State v. Ortiz

658 August 8, 2024 No. 28

IN THE SUPREME COURT OF THE

STATE OF OREGON

STATE OF OREGON,

Petitioner on Review,

v.

STEPHANIE ANDREA ORTIZ,

Respondent on Review.

(CC 20CR23850) (CA A175738) (SC S070216)

En Banc

On review from the Court of Appeals.*

Argued and submitted January 11, 2024.

Joanna L. Jenkins, Assistant Attorney General, Salem,

argued the cause and filed the briefs for petitioner on

review. Also on the briefs were Ellen F. Rosenblum, Attorney

General, and Benjamin Gutman, Solicitor General.

Peter G. Klym, Deputy Public Defender, Office of Public

Defense Services, Salem, argued the cause and filed the

brief for respondent on review. Also on the brief was Ernest

G. Lannet, Chief Defender, Criminal Appellate Section.

BUSHONG, J.

The decision of the Court of Appeals is reversed, and

the case is remanded to the Court of Appeals for further

proceedings.

Duncan, J., concurred and filed an opinion.

James, J., concurred and filed an opinion, in which Masih, J.,

joined, and in which Duncan, J., joined through “Part I.”

______________

* Appeal from Josephine County Circuit Court, Brandon S. Thueson, Judge.

325 Or App 134, 528 P3d 795 (2023).

Cite as 372 Or 658 (2024) 659

660 State v. Ortiz

BUSHONG, J.

At defendant’s criminal trial on a charge of driv-

ing under the influence of intoxicants (DUII), the arrest-

ing officer described the two field sobriety tests (FSTs) that

she had administered to defendant—the walk-and-turn

and the one-leg-stand tests1—as “standardized” tests that

are “designed to determine impairment” and supported by

“studies conducted to prove their validity.” Defendant did

not object to that testimony, and a jury found her guilty of

DUII. The Court of Appeals concluded that allowing that

testimony constituted plain error because it was scientific

evidence received without an adequate foundation, and the

court exercised its discretion to reverse the conviction based

on that error, concluding that it “was not harmless.” State v.

Ortiz, 325 Or App 134, 139, 142, 528 P3d 795 (2023).2

We allowed review to address the application of

plain-error review in this context. As we will explain, most

of the officer’s testimony about the two FSTs was admissi-

ble. But even if receiving part of the officer’s testimony con-

stituted plain error—an issue that we need not decide—we

conclude that the Court of Appeals abused its discretion in

reversing based solely on its determination that the error

was not harmless. That conclusion is not a legally sufficient

basis for reversal on plain-error review under our prior cases

and the Court of Appeals’ own precedent. Accordingly, we

reverse and remand to the Court of Appeals to consider the

appropriate factors in exercising its discretion and, if neces-

sary, address defendant’s remaining assignment of error.

I. BACKGROUND

A. Facts and Trial Proceedings

We summarize the pertinent facts presented at

trial to place our analysis of the disputed evidentiary issue

in context.

1

The walk-and-turn test involves taking nine heel-to-toe steps along a

straight line, turning as instructed, and taking nine steps back along the same

line in the same manner. The one-leg-stand test involves balancing on one leg for

30 seconds. See OAR 257-025-0020(1)(b), (c) (describing tests).

2

The Court of Appeals did not consider defendant’s other assignment of

error, which concerned the admissibility of other testimony.

Cite as 372 Or 658 (2024) 661

Based on a 9-1-1 call from a concerned citizen,

Officer Miguel arrived at the scene where a white SUV

was parked. Miguel approached defendant, who matched

the caller’s description of the SUV’s driver. Miguel could

smell alcohol on defendant’s breath, observed that her eyes

were “watery,” and noticed that she exhibited mood swings

ranging from anger, to crying, to laughing. Defendant told

Miguel that she had consumed five beers that evening, that

she felt a “little bit tipsy,” and that she did not believe that

she was safe to drive. However, defendant denied that she

had been driving the vehicle.

Miguel then contacted the 9-1-1 caller to confirm

that defendant had been driving and proceeded to inves-

tigate defendant for DUII. As part of that investigation,

Miguel asked defendant to perform two FSTs: the walk-

and-turn test and the one-leg-stand test. After observing

defendant’s performance on those tests, Miguel arrested

defendant for DUII. At the police station, defendant agreed

to take a breath test. That test, administered about one

hour and 10 minutes after the 9-1-1 call that had started

the investigation, indicated that defendant’s blood alcohol

content (BAC) was .07 percent.3

At trial, Miguel testified in some detail about the

FSTs that she had administered. She first described her

training at the police academy, which included a “full course”

on “standardized field sobriety tests” that included a “wet

lab,” where trainees obtain hands-on experience adminis-

tering the FSTs to individuals who have been drinking. She

then described the tests:

“[PROSECUTOR]: What are the purposes of the field

sobriety tests?

“MIGUEL: They are divided attention tests. They are

designed to determine impairment.

“[PROSECUTOR]: Okay. And what field sobriety tests

did you perform on the [d]efendant?

3

A person commits the offense of DUII if the person has a BAC of .08 percent

or more or is under the influence of intoxicating liquor when driving a vehicle.

ORS 813.010(1). In this case, the state opted to proceed only on an “under the

influence” theory of DUII.

662 State v. Ortiz

“MIGUEL: We performed the walk-and-turn test and

the one-leg stand.

“[PROSECUTOR]: Are those tests used by law enforce-

ment around the country?

“MIGUEL: Yes. Those are standardized tests.

“[PROSECUTOR]: Why are those tests used around

the country?

“MIGUEL: Like I said, they are standardized. There

have been studies conducted to prove their validity. * * *

[I]t’s a national standard, so it’s not just something that

I made up or anybody in my department made up. It is a

national standardized test. It is conducted the same way, it

has the same set of instructions, same set of rules for each

person that performs that nationwide.”

That testimony was received without objection.4 Miguel

then described how she administers the tests, the instruc-

tions she had given to defendant, and how defendant had

performed. Miguel’s bodycam footage, which showed her

interview of defendant at the scene and defendant’s perfor-

mance on the FSTs, was also admitted into evidence and

played for the jury.

Defendant testified at trial that her husband had

been driving the white SUV immediately before Miguel

arrived on the scene. Defendant admitted that she had been

drinking earlier that evening and that she had told Miguel

at the time that she had not felt safe to drive. In closing

argument, defense counsel argued that the jury could find

defendant not guilty of DUII either because the state had not

proved beyond a reasonable doubt that defendant had been

driving the vehicle, or because, even if the jury concluded

that defendant had been driving, the state had not proved

that defendant had been under the influence of intoxicating

liquor. Among other things, defense counsel pointed out that

defendant’s BAC of .07 percent when she took the breath

4

Miguel’s testimony about the FSTs was elicited by questions from the pros-

ecutor that did not require Miguel to describe the tests in scientific terms. The

questions that elicited the objectionable testimony were as follows: (1) “Are those

tests used by law enforcement around the country?”; and (2) “Why are those tests

used around the country?” Phrased that way, the questions themselves were not

objectionable, but defendant could have objected and moved to strike Miguel’s

answers for lack of foundation.

Cite as 372 Or 658 (2024) 663

test was below the .08 percent standard, and he suggested

that defendant’s poor performance on the FSTs could have

been caused by her emotional state or embarrassment, not

intoxication.

The jury returned a guilty verdict. Defendant

appealed.

B. Appellate Proceedings

Defendant raised two assignments of error on

appeal. The Court of Appeals did not consider the first

assignment of error because it reversed on the second. Ortiz,

325 Or App at 137.5 In that assignment of error, defendant

challenged the trial court’s admission of Miguel’s testimony

that the two FSTs she administered were “national[ly] stan-

dardized” tests that were “designed to determine impair-

ment” and supported by “studies conducted to prove their

validity.” Defendant acknowledged that she had not pre-

served the error by timely objecting to that testimony, but

she contended that the trial court had “plainly erred” by

receiving that “scientific evidence” without requiring the

state to lay a foundation for its admission.

The Court of Appeals agreed with defendant, con-

cluding that the disputed testimony was scientific evidence

under OEC 702,6 and that the state was required to lay

an adequate foundation addressing the factors in State v.

Brown, 297 Or 404, 417, 687 P2d 751 (1984), and State v.

O’Key, 321 Or 285, 299-306, 899 P2d 663 (1995), before the

evidence could be admitted.7 Ortiz, 325 Or App at 137-38.

5

Defendant asserted in her first assignment of error that the trial court had

erred by allowing Officer Miguel to testify that defendant’s performance on the

FSTs was “consistent” with her observations and to compare defendant’s perfor-

mance on the FSTs to what she “would expect a sober person to do.” Defendant

objected at the end of that testimony based on “foundation and speculation,” and

the trial court overruled the objection. As noted, the Court of Appeals did not reach

that assignment of error, and the parties did not raise that issue in this court.

6

OEC 702 provides, “If scientific, technical or other specialized knowledge

will assist the trier of fact to understand the evidence or to determine a fact in

issue, a witness qualified as an expert by knowledge, skill, experience, training

or education may testify thereto in the form of an opinion or otherwise.”

7

The Brown/O’Key factors for admissibility of scientific evidence include

the following: (1) whether the evidence is generally accepted in the field; (2) the

expert’s qualifications; (3) prior use of the evidence; (4) the potential rate of error;

(5) the existence of specialized literature; (6) the novelty of the evidence; and

664 State v. Ortiz

The court further concluded that, “[b]ecause the state did

not attempt to lay an adequate Brown/O’Key foundation, it

would be error for a trial court to admit” the testimony over

an appropriate objection. Id. at 138. But, because defendant

had not objected to that testimony at trial, the court turned

to “whether it was plain error for the trial court to not recog-

nize the testimony as obviously scientific testimony lacking

a foundation and, accordingly, sua sponte exclude its admis-

sion into evidence.” Id. at 139.

The court explained that, under Ailes v. Portland

Meadows, Inc., 312 Or 376, 381-82, 823 P2d 956 (1991),

plain-error review “involves a two-step inquiry[.]” Ortiz, 325

Or App at 137. The court must “first determine whether the

error is plain, and second, [decide] whether to exercise [its]

discretion to consider the error.” Id. Under the first step, the

court must determine whether the error is (1) one of law,

(2) obvious and not reasonably in dispute, and (3) “ ‘apparent

on the record without requiring the court to choose among

competing inferences.’ ” Id. (quoting State v. Vanornum, 354

Or 614, 629, 317 P3d 889 (2013)). The Court of Appeals con-

cluded that the error in admitting Miguel’s testimony about

the FSTs was plain and that the trial court “had a duty

to exclude the evidence.” Id. at 139 (citing State v. Beltran-

Chavez, 286 Or App 590, 614, 400 P3d 927 (2017); State v.

Eatinger, 298 Or App 630, 448 P3d 636 (2019); and State v.

Reid, 312 Or App 540, 492 P3d 728 (2021)).

Then, at the second step of the plain-error analysis,

the court exercised its discretion to consider the error and

reversed the conviction, “as [it had done] in Reid.” Ortiz,

325 Or App at 140. The court explained that, “due to the

inherently persuasive effect of scientific evidence and the

prosecution’s focus on the FST results in its closing argu-

ment,” it could not “say that the testimony * * * had little

likelihood of affecting the verdict.” Id. at 142. The court also

observed that “it is difficult to see how the state could have

laid an adequate Brown/O’Key foundation for Miguel to tes-

tify as a scientific expert had defense counsel objected to the

(7) the extent to which the evidence relies on the subjective interpretation of the

expert. O’Key, 321 Or at 299 (citing Brown, 297 Or at 417). That nonexclusive list

is not intended “to be taken as a mechanical checklist of foundational require-

ments.” Id. at 300.

Cite as 372 Or 658 (2024) 665

evidence.” Id. Thus, the court concluded that the error “was

not harmless.” Id.

Judge Pagán dissented. He “disagree[d] that any

error [had] occurred below,” and further opined that, “if

there was error, it was harmless.” Id. at 143 (Pagán, J., dis-

senting). In addition, Judge Pagán thought that “expanding

the doctrine of requiring sua sponte striking of testimony

beyond unequivocal vouching” was unwarranted, and that

the applicable factors weighed against exercising discretion

to address the error in this case. Id.

We allowed review to address the appropriate appli-

cation of plain-error review in this context.

II. DISCUSSION

A. Standard of Review

We employ “two different standards of review” in

determining whether the Court of Appeals properly reversed

on plain-error review. State v. Gornick, 340 Or 160, 167,

130 P3d 780 (2006). First, we consider “whether the Court

of Appeals committed an error of law in determining that

the three elements under the first step of the plain error

analysis [have] been satisfied.” Id. (citing Ailes, 312 Or at

382). Second, we consider whether the Court of Appeals

abused its discretion in reversing based on that error. Id. If

the Court of Appeals exercises its discretion to reverse on

plain-error review, it “must articulate its reasons for doing

so.” Ailes, 312 Or at 382.

In Ailes, we identified the following nonexclusive list

of factors that an appellate court may consider in deciding

whether to exercise its discretion to reverse on plain-error

review: “the competing interests of the parties; the nature

of the case; the gravity of the error; the ends of justice in the

particular case; how the error came to the court’s attention;

and whether the policies behind the general rule requir-

ing preservation of error have been served[.]” 312 Or at 382

n 6. Those factors “do not comprise a necessary or complete

checklist; they merely are some of the permissible consider-

ations.” Id.

666 State v. Ortiz

We have held that the Court of Appeals abused its

discretion in reversing on plain-error review without eval-

uating the appropriate factors. State v. Fults, 343 Or 515,

522-23, 173 P3d 822 (2007). And we have frequently warned

that the decision to reverse based on a plain error “ ‘should

be made with utmost caution’ ” because it “ ‘is contrary to the

strong policies requiring preservation and raising of error.’ ”

Gornick, 340 Or at 166 (quoting Ailes, 312 Or at 382); see

also Vanornum, 354 Or at 630-31 (same). Thus, it is “ ‘only in

rare and exceptional cases’ ” that an appellate court should

reverse based on an error that had not been raised in the

trial court. Gornick, 340 Or at 166 (quoting Hotelling v.

Walther, 174 Or 381, 385-86, 148 P2d 933 (1944)).

B. The First Step of Plain-Error Review

Under the first step of the Ailes framework, the

Court of Appeals was required to determine whether the

admission of Miguel’s testimony regarding the FSTs without

an adequate foundation constituted a plain error. To make

that determination, the court must examine the following

three factors: “(1) whether the claimed error [was] one of law;

(2) whether the claimed error [was] obvious and not reason-

ably in dispute; and (3) whether the claimed error appears

on the record.” State v. Chitwood, 370 Or 305, 311, 518 P3d

903 (2022); see also Vanornum, 354 Or at 629 (listing factors

and explaining that an error is not apparent on the record if

it requires the reviewing court to “choose among competing

inferences”).

Determining whether the admission of Miguel’s

testimony about the FSTs constituted a plain error begins

with the foundational requirements for FST evidence that

we adopted in O’Key. There, we held that evidence about the

defendant’s performance on a different FST—the horizontal

gaze nystagmus (HGN) test8 —is scientific evidence that is

admissible in a DUII case to establish that a defendant was

8

As explained in O’Key, the HGN test “is designed to detect whether a per-

son’s eyes demonstrate nystagmus under certain conditions.” 321 Or at 294.

Nystagmus is a physiological phenomenon involving an involuntary rapid move-

ment, often described as jerking or bouncing, of the eyeball. HGN arises from

an eye’s inability to maintain visual fixation—resulting in observable jerking

or bouncing of the eyeball—as the eye tracks a steadily moving object such as a

finger or pencil across a horizontal plane of vision. Id.

Cite as 372 Or 658 (2024) 667

under the influence of intoxicating liquor, “subject to a foun-

dational showing that the officer who administered the test

was properly qualified, the test was administered properly,

and the test results were recorded accurately[.]” 321 Or at

322.9 In reaching that conclusion, we discussed the develop-

ment of the HGN, walk-and-turn, and one-leg-stand tests in

some detail.

As we explained, those FSTs were developed by

the Southern California Research Institute (SCRI) for the

National Highway Traffic Safety Administration (NHTSA)

in the 1970s. O’Key, 321 Or at 309. In 1981, another SCRI

study for NHTSA standardized the procedures for admin-

istering and scoring those FSTs. Id. at 310.10 The Oregon

State Police (OSP), acting in consultation with the Board on

Public Safety Standards and Training pursuant to author-

ity delegated by the legislature, has approved the three fore-

going field sobriety tests and others, and has adopted rules

describing how the FSTs should be administered. Id. at 289-

90 (describing rule making process); OAR 257-025-0012(1)

(listing approved FSTs); OAR 257-025-0020(1) (describing

procedures for administering FSTs).

Although the approved FSTs have common origins,

we also explained in O’Key that there is a significant dif-

ference between the HGN test and the two FSTs that are

at issue in this case. Specifically, we noted that, although

the function of the HGN test, “like [the] other field sobri-

ety tests, is to spot ‘observable symptoms’ or ‘signs’ of alco-

hol impairment,” the HGN test “rests on a manifestation of

alcohol consumption [that is] not easily recognized or under-

stood by most people.” Id. at 297. In contrast, the walk-and-

turn and the one-leg-stand tests “obtain their legitimacy

from effects of intoxication based on propositions of common

knowledge.” Id. We noted that such propositions included

“commonly known observable symptoms or signs of alcohol

9

We further concluded in O’Key that HGN evidence is not admissible to

prove that a defendant had a BAC of .08 percent or more. 321 Or at 322-23.

10

One study concluded that the HGN test was the most accurate of the FSTs,

with an accuracy rate of 77 percent, compared to 68 percent for the walk-and-

turn test and 65 percent for the one-leg-stand test. O’Key, 321 Or at 310 (citing

Comment, Can Your Eyes Be Used Against You? The Use of the Horizontal Gaze

Nystagmus Test in the Courtroom, 84 J Crim L & Criminology 203, 209-10 (1993)).

668 State v. Ortiz

intoxication” that are sufficiently accepted that a court may

take judicial notice of them. Id. (citing State v. Clark, 286

Or 33, 39-40, 593 P2d 123 (1979) (internal quotation marks

omitted)).11

We further discussed the walk-and-turn and one-

leg-stand tests in State v. Mazzola, 356 Or 804, 820, 345 P3d

424 (2015), where we held that exigent circumstances made

the warrantless administration of roadside FSTs in a DUII

investigation constitutionally permissible. In reaching that

conclusion, we described the rationale behind the admission

of the FST results in a DUII case:

“Psychomotor [field sobriety tests] test balance and divided

attention, or the ability to perform multiple tasks simulta-

neously. While balancing is not necessarily a factor in driv-

ing, the lack of balance is an indicator that there may be

other problems. Poor divided attention skills relate directly

to a driver’s exercise of judgment and ability to respond to

the numerous stimuli presented during driving. The tests

involving coordination (including the walk-and-turn and

the one-leg-stand) are probative of the ability to drive, as

they examine control over the subject’s own movements.”

Id. at 818 (quoting United States v. Horn, 185 F Supp 2d

530, 558 (D Md 2002) (brackets in Mazzola)). We also noted

that the legislature had defined “field sobriety test” in ORS

801.272 as “a means of detecting impairment.” Id.

It follows from our discussion of the walk-and-

turn and the one-leg-stand tests in O’Key and Mazzola

that, because the legislature has approved those tests as a

means of detecting impairment and they are designed to

spot observable symptoms or signs of alcohol intoxication

that are easily recognized and understood by most people,

law enforcement officers who are trained to administer

those FSTs can generally testify about their training, how

they conducted the tests, what they observed about a sus-

pect’s performance, and the conclusions they reached from

those observations. That testimony is subject only to the

11

In Clark, this court took judicial notice of 11 common physical manifes-

tations of intoxication: (1) odor of the breath; (2) flushed appearance; (3) lack of

muscular coordination; (4) speech difficulties; (5) disorderly or unusual conduct;

(6) mental disturbance; (7) visual disorders; (8) sleepiness; (9) muscular tremors;

(10) dizziness; and (11) nausea. 286 Or at 39-40.

Cite as 372 Or 658 (2024) 669

foundational showing “that the officer who administered the

test was properly qualified, the test was administered prop-

erly, and the test results were recorded accurately.” O’Key,

321 Or at 322.

The Court of Appeals concluded, however, that

Miguel went further when she testified that the walk-and-

turn and one-leg-stand tests are “nationally standardized”

tests that are “designed to determine impairment,” and

that they are supported by “studies conducted to prove their

validity.” That testimony, the court concluded, was “scien-

tific” evidence that required an additional foundational

showing to establish its scientific validity. Under our prior

cases, determining whether evidence is “scientific” evidence,

thereby requiring an additional foundational showing, gen-

erally “depends primarily on whether the trier of fact will

perceive the evidence” as scientific. State v. Marrington, 335

Or 555, 561, 73 P3d 911 (2003). We acknowledge that, by

invoking “the vocabulary of scientific research,” id. at 563,

Miguel’s testimony may have “implied that it was grounded

in science” and it is possible that the jury “would have viewed

the evidence that way,” State v. Henley, 363 Or 284, 301, 422

P3d 217 (2018).

However, Miguel’s testimony in its entirety was less

likely to be perceived as “scientific” than the expert testi-

mony that we addressed in Marrington and Henley.12 The

fact that law enforcement officers are trained to administer

the walk-and-turn and one-leg-stand tests in a standard-

ized way—one that has been approved by NHTSA and is

described in OSP rules—is a fact that, standing alone, does

not impermissibly suggest that the tests are grounded in

science. Similarly, the fact that those tests were authorized

by the legislature to “detect probable impairment,” ORS

801.272, does not necessarily suggest that they are grounded

in science. On the other hand, it is possible that a jury could

have understood from the terminology that Miguel used in

describing the FSTs that they were sufficiently grounded in

12

Marrington involved expert testimony explaining why children often delay

reporting sexual abuse. Henley involved expert testimony about how pedophiles

often “groom” children for sexual activity. In both cases, we held that the testi-

mony was “scientific” evidence that required a foundational showing of scientific

validity before the testimony could be admitted into evidence.

670 State v. Ortiz

science to require an additional foundational showing, as

the Court of Appeals concluded.

In any event, we need not decide whether the trial

court plainly erred in receiving that testimony without an

additional foundation if, assuming that the error was plain,

the case can be resolved at the second step of the Ailes

framework. We have employed that approach in other cases.

For example, in Fults, the Court of Appeals had

reversed a sentencing error on plain-error review. We, in

turn, reversed the Court of Appeals by assuming that the

error was plain and concluding that the Court of Appeals

had abused its discretion by reversing “based on the single

rationale that it [had] expressed[.]” 343 Or at 523. Similarly,

in State v. Ramirez, 343 Or 505, 173 P3d 817 (2007), the

trial court had imposed an enhanced sentence without sub-

mitting the enhancement factors to the jury. The Court

of Appeals reversed on plain-error review and remanded

for factfinding on the enhancement factors. We reversed

the Court of Appeals, stating that “it is more expeditious

to assume” plain error and “to move directly to the second

half of the Ailes analysis, viz., a determination whether the

Court of Appeals properly exercised its discretion to review

the alleged error.” Id. at 512. Considering the applicable

Ailes factors, we concluded that the Court of Appeals had

abused its discretion because, among other things, “it would

not advance the ends of justice” to remand for additional

factfinding since the evidence supporting an enhanced sen-

tence was “overwhelming.” Id. at 514.

We will employ that approach here.13 Assuming that

the error was plain, we will address whether the Court of

Appeals abused its discretion in reversing based on its artic-

ulated reason. As we will explain, reversing based solely on

a conclusion that a plain error was not harmless is inconsis-

tent with the analytical framework that we adopted in Ailes

and have consistently applied in our post-Ailes cases, and

13

The concurring opinion takes issue with that approach, concluding that

the error here was plain. That might be correct, but, because Miguel’s testimony

was less likely to be perceived as scientific than the expert testimony at issue in

our prior cases, we do not consider the answer at step one of the Ailes analysis to

be as clear as the concurring opinion suggests.

Cite as 372 Or 658 (2024) 671

is contrary to the approach the Court of Appeals itself had

previously adopted.

C. Exercising Discretion to Reverse on Plain-Error Review

As noted above, when the Court of Appeals exercises

its discretion to reverse on plain-error review, it “must artic-

ulate its reasons for doing so.” Ailes, 312 Or at 382. Here, the

Court of Appeals explained that it exercised its discretion to

reverse because it “[could] not say” that Miguel’s testimony

about the FSTs had little likelihood of affecting the verdict,

so the error “was not harmless.”14 Ortiz, 325 Or App at 142.

But that is not a legally sufficient reason to reverse on plain-

error review.

By reversing at step two of the Ailes plain-error

framework based on its conclusion that the error was not

harmless, the Court of Appeals failed to recognize the dif-

ference between an error that requires reversal and one that

might permit reversal. Under Article VII (Amended), sec-

tion 3, of the Oregon Constitution, an appellate court may

not reverse a criminal defendant’s conviction based on an

error—whether preserved or unpreserved—that is harm-

less. An error is considered harmless for purposes of that

constitutional standard if “there was little likelihood that

the error affected the jury’s verdict.” State v. Davis, 336 Or

19, 32, 77 P3d 1111 (2003). When an appellate court deter-

mines that there was little likelihood that an unpreserved

error affected the verdict, the court must affirm, regardless

of whether that error satisfies the criteria for plain error.15

Determining that an error is not harmless is necessary for

reversal, regardless of whether the error was preserved or

unpreserved.

14

The Court of Appeals was skeptical that the state “could have laid an ade-

quate Brown/O’Key foundation for Miguel to testify as a scientific expert had

defense counsel objected to the evidence.” Ortiz, 325 Or App at 142.

15

We have explained that a preserved evidentiary error “does not require

reversal if it is harmless—that is, if it had little likelihood of affecting the ver-

dict.” Henley, 363 Or at 307. The Court of Appeals has regularly applied that

principle in affirming based on the harmlessness of a plain error. See, e.g., State

v. Belen, 277 Or App 47, 55, 369 P3d 438 (2016) (stating that, in determining

whether to exercise discretion to correct a plain error, “[w]e begin with harmless-

ness, because, in this case, that issue is dispositive”); State v. Ross, 271 Or App

1, 12, 349 P3d 620, rev den, 357 Or 743 (2015) (affirming because “[t]he asserted

plain error was harmless”).

672 State v. Ortiz

But that determination alone does not provide suffi-

cient grounds for reversal on plain-error review because the

court may not exercise its discretion to reverse based solely

on its conclusion that a plain error was not harmless. That

standard applies to reversal based on a preserved error. To

reverse based on an unpreserved, plain error, the court must,

in addition to determining that the error was not harmless,

consider the factors that are relevant to the court’s exercise

of discretion at step two of the Ailes framework. Applying

the same standard for reversal—that the error simply not be

harmless—regardless of whether the error was preserved or

unpreserved would essentially eliminate the second step of

the Ailes analytical framework.

One of the factors listed in Ailes—the gravity of

the error—may include an assessment that to some degree

reflects the constitutional harmlessness standard, because,

as discussed above, the court would be required to affirm

if it determined that a plain error was unlikely to have

affected the verdict. But the cases that formed the basis of

the Ailes framework illustrate that the analysis is different

when the court determines that the gravity of an unpre-

served error warrants reversal. As we will explain, under

those cases, the gravity of an unpreserved error warrants

reversal where it is necessary to ensure that the ends of jus-

tice are satisfied under the circumstances. That determi-

nation is different than merely determining that reversal

would be constitutionally permissible.

We adopted the Ailes framework by “[e]xtrapolating”

from State v. Brown, 310 Or 347, 800 P2d 259 (1990). Ailes,

312 Or at 382. In Brown, a jury had convicted the defendant

of the aggravated murder of a witness and sentenced him to

death. We concluded on direct appeal that “the trial court

committed reversible error when it failed to instruct on the

causation element of aggravated murder of a witness.” 310

Or at 356. Reversal was appropriate even though the defen-

dant had not objected to the failure to instruct the jury on

that element because “the ends of justice [would] not other-

wise be satisfied.” Id. at 355. We explained that the ends

of justice warranted reversal in that case because the trial

court’s failure to instruct on causation “may have led the

Cite as 372 Or 658 (2024) 673

jury to convict [the] defendant without having found that

the victim’s status as a witness motivated the murder in any

way[,]” and we considered the error to be highly prejudicial

“because the missing element makes the difference between

life and death.” Id. at 356.

Our decision in Brown cited State v. Avent, 209 Or

181, 183, 302 P2d 549 (1956), for the proposition that an appel-

late court should determine whether the “ends of justice” war-

ranted reversal based on an unpreserved error. In Avent, the

defendant had raised unpreserved evidentiary and instruc-

tional errors on appeal from her second-degree murder convic-

tion. This court declined to review those errors, emphasizing

that the rule against considering unpreserved errors “will not

be relaxed unless the court, upon an examination of the entire

record, can say that the error is manifest and that the ends of

justice will not otherwise be satisfied.” 209 Or at 183.16

In constructing our current plain-error framework,

Ailes incorporated the standards that we had applied in

Brown and Avent by including “the gravity of the error” and

“the ends of justice” among the factors to be considered at

step two of the analysis in deciding whether to exercise dis-

cretion to reverse based on a plain error. Ailes, 312 Or at 382

n 6 (citing Brown, 310 Or at 355-56, and Avent, 209 Or at

183). In applying those factors, several of our cases address-

ing unpreserved errors—both before and after Ailes—illus-

trate the difference between determining when the gravity

of an unpreserved error justifies reversal to satisfy the ends

of justice and determining that such an error was not harm-

less under the constitutional standard.

In one case, decided only a year after Ailes—State

v. Jensen, 313 Or 587, 837 P2d 525 (1992)—the defendant

16

That standard was not met in Avent because the instructional error was

“obviously an inadvertence” and “would undoubtedly have been corrected” if it

had been called to the trial judge’s attention. 209 Or at 183. The unpreserved

evidentiary errors did not justify reversal, because, among other things, defen-

dant’s “felonious intent [was] conclusively shown by the fact that she pulled the

trigger five times” in killing the victim. Id. at 187. Thus, the court concluded that

the “ends of justice” did not require consideration of those claimed errors, stating

that, “[u]nless it is to be held that a person who shoots and kills another * * * is

to be excused because she testified that she intended no harm to her victim, * * *

there is no reason for this court to depart from customary procedure” to consider

the unpreserved errors. Id. at 188.

674 State v. Ortiz

challenged his conviction for first-degree assault and crimi-

nal mistreatment, assigning error to the trial court’s admis-

sion of a nurse’s testimony about statements made by the

three-year-old victim. On appeal, the defendant raised an

unpreserved Confrontation Clause challenge to that testi-

mony. The Court of Appeals considered that issue, reversing

and remanding for factual findings regarding the victim’s

availability. This court reversed, citing two cases—Ailes

and State v. Hickmann, 273 Or 358, 540 P2d 1406 (1975)—

and concluding, without further explanation, that the Court

of Appeals had “erred in reaching defendant’s confrontation

argument.” Jensen, 313 Or at 599.

In Hickmann, the trial court had granted a defen-

dant’s motion to suppress evidence obtained from a war-

rantless search, concluding that, although the police had

probable cause to search the defendant’s residence for

drugs, there were no exigent circumstances that justified

doing so without a warrant. The Court of Appeals agreed

but remanded to the trial court to make findings on an issue

that had not been previously raised—whether the defendant

had consented to the search. We reversed, concluding that

a remand to consider the issue of consent was not appro-

priate because “a question not raised and preserved in the

trial court will not be considered upon appeal unless upon

an examination of the entire record the court can find that

the error is manifest and that the ends of justice will not

otherwise be satisfied.” 273 Or at 360.17

Thus, in both the genesis of the Ailes framework

and in one of our first cases applying it, we concluded that

reversal on plain-error review could be appropriate where

the gravity of the error warrants reversal to satisfy the ends

of justice under the circumstances presented in a particular

case. That does not mean that the ends of justice is the only

factor at step two of the Ailes framework. But we have never

stated that the Court of Appeals, exercising its discretion

17

Hickmann cited two earlier cases for that proposition, State v. Abel, 241 Or

465, 406 P2d 902 (1965), and State v. Rupp, 251 Or 518, 446 P2d 516 (1968). In

Abel, this court declined to consider unpreserved evidentiary errors, stating that

an unpreserved error will not be considered on appeal unless the court finds that

the error “is manifest and that the ends of justice will not otherwise be satisfied.”

241 Or at 467. In Rupp, this court declined to review an instructional error for the

same reason. 251 Or at 519.

Cite as 372 Or 658 (2024) 675

on plain-error review, may reverse based solely on its deter-

mination that an error is not harmless under the constitu-

tional standard.18

Subsequent cases applying the Ailes analytical

framework confirm that discretion to reverse based on an

unpreserved error should be exercised with “utmost cau-

tion” and only when justified by the factors identified in

Ailes, rather than based on a determination that the error

was not harmless. For example, in Vanornum, we indicated

that determining whether an unpreserved error was plain

“is only half of [the] two-part inquiry.” 354 Or at 630. The

second step—determining whether to exercise discretion

to review the error—“entails making a prudential call that

takes into account an array of considerations, such as the

competing interests of the parties, the nature of the case,

the gravity of the error, and the ends of justice in the par-

ticular case.” Id. Ultimately, we explained, “a decision to

review a plain error is one to be made with the ‘utmost cau-

tion’ because such review undercuts the policies served by

the preservation doctrine.” Id. at 630-31 (citing Ailes, 312 Or

at 382).

Similarly, in Fults, the Court of Appeals had exer-

cised its discretion to reverse a plain sentencing error,

explaining only that “the state has no valid interest in

requiring [a] defendant to serve an unlawful sentence.” 343

Or at 523 (brackets omitted).19 Accepting that statement “in

the abstract,” we pointed out that “other factors also must

be considered and may outweigh that one.” Id. We indicated

that this court “has spelled out in the past precisely what

it expects, and what it will look to, respecting an appel-

late court’s choice to exercise its discretionary authority”

18

In State v. Lotches, 331 Or 455, 471-72, 17 P3d 1045 (2000), cert den, 534 US

833 (2001), we cited Brown in reversing convictions on two counts of aggravated

murder based on unpreserved instructional errors. We remanded those counts to

the trial court for further proceedings under Brown without discussing the factors

listed in Ailes, asking “whether there was a substantial likelihood of jury confu-

sion as to the underlying felony that was applicable to each count,” id. at 470, and

concluding that the instructional errors were plain and were “not harmless,” id. at

472. That use of the term “harmless” was based on our assessment that the error

was prejudicial in a way that required reversal, even in a plain error context.

19

The sentencing error in Fults was the imposition of a 36-month term of

probation on a charge carrying a presumptive sentence of 24 months’ probation.

676 State v. Ortiz

to consider an unpreserved error. Id. at 521. Specifically,

we had “spelled out” the factors in Ailes. Id. at 522 (quot-

ing Ailes factors and emphasizing that exercising discretion

to consider unpreserved error “should be made with utmost

caution”). We concluded that the Court of Appeals’ decision

to reverse an unpreserved error, “based on the single ratio-

nale that it [had] expressed, was an abuse of discretion.” Id.

at 523.

The “harmless error” approach to the exercise of

discretion employed by the Court of Appeals to reverse in

this case is inconsistent with those decisions and has been

expressly rejected by the Court of Appeals’ own precedent.

In State v. Inman, 275 Or App 920, 928, 366 P3d 721 (2015)

(en banc), rev den, 359 Or 525 (2016), the Court of Appeals

concluded that it “need not decide whether the trial court

plainly erred” in admitting without objection testimony chal-

lenged on appeal as vouching, because the court “would not

exercise [its] discretion to correct any plain error that might

exist on this record.” In reaching that conclusion, the court

applied the appropriate standards for plain-error review. Id.

(noting that, under Ailes, the decision to exercise discretion

to address an unpreserved claim of error “should be made

with utmost caution because such an action is contrary to

the strong policies requiring preservation and raising of

error” (internal quotation marks omitted; brackets omitted));

id. at 928-29 (noting that, in Fults, 343 Or at 521-22, and

in Vanornum, 354 Or at 630-31, this court had “expressed

its continued agreement with, and intent to adhere to” that

standard (internal quotation marks omitted)).

Applying Ailes, the Court of Appeals had first con-

sidered “the gravity of any error that could be said to have

plainly occurred,” Inman, at 929, concluding that, because

the vouching testimony at issue was not an “emphatic or

repeated comment on credibility,” any error was “not nearly

as grave as the errors that prompted reversals” in other

vouching cases, id. at 933. Next, the court considered “the

policies behind the general rule requiring preservation of

error,” id. at 934, explaining that the judicial system’s inter-

ests in requiring preservation and avoiding unnecessar-

ily repetitive legal proceedings are “weighty,” id. at 935. In

Cite as 372 Or 658 (2024) 677

assessing those interests, the court explained that “the ease

with which any error could have been avoided or corrected

should be a significant factor in an appellate court’s deci-

sion whether to exercise its discretion to correct a plain, but

unpreserved, error.” Id. The court then considered “the last

factor” that it saw as pertinent to the case: “the ends of jus-

tice.” Id. at 936. The court concluded that “the ends of justice

militate against such an exercise of discretion in this case”

when the gravity of any error—its significance in the con-

text of the case—was outweighed by the fact that a retrial

could easily have been avoided by a timely objection, given

the strong interests supporting preservation and avoiding

such a retrial. Id.

The court then addressed a dissenting opinion’s sug-

gestion that the court should reverse on plain-error review

because the admission of the vouching testimony “could not

be characterized as ‘harmless’ in the context of this case[.]”

Id. at 936. The court acknowledged that any error in admit-

ting the testimony “might not be deemed harmless if [the

court was] considering its effect in the context of a pre-

served evidentiary objection.” Id. But, the court explained,

“the harmless-error analysis does not govern our discretion-

ary decision about whether to address unpreserved claims

of error. Instead, we must balance the gravity of any error,

in the context of the ‘nature of the case,’ against the other

factors set forth in Ailes, Vanornum, Fults, and other plain-

error cases.” Id.

Shortly after the Court of Appeals’ decision in this

case, that court applied Inman in addressing an unpreserved

instructional error raised as plain error on appeal. State

v. Horton, 327 Or App 256, 535 P3d 338 (2023). There, the

court first concluded that the instructional error “was not

legally ‘harmless[.]’ ” Id. 264. That meant only that the court

“ha[s] discretion to correct the error, if [it] so choose[s][.]” Id.

But, the court explained, under its decision in Inman, “the

harmless-error analysis does not govern [the court’s] dis-

cretionary decision about whether to address unpreserved

claims of error.” Id. Instead, the court explained that it must

balance the gravity of any error, in the context of the nature

of the case, against the other Ailes factors. Id. (citing Inman,

678 State v. Ortiz

275 Or at 936). The Horton court was “ultimately unper-

suaded that the gravity of the error, the ends of justice, or

the other relevant considerations warrant[ed] exercising * * *

discretion to reverse and remand” for a new trial. Id. at 266.

Thus, in both Horton and Inman, the Court of

Appeals correctly considered the appropriate Ailes factors

in deciding whether to exercise its discretion to reverse

on plain-error review, concluding in both cases that the

harmless-error analysis did not govern its discretionary

decision. In this case, the court did not consider the Ailes

factors, choosing instead to reverse based solely on its con-

clusion that the error was not harmless. In doing so, the

court abused its discretion.

D. The Appropriate Disposition of This Case

In Fults, after concluding that the Court of Appeals

abused its discretion in reversing the defendant’s sen-

tence on plain-error review based on its stated reasons, we

remanded to the Court of Appeals because we could not say

that the court “could not, after weighing all the relevant fac-

tors, justify its choice in some different way.” 343 Or at 523.

Similarly, in Vanornum, after concluding that the Court

of Appeals erred in determining that it could not consider

an instructional error on plain-error review, we remanded

to the Court of Appeals to determine in the first instance

whether, in its discretion, it should consider defendant’s

claim of plain error. 354 Or at 631.

We employ the same approach here and remand

this case for further proceedings. On remand, the Court of

Appeals should consider the relevant Ailes factors, consis-

tent with the approach described in this opinion and applied

by the Court of Appeals in Inman and Horton, to decide

whether to exercise its discretion to reverse for a new trial

based on the unpreserved evidentiary error it identified. If

the court declines to exercise its discretion to reverse on that

error, it should, if necessary, address defendant’s remaining

assignment of error on appeal.

The decision of the Court of Appeals is reversed,

and the case is remanded to the Court of Appeals for further

proceedings.

Cite as 372 Or 658 (2024) 679

DUNCAN, J., concurring.

I join Justice James’s concurrence through “Part I.”

JAMES, J., concurring.

I concur with the majority that the Court of Appeals

erred in articulating reasons sufficient to support its exer-

cise of discretion to correct an error under our plain error

doctrine as articulated in Ailes v. Portland Meadows, Inc.,

312 Or 376, 381-82, 823 P2d 956 (1991). The doctrine of

preservation—of which plain error is a subcomponent—

and the doctrine of harmless error are distinct. They serve

different purposes and derive from different sources. The

Court of Appeals stated that one reason for its exercise of

discretion to waive preservation to correct the error here

under the plain error doctrine, was that the error was not

harmless. That flaw in articulated reasoning is sufficient to

vacate the decision and remand.

However, I part ways with the majority in its deci-

sion to assume, without deciding, that the claimed error in

this case qualified under the first prong of Ailes as plain and

obvious error apparent on the record. While certainly the

majority is within its discretion to assume, but not decide,

that issue, I would exercise my discretion differently. In my

view—for the benefit of the bench and bar, and to develop our

doctrine of plain error—we should answer that question.1

As I will explain, the testimony here, describing the

walk-and-turn and the one-leg-stand tests as “standardized

tests” that are “designed to determine impairment” and

supported by “studies conducted to prove their validity,”

purported to be scientific evidence. Under State v. Brown,

297 Or 404, 417, 687 P2d 751 (1984), and State v. O’Key, 321

1

I am reminded of Justice O’Connor’s observation, in her concurrence in City

of Ladue v. Gilleo, 512 US 43, 60, 114 S Ct 2038, 129 L Ed 2d 36 (1994), that

the practice of assuming without deciding carries certain consequences, includ-

ing lost opportunities to develop and refine the law in an area. See id. at 60

(O’Connor, J., concurring) (“I would have preferred to apply our normal analytical

structure in this case, which may well have required us to examine this law with

the scrutiny appropriate to content-based regulations. Perhaps this would have

forced us to confront some of the difficulties with the existing doctrine; perhaps

it would have shown weaknesses in the rule, and led us to modify it to take into

account the special factors this case presents. But such reexamination is part of

the process by which our rules evolve and improve.”)

680 State v. Ortiz

Or 285, 299-306, 899 P2d 663 (1995), Oregon courts have

an enhanced gatekeeping role with respect to scientific evi-

dence that is not present when faced with nonscientific evi-

dence. That enhanced gatekeeping role requires trial courts

to ensure, even in the absence of an objection by the parties,

that an adequate foundation exists in the record to establish

the reliability of scientific evidence before such evidence can

be admitted into an Oregon trial. When faced with unpre-

served evidentiary challenges on appeal, whether the evi-

dence was scientific should therefore properly be considered

by an appellate court as one, among many, factors in exer-

cising its discretion at the second step of Ailes.

I. THE TESTIMONY WAS SCIENTIFIC

In Brown, we said that scientific evidence was “evi-

dence that draws its convincing force from some principle of

science, mathematics and the like.” 297 Or at 407. In State

v. Henley, 363 Or 284, 301, 422 P3d 217 (2018), we elabo-

rated that “[e]xpert evidence is ‘scientific’ under OEC 702

when it is expressly presented to the jury as scientifically

grounded.”

The issue in this case is testimony by the officer

that the “standardized tests” he performed were “designed

to determine impairment” and supported by “studies con-

ducted to prove their validity.” The Court of Appeals con-

cluded that testimony was scientific by relying on Brown,

Henley, and three of its own cases—State v. Beltran-Chavez,

286 Or App 590, 614, 400 P3d 927 (2017), State v. Eatinger,

298 Or App 630, 632, 448 P3d 636 (2019), and State v. Reid,

312 Or App 540, 541, 492 P3d 728 (2021).

In Beltran-Chavez, the Court of Appeals considered

officer testimony that the defendant had “failed” the walk-

and-turn test. There, the Court of Appeals rejected an argu-

ment from the state that the term “failed” was not explicitly

scientific so as to trigger the concerns of Brown:

“Expert testimony that implicitly rests on scientific proposi-

tions can have just as much persuasive power as testimony

that makes its scientific backing explicit. * * * The proposi-

tions underlying an expert’s testimony are a critical focus

of the inquiry, not merely the words of the testimony. * * *

Cite as 372 Or 658 (2024) 681

As we understand it, that is a focus of the inquiry because

the jury will understand that the expert’s testimony rests

on underlying propositions about the topic of the testimony

and, because the expert is knowledgeable about the topic, is

likely to believe that those propositions are correct.”

Beltran-Chavez, 286 Or App at 613-14.

In Eatinger, the Court of Appeals applied Henley

and Beltran-Chavez in considering officer testimony that,

while performing Field Sobriety Tests (FST), the defendant’s

raising his arms was “an indicator.” 298 Or App at 634. The

officer testified that “[t]hese are all clues when they do the

scientific validation and the training.” Id. at 640. The Court

of Appeals held:

“[H]ad the state limited [the officer’s] testimony to his

observations of defendant’s performance on the FSTs, there

is little question that the admission of that testimony would

have been appropriate. The state—and, subsequently, the

trial court—did not, however, limit [the officer’s] testimony

in that way. And, applying to that testimony the distinction

that our case law has drawn between, on the one hand,

expert testimony based on training and experience, and,

on the other hand; testimony that is scientific, we are per-

suaded that [the officer’s] testimony was scientific. Indeed,

we do not view this to be a particularly close case. Although

an implication that an officer’s testimony is ‘guided by

principles grounded in science’ may, under certain circum-

stances, suffice to render that testimony scientific, * * *

here, [the officer] expressly testified as to the ‘scientific val-

idation’ of the ‘clues’ he had observed during defendant’s

performance of the FST’s; he also expressly adopted the

prosecutor’s statement that the FSTs were ‘the product of

scientific research.’ More than just implying that his testi-

mony was based on science rather than simply his training

and experience, [the officer] expressly—and repeatedly—

made that point.”

Id. at 644.

Finally, in Reid, the Court of Appeals considered a

plain error challenge to the admission of officer testimony

that a defendant had “failed” the FSTs. 312 Or App at 542.

Specifically, the testimony presented was as follows:

682 State v. Ortiz

“[PROSECUTOR:] And out of these eight steps, how

many—out of all the—any steps that can be detected, how

many would—what would be the amount that would be

detected that would be considered a fail?

“[OFFICER:] Four. Again, we take—we take a total-

ity of the circumstances in the test, so again, they may

not demonstrate—for example on this the horizontal gaze

nystagmus test, there’s six clues, I didn’t observe any here,

I didn’t expect to observe any on this particular test. So

that’s what we’re looking for, a failure on the specific test,

but that doesn’t—I take into account the other tests as

well.”

Id. (brackets in Reid).

Based on Henley, Beltran-Chavez, and Eatinger, the

state in Reid conceded that the testimony was plain and

obvious error apparent on the record, under Ailes, and that

the Court of Appeals would be properly within its discretion

to correct the error. Id. at 541.

In this case, the Court of Appeals’ majority applied

that line of precedent to conclude that the error here quali-

fied as plain error under Ailes. In my view, and in respectful

disagreement with the compelling dissent authored below

by Judge Pagán, the Court of Appeals’ majority was cor-

rect. The officer’s testimony here drew its force from five

critical terms—“standardized tests,” “designed,” “studies,”

“proof,” and “validity.” When presented together, as they

were, those terms unquestionably invoke the aura of scien-

tific grounding. A reasonable jury would likely understand

such testimony to imply a reliance on a “principle of science,

mathematics and the like.” Brown, 297 Or at 407. In light

of our decisions, as well as the Court of Appeals’ decisions

discussed, that error was plain, obvious, apparent on the

record, and not reasonably in dispute. Accordingly, the legal

error here opened the door to the Court of Appeals’ discre-

tion to correct under the second prong of Ailes.

II. AILES DISCRETION AND SCIENTIFIC EVIDENCE

Trials are intended to be fair and neutral grounds

upon which litigants can try their cases. As I have written

before:

Cite as 372 Or 658 (2024) 683

“[I]t is the litigants’ case to try, not the court’s. Every time

an appellate court reverses on plain error for something

not raised at trial, it sends a signal that the trial court, in

that instance, should have sua sponte injected itself into

that litigation. * * * Trial courts are rightly concerned, as

are we, about the effect on the perception of neutrality that

occurs when a court intervenes in the parties’ litigation in

that way.”

State v. Burris, 301 Or App 430, 434, 456 P3d 684 (2019).

Those considerations always lurk behind an appellate

court’s decision to exercise Ailes discretion.

However, although it is the role of the court to ensure

fairness, it is critical to recognize that fairness is not some-

thing owed only to the parties. Fairness is owed to the public

as well, so that faith in the integrity and legitimacy of court

proceedings, and court decisions, is maintained. In some

instances, ensuring the legitimacy of trial proceedings may

be in tension with allowing litigants to try their cases in the

manner they wish. Sometimes, preserving the integrity of

the proceeding requires a more active role by the trial court.

The admission of scientific evidence is such an instance.

From 1923 until 1984, Oregon courts followed the

admissibility standard for scientific evidence that was estab-

lished by Frye v. United States, 293 F 1013, 1013 (DC Cir

1923). Under Frye, scientific evidence could be introduced

in court proceedings if it was demonstratable and was gen-

erally accepted by the relevant scientific community. This

meant that the science must have passed through the exper-

imental phase and have “gained such standing and scien-

tific recognition among * * * [relevant] authorities as would

justify the courts in admitting expert testimony.” Frye, 293

F at 1014; see also Paul C. Giannelli, The Admissibility of

Novel Scientific Evidence: Frye v. United States, A Half-

Century Later, 80 Col Law Rev 1197, 1205 (1980) (explain-

ing that Frye “envisions an evolutionary process leading to

the admissibility of scientific evidence”). Under that test, the

relevant scientific community evaluated and determined the

validity of the proffered scientific evidence, rather than trial

court judges. Trial court judges simply had to determine

whether the science had gained sufficient acceptance in the

relevant community to warrant admission to trial. The Frye

684 State v. Ortiz

test “dominated the admissibility of scientific evidence for

more than half a century.” Id. at 1205.

In 1975, with the promulgation of the Federal Rules

of Evidence, the Frye standard began to decline in promi-

nence. The rules were written with a “liberal thrust” and

had a “general approach of relaxing the traditional barriers

to ‘opinion’ testimony.” Daubert v. Merrell Dow Pharms., Inc.,

509 US 579, 125 L Ed 2d 469 (1993). In the aftermath of

the adoption of the federal rules, courts were mixed in their

interpretations about whether they conflicted with or could

exist alongside the Frye standard.

Nine years after the passage of the federal rules, this

court changed Oregon’s standards for the admission of scien-

tific evidence and expert testimony in Brown, 297 Or at 438.

This court “rejected the Frye standard of ‘general acceptance

in the scientific community’ as an unnecessarily rigid con-

cept” in determining the admissibility of scientific evidence.

Id. We defined “[t]he term ‘scientific’ * * * [as] evidence that

draws its convincing force from some principle of science,

mathematics and the like.” Id. at 407. We then established

seven factors to be “used in connection with the definition of

‘relevancy’ as defined in OEC 401 and to be utilized in deter-

mining the helpfulness test for expert testimony expressed

in OEC 702.” Id. at 438. General acceptance in the relevant

scientific community—the key determination in the Frye

test—was made to be “one of seven factors to be considered

in determining the relevancy of scientific evidence.”2 Id. at

417. Once a trial court establishes that the scientific evidence

2

Specifically, in Brown, we stated:

“To determine the relevance or probative value of proffered scientific evi-

dence under OEC 401 and OEC 702, the following seven factors are to be

considered as guidelines:

“(1) The technique’s general acceptance in the field;

“(2) The expert’s qualifications and stature;

“(3) The use which has been made of the technique;

“(4) The potential rate of error;

“(5) The existence of specialized literature;

“(6) The novelty of the invention; and

“(7) The extent to which the technique relies on the subjective interpre-

tation of the expert.”

297 Or at 417.

Cite as 372 Or 658 (2024) 685

is relevant, it can move to the second step in determining

the admissibility of scientific evidence; the second step is to

decide if the evidence’s “probative value is substantially out-

weighed by the danger of unfair prejudice, confusion of the

issues, or misleading the jury, or by considerations of undue

delay or needless presentation of cumulative evidence.” Id.

The framework of Brown is still in place today. However, this

court updated that framework in State v. O’Key, 321 Or 285,

899 P2d 663 (1995), which I discuss further below.

Federally, the Frye test was overruled 70 years after

it was initially established, in Daubert. The Court adopted

a more “relax[ed]” and “liberal” standard derived from the

Federal Rules of Evidence. Daubert, 509 US at 580. In con-

trast to the Frye standard, the rules do not give “any indica-

tion that ‘general acceptance’ [was] a necessary precondition

to the admissibility of scientific evidence.” Id. Instead, the

Court established that the rules “place appropriate limits

on the admissibility of purportedly scientific evidence by

assigning to the trial judge the task of ensuring that an

expert’s testimony both rests on a reliable foundation and is

relevant to the task at hand.” Id. at 579-80.

In Kumho Tire Co. v. Carmichael, 526 US 137, 119

S Ct 1167, 143 L Ed 2d 238 (1999), the Court expanded

the applicability of Daubert; the court “conclude[d] that

Daubert’s general holding—setting forth the trial judge’s

general ‘gatekeeping’ obligation—applies not only to testi-

mony based on ‘scientific’ knowledge, but also to testimony

based on ‘technical’ and ‘other specialized’ knowledge.” 526

US at 141. And, as Justice Scalia made clear in his concur-

rence, a trial court’s discretion under Daubert was only as to

“choosing the manner of testing expert reliability[,] * * * not

discretion to abandon the gatekeeping function. * * * [I]t is

not discretion to perform the function inadequately. Rather,

it is discretion to choose among reasonable means of exclud-

ing expertise that is fausse and science that is junky.” Id. at

158-59 (Scalia, J., concurring).

Daubert fundamentally changed federal trial court

judges’ evidentiary responsibilities, requiring them to take

on an enhanced gatekeeping role in deciding whether to

admit scientific evidence. Prior to Daubert—and under the

686 State v. Ortiz

Frye test—trial court judges took a more neutral role in

determining the validity of scientific evidence. Instead of

trial judges evaluating the legitimacy of scientific evidence,

the relevant scientific community was charged with accept-

ing or denying the accuracy of evidence. Judges under Frye

were simply asked to evaluate whether the scientific evi-

dence had been sufficiently accepted by that community.

Now, under Daubert, trial court judges must “act as

evidentiary gatekeepers” to ensure that scientific evidence is

relevant and valid and does not detract from the fairness of

the trial by “mak[ing] a preliminary assessment of whether

the testimony’s underlying reasoning or methodology is sci-

entifically valid and properly can be applied to the facts at

issue.” Daubert, 509 US at 580. This enhanced gatekeep-

ing role of trial courts is widely recognized. As one scholar

noted, Daubert “require[es] judges to evaluate the science in

scientific evidence” and “makes judges responsible for the

validity of the evidence in their courtrooms.” Erica Beecher-

Monas, Blinded by Science: How Judges Avoid the Science

in Scientific Evidence, 71 Temp L Rev 55 (1998). Professor

Beecher-Monas continues:

“The first prong of the Court’s analysis thus requires

judges to critique scientific evidence and separate the

wheat of valid scientific methodology from the chaff of chi-

canery. * * *

“* * * * *

“According to the Supreme Court, the judge must be

able to examine the logic behind the expert’s proffered

testimony without taking sides on its outcome. Not the

expert’s conclusions, but the principles and methodology

underlying the proposed testimony are to be the object of

judicial scrutiny.”

Id. at 62-63 (footnotes omitted; emphasis added).

Other scholars have reached similar conclusions:

“Daubert clearly establishes that trial judges must eval-

uate expert scientific testimony ‘at the outset,’ and that

their analysis should focus on whether the testimony con-

stitutes ‘scientific knowledge that... will assist the trier of

fact to understand or determine a fact in issue.’ Justice

Cite as 372 Or 658 (2024) 687

Blackmun’s opinion requires [courts] to undertake ‘a pre-

liminary assessment of whether the reasoning or method-

ology underlying the testimony is scientifically valid and

of whether that reasoning or methodology properly can be

applied to the facts in issue[.]’ * * *

“* * * * *

“Properly applied, the Daubert test should mean a deeper

and more detailed preliminary review of scientific claims

than most courts have heretofore undertaken.”

Bert Black et al., Science and the Law in the Wake of Daubert:

A New Search for Scientific Knowledge, 72 Tex Law Rev 715,

721 (1994) (footnotes omitted); see also, Sophia I. Gatowski

et al, Asking the Gatekeepers: A National Survey of Judges on

Judging Expert Evidence in a Post-Daubert World, 25 Law

and Hum Behav 433, 436 (2001) (“In Daubert, the Court

explicitly placed judges in the role of ‘gatekeepers’ who eval-

uate the scientific validity and reliability of scientific evi-

dence * * * Daubert’s central premise is that judges can, and

must, decide whether proffered scientific testimony is based

on the scientific method without taking a position regarding

the veracity of particular scientific conclusions.”); Edward

K. Cheng & Albert H. Yoon, Does Frye or Daubert Matter

- A Study of Scientific Admissibility Standards, 91 Va Law

Rev 471, 472 (2005) (Stating that “the enduring legacy of the

Daubert” is that it requires “judges to scrutinize scientific

evidence more closely.”)

After the United States Supreme Court issued

Daubert, this court adopted a similar rule for admitting

scientific evidence in O’Key. In O’Key, this court noted that

FRE 702, which the Supreme Court had used as the basis for

Daubert, “is identical to OEC 702.” 321 Or at 292. Based on

that, we stated that the “decisional process to be applied for

admission and exclusion of scientific evidence articulated in

Daubert is, in our view, an appropriate further development

of the decisional process that we first discussed in Brown.”

Id. at 306. Therefore, we specified that “an Oregon trial

court, in performing its vital role as ‘gatekeeper’ pursuant

to OEC 104(1), should, therefore, find Daubert instructive.”

Id. at 306-07.

688 State v. Ortiz

Importantly, we made clear that the enhanced

gatekeeping role of Oregon courts faced with proffered sci-

entific evidence was mandatory. As we stated, drawing from

Daubert, courts “faced with a proffer of expert scientific

testimony, must determine at the outset, pursuant to FRE

104(a), whether the proposed evidence is based on scientifi-

cally valid principles and is pertinent to the issue to which

it is directed.” Id. at 302-03 (emphasis added).

We recently reaffirmed the active, not passive,

role Oregon courts play in screening scientific evidence in

Marcum v. Adventist Health, 345 Or 237, 244, 193 P3d 1

(2008). There, we held that:

“In ruling on admissibility, the trial court performs the

‘vital role’ of ‘gatekeeper,’ screening proffered scientific

testimony to determine whether it is sufficiently valid, as

a matter of science, to legitimately assist the trier of fact

and ‘exclud[ing] ‘bad science’ in order to control the flow

of confusing, misleading, erroneous, prejudicial, or useless

information to the trier of fact.’ ”

Id. (brackets in Marcum; internal citation omitted).

In light of Daubert and O’Key, the active role the trial

court plays in screening scientific evidence changes some of

the fundamental assumptions of how, and when, a trial court

should involve itself in evidentiary matters, despite the fail-

ure to object by the parties. In my view, this, in turn, changes

some of the fundamental assumptions about the propriety of

exercising discretion to correct unpreserved error on appeal.

In Ailes we noted that exercising discretion to correct plain

error “is contrary to the strong policies requiring preserva-

tion and raising of error.” Ailes, 312 Or at 382. This is true,

but there is an equally strong countervailing policy of the

court’s obligation to gatekeep the admission of scientific evi-

dence in Oregon, regardless of the parties’ objections.

Similarly, in Ailes, we noted that exercising discre-

tion to correct plain error “undercuts the established manner

in which an appellate court ordinarily considers an issue, i.e.,

through competing arguments of adversary parties with an

opportunity to submit both written and oral arguments to

the court.” Id. But, again, in the context of scientific evidence,

Daubert and O’Key require the gatekeeping function of courts

Cite as 372 Or 658 (2024) 689

be conducted regardless of the parties’ objections. Daubert

and O’Key charge courts, not parties, with ensuring valid sci-

ence, and only valid science that is relevant and helpful to

the jury, enters the courtroom. Litigants in Oregon cannot

consent to infect Oregon trials with junk science, quackery,

or any evidence that seeks the imprimatur of science in the

eyes of the jury without an adequate foundation that the evi-

dence has first been subjected to rigors of the scientific pro-

cess. Because of this, exercising discretion to correct plain

error involving scientific evidence does not “undercut[ ] the

established manner” of things, at least to the same degree, as

might be present when an appellate court exercising discre-

tion to reverse unpreserved nonscientific evidentiary error.

This is not to say that an appellate court must correct

unpreserved evidentiary errors involving scientific evidence;

far from it. The discretion to correct unpreserved error under

the second prong of Ailes is just that—discretion. “Discretion”

refers to the authority of a trial court to choose among sev-

eral legally correct outcomes. State v. Rogers, 330 Or 282, 312,

4 P3d 1261 (2000). However, to be properly exercised, discre-

tion must flow from a correct legal premise. See, e.g., State v.

Mayfield, 302 Or 631, 645, 733 P2d 438 (1987). Further, in

exercising discretion, a court can err if it “fails to exercise

discretion, refuses to exercise discretion[,] or fails to make a

record which [sufficiently supports] an exercise of discretion”

Id. This case is an example of a record failure as to the rea-

sons articulated in support of discretion. Accordingly, I have

chosen to write separately in this case because, in my view,

considering the nature of a trial court’s role in gatekeeping

scientific evidence adds a nuance to the legal premises under-

lying Ailes discretion, and may affect how an appellate court

chooses to articulate its reasons for exercising, or not exercis-

ing, that discretion. These musings may, or may not, be taken

up by the Court of Appeals on remand. But they ultimately do

not change how we must dispose of this case. I indicated at the

beginning the reasoning provided by the Court of Appeals in

this case was flawed. The majority correctly reverses on that

basis, and I therefore respectfully concur.

Masih, J., joins in this concurring opinion, and

Duncan, J., joins in this concurring opinion through “Part I.”