nonhomicide offenses sentenced to life imprisonment

without the possibility of parole. In answering the question of

proportionality, the Court again turned to objective indicia of

national consensus, expressed through legislative enactments and

State practice, and considered the culpability of juveniles as

compared to the severity of the punishment in order to inform

its own independent judgment whether the sentencing practice

violated the Eighth Amendment. Id. at 61-63, 67. This analysis

led the Court to conclude that, for juveniles who have not

committed homicide offenses, the imposition of life without

parole is cruel and unusual under the Eighth Amendment. Id. at

82.

Miller, 567 U.S. at 465, which followed Graham, formed the

basis for our jurisprudence in the Commonwealth concerning

proportionality as it relates to sentencing practices applied to

23

juveniles. In Miller, the Supreme Court held that "mandatory

life without parole for those under the age of [eighteen] at the

time of their crimes violates the Eighth Amendment's prohibition

on 'cruel and unusual punishments.'" Id. The Court in Miller

predicated its conclusion on two strands of precedent: the

first, including Roper and Graham and their consideration of the

culpability of juveniles in light of the severity of the

sentences imposed; and the second, involving the prohibition

against the mandatory imposition of capital punishment due to

the absence of consideration of the individual characteristics

of the offender and the details of the offense. See id. at 470.

From Roper and Graham's teachings, the Court declared in

Miller that "children are constitutionally different from adults

for purposes of sentencing." Miller, 567 U.S. at 471. This

declaration rests firmly on principles of common sense, science,

and social science regarding children, their unique

characteristics, and how they have been treated in the law. Id.

at 471-472, 481. Based on these principles regarding children,

considered in conjunction with cases where individualized

sentencing is required before the death penalty is imposed, the

Court concluded that the Eighth Amendment requires an

individualized assessment of youth and its attendant

24

characteristics before such a harsh penalty may be imposed on a

juvenile homicide offender.6 See id. at 475-477, 479-480.

In so ruling in Miller, the Court emphasized that its

holding was limited to children, and that its precedent on adult

sentencing was not applicable to the sentencing of juvenile

offenders. Id. at 481 ("Harmelin[, which addressed

constitutionality of life without parole sentence for adult

convicted of possessing 672 grams of cocaine,] had nothing to do

with children and did not purport to apply its holding to the

sentencing of juvenile offenders"). Indeed, as the Court noted,

"a sentencing rule permissible for adults may not be so for

children." Id. The Court cited several examples of punishments

that "generally comport[] with the Eighth Amendment" -- except

when it comes to children -- and emphasized that "'[o]ur history

is replete with laws and judicial recognition' that children

cannot be viewed simply as miniature adults.'" Id., quoting

J.D.B. v. North Carolina, 564 U.S. 261, 274 (2011). And thus,

6 Because the decision in Miller did not categorically bar a

penalty for a class of offenders but was based on principles

established in Roper and Graham, as well as the Supreme Court's

individualized sentencing cases, the Court relied less on

"objective indicia of society's standards" to gauge a national

consensus. See Miller, 567 U.S. at 483. The Court,

nevertheless, surveyed the various jurisdictions and counted

twenty-nine (twenty-eight States and the Federal government)

that mandatorily imposed life without parole on juvenile

homicide offenders. Id. at 482-483 & n.9.

25

the Court noted, "it is the odd legal rule that does not have

some form of exception for children."7 Miller, supra.

With this Supreme Court precedent concerning juvenile

sentencing as the foundation, we decided Diatchenko I, 466 Mass.

at 657-658. Our inquiry in Diatchenko I was limited and

precise, given Miller's prior determination that the mandatory

imposition of life without the possibility of parole for

juvenile offenders was disproportionate under the Eighth

Amendment. See Diatchenko I, supra at 667 ("Pursuant to Miller,

[567 U.S. at 479, 489], we conclude that this mandatory sentence

violates both the Eighth Amendment prohibition against 'cruel

and unusual punishment[]' and the analogous provision of the

Massachusetts Declaration of Rights set forth in art. 26"). The

remaining question for us in Diatchenko I was whether an

individualized assessment of a juvenile offender could ever

7 It is worth noting that when the Supreme Court has

assessed whether punishment is barred by the Eighth Amendment

when applied to a category of offenders who are not juveniles,

it has placed great emphasis on contemporary standards of

decency, gleaned from legislative judgments. See Atkins, 536

U.S. at 313-316, 321 (death penalty for intellectually disabled

unconstitutional, determined by "review[ing] the judgment of

legislatures that have addressed the suitability of imposing the

death penalty on the [intellectually disabled] and then

consider[ing] reasons for agreeing or disagreeing with their

judgment"); Ford v. Wainwright, 477 U.S. 399, 406-410 (1986)

(death penalty for insane prisoners unconstitutional where

execution of them was condemned at common law, and at time of

decision "no State in the Union permit[ted] the execution of the

insane").

26

constitutionally justify the imposition of life without parole

under art. 26. Id. at 668. We concluded that the answer to

that singular question was no. Id. at 670-671. In light of the

unique characteristics of juvenile offenders, we concluded that

an individualized assessment could never result in a

determination that a juvenile was "irretrievably depraved," at

the time of sentencing, such that "a sentence of life without

parole should be imposed on a juvenile homicide offender." Id.

at 670, quoting Roper, 543 U.S. at 570.

While we relied on "current scientific research on

adolescent brain development," combined with "the myriad

significant ways that this development impacts a juvenile's

personality and behavior," in Diatchenko I, 466 Mass. at 669, to

make this determination, our focus was on a legislatively

defined category of individuals constitutionally deserving of

special treatment. We did not look to science to carve out this

group; legislation had already defined it. See id. at 659 n.8.

We determined that, "under art. 26, the 'unique characteristics

of juvenile offenders' should weigh more heavily in the

proportionality calculus than the United States Supreme Court

required under the Eighth Amendment," Commonwealth v. Perez, 477

Mass. 677, 683 (2017), S.C., 480 Mass. 562 (2018), quoting

Diatchenko I, supra at 671, and we used scientific research to

augment this weighing.

27

Two features of our decision in Diatchenko I render it

unsuited and unable to answer the question before us today. The

first, and most pronounced, reason: it was limited to juveniles

under the age of eighteen. See Diatchenko I, 466 Mass. at 659

n.8. More specifically, the decision was limited to a class of

offenders predefined by the Legislature as juveniles. Indeed,

the decision in Diatchenko I made painstakingly clear that its

holding was restricted to juvenile offenders under the age of

eighteen.8 Justice Kafker's concurrence poses the question

See Diatchenko I, 466 Mass. at 658-659 ("We further

8

conclude that the mandatory imposition of a sentence of life in

prison without the possibility of parole on individuals who were

under the age of eighteen when they committed the crime of

murder in the first degree violates the prohibition against

'cruel or unusual punishments' in art. 26 of the Massachusetts

Declaration of Rights, and that the discretionary imposition of

such a sentence on juvenile homicide offenders also violates

art. 26 because it is an unconstitutionally disproportionate

punishment when viewed in the context of the unique

characteristics of juvenile offenders" [emphases added]); id. at

669 ("In the present circumstances, the imposition of a sentence

of life in prison without the possibility of parole for the

commission of murder in the first degree by a juvenile under the

age of eighteen is disproportionate not with respect to the

offense itself, but with regard to the particular offender"

[emphasis added]); id. at 671 ("With current scientific evidence

in mind, we conclude that the discretionary imposition of a

sentence of life in prison without the possibility of parole on

juveniles who are under the age of eighteen when they commit

murder in the first degree violates the prohibition against

'cruel or unusual punishment[]' in art. 26" [emphasis added]);

id. ("Given the unique characteristics of juvenile offenders,

they should be afforded, in appropriate circumstances, the

opportunity to be considered for parole suitability" [emphasis

added]); id. at 673 ("In light of our conclusion that the

imposition of a sentence of life in prison without the

possibility of parole on juvenile offenders who are under the

28

"whether there is a meaningful constitutional difference between

overruling the Legislature's decision that it is permissible to

sentence juveniles to life in prison without the possibility of

parole and overruling the Legislature's decision that it is

permissible to sentence eighteen through twenty year olds to

life in prison without the possibility of parole." See ante

at . But Diatchenko I answers that question; there is. The

decision in Diatchenko I rested on the recognition that

juveniles are "constitutionally different from adults for

purposes of sentencing." Id. at 670, 674, quoting Miller, 567

U.S. 460, 471. See Diatchenko I, supra at 675 (Lenk, J.,

concurring) ("Pivotal to this holding . . . is the recognition

that 'children are constitutionally different from adults for

purposes of sentencing'" [citation omitted]). In Diatchenko I,

we did not venture to determine who qualified as a juvenile or

look to science to draw the line between childhood and

adulthood; instead, we relied on the prefixed line established

by society and the Legislature to issue our holding. See id. at

659 n.8. Where that prefixed line places eighteen, nineteen,

and twenty year olds on the side of adulthood, and thus not

age of eighteen when they commit the crime of murder in the

first degree is unconstitutional, the language in the fourth

sentence of G. L. c. 265, § 2, which sets forth the exception to

parole eligibility, is invalid as applied to juvenile homicide

offenders" [emphases added]).

29

entitled to distinct constitutional treatment, Diatchenko I does

not dictate the result here. As the Supreme Court in Miller

underscored, precedent relating to adult sentencing is not

applicable to juveniles, and inversely, precedent relating to

juvenile sentencing is not applicable to adults. See Miller,

567 U.S. at 481.

The second reason Diatchenko I cannot resolve the

categorical question in this case relates to the court's inquiry

there and the reliance on science to assess proportionality. As

discussed infra, science is important when considering

proportionality as it relates to the offender. Diatchenko I,

466 Mass. at 669-670, establishes that. But, as the court, the

concurrences, and the p

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