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.

, 

 (2023).
Cite as 

 (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, 

, 

 (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.
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         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.
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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,

.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, 

, 

 (1984), and State v.
O’Key, 

, 

 (1995), before the
evidence could be admitted.7 Ortiz, 

.
     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. 

. 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.” 

.
         The court explained that, under Ailes v. Portland
Meadows, Inc., 

, 

 (1991),
plain-error review “involves a two-step inquiry[.]” Ortiz, 

. The court must “first determine whether the
error is plain, and second, [decide] whether to exercise [its]
discretion to consider the error.” 

 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.’ ” 

 (quoting State v. Vanornum, 

, 

 (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.” 

 at 139 (citing State v. Beltran-
Chavez, 

, 

 (2017); State v.
Eatinger, 

, 

 (2019); and State v.
Reid, 

, 

 (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,

. 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.” 

. 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, 

 (citing Brown, 

). That nonexclusive list
is not intended “to be taken as a mechanical checklist of foundational require-
ments.” Id. at 300.
Cite as 

 (2024)                                   665

evidence.” 

 Thus, the court concluded that the error “was
not harmless.” 

        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, 

,

 (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.” 

 (citing Ailes, 

). Second, we consider whether the Court of Appeals
abused its discretion in reversing based on that error. 

 If
the Court of Appeals exercises its discretion to reverse on
plain-error review, it “must articulate its reasons for doing
so.” Ailes, 

.
         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[.]” 

n 6. Those factors “do not comprise a necessary or complete
checklist; they merely are some of the permissible consider-
ations.” 

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, 

, 

 (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, 

 (quoting Ailes, 

); see
also Vanornum, 

 (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, 

 (quoting Hotelling v.
Walther, 

, 

 (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, 

, 

 (2022); see also Vanornum, 

 (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.” 

.
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. 

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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[.]” 

.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, 

. In 1981, another SCRI
study for NHTSA standardized the procedures for admin-
istering and scoring those FSTs. 

.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. 

 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.” 

. 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.” 

 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. 

.
    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, 

 (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. 

 (citing State v. Clark, 

, 

 (1979) (internal quotation marks
omitted)).11
        We further discussed the walk-and-turn and one-
leg-stand tests in State v. Mazzola, 

, 

 (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.”

 at 818 (quoting United States v. Horn, 

 (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.” 

         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. 

.
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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,

.
         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, 

, 

 (2003). We acknowledge that, by
invoking “the vocabulary of scientific research,” 

,
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, 

, 

 (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[.]” 

. Similarly,
in State v. Ramirez, 

, 

 (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.” 

. 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.” 

.
        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.
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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, 

. 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, 

.
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, 

, 

 (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, 

.
    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, 

. 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, 

, 

 (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, 

, 

, rev den, 

 (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, 

, 

 (1990). Ailes,

. 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.” 

. 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.” 

. 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 

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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, 

, 

 (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.” 

.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, 

n 6 (citing Brown, 

, and Avent, 

). 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, 

, 

 (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. 

. 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. 

. 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. 

.
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, 

, 

 (1975)—
and concluding, without further explanation, that the Court
of Appeals had “erred in reaching defendant’s confrontation
argument.” Jensen, 

.
         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.” 

.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, 

, 

 (1965), and State v. Rupp, 

, 

 (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.”

. In Rupp, this court declined to review an instructional error for the
same reason. 

.
Cite as 

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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.” 

. 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.” 

 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.” 

 at 630-31 (citing Ailes, 

).
         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, 

, 

 (2000), cert den, 

 (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, 

, 

 (2015)
(en banc), rev den, 

 (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. 

(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, 

, and
in Vanornum, 

, 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 

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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.” 

 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, 

, 

 (2023). There, the
court first concluded that the instructional error “was not
legally ‘harmless[.]’ ” 

. That meant only that the court
“ha[s] discretion to correct the error, if [it] so choose[s][.]” 

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.” 

 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. 

 (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. 

.
          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 

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           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.,

, 

 (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,

, 

 (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, 

, 

, 

 (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 

(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, 

 (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.” 

. In State
v. Henley, 

, 

 (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,

, 

 (2017), State v. Eatinger,

, 632, 

 (2019), and State v. Reid,

, 

 (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 

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   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, 

.
         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. 

.
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.”

 (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. 

.
         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, 

. 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 

 (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, 

, 

 (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.,

, 

 (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, 

.
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.

 We defined “[t]he term ‘scientific’ * * * [as] evidence that
draws its convincing force from some principle of science,
mathematics and the like.” 

. 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.” 

. 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 

. 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.”

.
Cite as 

 (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.” 

The framework of Brown is still in place today. However, this
court updated that framework in State v. O’Key, 

,

 (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, 

. 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.” 

 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.” 

.
          In Kumho Tire Co. v. Carmichael, 

, 

, 

 (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.” 

. 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.” 

 (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, 

. 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 

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   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.” 

. 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.”

. 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.”

.
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.” 

 (emphasis added).
         We recently reaffirmed the active, not passive,
role Oregon courts play in screening scientific evidence in
Marcum v. Adventist Health, 

, 

(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.’ ”

 (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, 

. 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.” 

 But, again, in the context of scientific evidence,
Daubert and O’Key require the gatekeeping function of courts
Cite as 

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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, 

,

 (2000). However, to be properly exercised, discre-
tion must flow from a correct legal premise. See, e.g., State v.
Mayfield, 

, 

 (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”

 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.”