No. 51	                      December 3, 2015	325

              IN THE SUPREME COURT OF THE
                    STATE OF OREGON

                        STATE OF OREGON,
                        Plaintiff-Respondent,
                                  v.
                       ISACC CREED AGEE,
                        Defendant-Appellant.
                     (CC 09C41224; SC S059530)

    En Banc
   On automatic and direct review of the judgment of con-
viction and sentence of death imposed by Marion County
Circuit Court.
    Pamela L. Abernethy, Judge.
    Argued and submitted on April 22, 2015.
   Ryan T. O’Connor, O’Connor Weber LLP, Portland,
argued the cause and filed the briefs for petitioner. With him
on the briefs was Kenneth A. Kreuscher.
   Timothy A. Sylwester, Attorney General, Salem, argued
the cause and filed the brief for respondent. With him on the
brief were Ellen F. Rosenblum, Attorney General, Anna M.
Joyce, Solicitor General, and Susan G. Howe and Michael S.
Shin, Assistant Attorneys General.	
    BALMER, C. J.
   The judgment of conviction is affirmed. The sentence of
death is vacated, and the case is remanded to the circuit
court for further proceedings.
    Case Summary: Defendant, an inmate as Oregon State Penitentiary, together
with another inmate, killed a third inmate; he was convicted of aggravated mur-
der and sentenced to death. On automatic and direct review, defendant sought
reversal of his conviction and sentence of death. Held: (1) The trial court erred
in permitting the prosecutor extensively to cross-examine a key defense witness
outside the presence of the jury, but that error was harmless; (2) the trial court
erred at a pretrial hearing to determine defendant’s eligibility for the death pen-
alty when it used an inappropriate standard for determining that defendant had
not met his burden of proving intellectual disability, and that that error required
remand for a new hearing to determine defendant’s eligibility for the death pen-
alty; (3) the trial court erred when it refused to permit the defendant’s experts
326	                                                            State v. Agee

to testify during the penalty phase proceeding that they had diagnosed him as
intellectually disabled, and that that error was not harmless; (4) the trial court
did not err during the penalty phase when it declined to instruct the jury that it
must determine whether defendant was intellectually disabled; and (5) the trial
court erred during the penalty phase when it excluded evidence that defendant’s
co-defendant received a life sentence for his role in the victim’s murder, and that
error was not harmless. The judgment of conviction is affirmed.
    The sentence of death is vacated, and the case is remanded to the circuit
court for further proceedings.
Cite as 358 Or 325 (2015)	327

	         BALMER, C. J.
	         This case is before us on automatic and direct review
of defendant’s judgment of conviction and sentence of death
for aggravated murder. ORS 138.012(1). For the reasons
that follow, we affirm the judgment of conviction, vacate the
sentence of death, and remand this case to the circuit court
for further proceedings.
                      I. BACKGROUND
	         We begin with an overview of relevant facts; we
describe additional facts in our discussion of defendant’s
assignments of error. Because the jury found defendant
guilty, we view the evidence presented at trial in the light
most favorable to the state. State v. Washington, 355 Or 612,
614, 330 P3d 596 (2014).
	         In May 2005, defendant arrived at the Oregon
State Penitentiary to begin serving a 40-year sentence for
attempted murder and other offenses. In February 2008,
defendant and his cell-mate, Davenport, entered the cell of a
third inmate, the victim, when the doors to all the cells in the
area were opened to permit the inmates to go to breakfast.
Both defendant and Davenport were wearing gloves and were
armed. Defendant had a seven-inch-long shank with a half-
inch piece of sharpened metal on the end, sheathed in the
plastic casing of a highlighter pen. Davenport was carrying a
mesh laundry bag containing an almost four-pound piece of
concrete wrapped in a stocking cap. The door to the cell closed
after about 30 seconds, locking defendant and Davenport in
the cell with the victim. Davenport began striking the victim
in the head with the concrete block. Defendant stabbed the
victim in the legs and torso 28 times with the shank.
	         A corrections officer heard panting and investi-
gated. He saw two inmates standing in the cell, out of breath,
and another on the ground; he yelled to another corrections
officer for help. The two corrections officers saw Davenport
standing in the back of the cell near the victim’s head and
defendant standing to the side of the cell, near the victim’s
torso and legs and next to a table in the cell. While the offi-
cers waited for other guards to arrive (to enable them safely
to open the cell door), they saw Davenport strike the victim
in the head about 20 times with the concrete block, and saw
328	                                                          State v. Agee

defendant kick the victim in the ribs and punch him in the
chest with a closed fist. Defendant walked to the cell door
and submitted to wrist restraints as Davenport continued to
strike the victim’s head with the concrete block. Davenport
also eventually submitted to restraints. Officers removed
Davenport and defendant from the cell and a nurse con-
firmed that the victim was dead. While defendant was being
escorted from the scene, a corrections officer asked him
whether he was in possession of any weapons. Defendant
responded no, he had left his weapon on the table in the
cell. The shank was later found on the table. According to
the state medical examiner, the victim died from the blows
to the head with the concrete block. The shank caused only
superficial wounds.
	        Defendant and Davenport were jointly charged with
aggravated murder for the intentional homicide of a prison
inmate by another inmate. ORS 163.095(2)(b) (defining
aggravated murder as murder committed when defendant
was confined in a correctional facility at time that murder
occurred). The state declared its intention to seek the death
penalty for both defendants. After Davenport provided the
state with evidence of his mental incapacity dating back to
his early teen years, the state conceded that Davenport was
“mentally retarded”1 and therefore ineligible for the death
penalty under the controlling United States Supreme Court
case, Atkins v. Virginia, 536 US 304, 321, 122 S Ct 2242,
153 L Ed 2d 335 (2002) (holding that execution of “men-
tally retarded” persons violates Eighth Amendment’s ban
on cruel and unusual punishment). Davenport subsequently
pleaded guilty and was sentenced to life in prison without
the possibility of parole.
	        Defendant also moved the trial court to declare him
intellectually disabled and ineligible for the death penalty,
but the state did not concede the issue as to him. Because,
as we discuss in more detail below, there are no specific

	1
       At the time of defendant’s trial, the terms “mental retardation” and “men-
tally retarded” were in common usage in court opinions and in the medical lit-
erature. The mental health community now agrees that the preferred clinical
terms are “intellectual disability” and “intellectually disabled.” Throughout the
remainder of this opinion, therefore, we use those terms unless we are directly
referring to a source that uses one of the now-disfavored terms.
Cite as 358 Or 325 (2015)	329

procedural or substantive guidelines in Oregon for deter-
mining when a defendant is ineligible for the death penalty
under the general holdings of Atkins, the trial court deter-
mined that it would conduct a pretrial hearing at which
defendant would have the burden of proving that he is
intellectually disabled by a preponderance of the evidence.
Defendant acceded to that procedure.2
	         In an April 2011 hearing, both the state and defen-
dant offered evidence from psychologists and psychiatrists
concerning defendant’s mental health and intellectual abili-
ties. The trial court found that defendant suffered from par-
tial fetal alcohol syndrome but concluded that defendant had
not established an intellectual disability that would make
him constitutionally ineligible for the death penalty. In May
2011, a jury was empanelled and, after a guilt-phase trial,
the jury found defendant guilty of aggravated murder. At
the conclusion of a further, penalty-phase proceeding under
ORS 163.150, the jury determined that defendant had acted
deliberately in committing the murders, that he posed a con-
tinuing risk to society, and that he should receive a death
sentence. ORS 163.150(1)(b)(A), (B), (D). The trial judge
then entered a sentence of death. This automatic and direct
review followed.
                  II.  ASSIGNMENTS OF ERROR
	       On review before this court, defendant raises 29
assignments of error. We have reviewed all those assign-
ments of error and conclude that many of them are not well
taken and do not merit further discussion.3 We address
defendant’s remaining assignments of error below.

	2
      In fact, defendant suggested that procedure in a brief to the trial court
outlining the various ways that other states have handled similar situations.
	3
       With respect to several of the assignments of error that we do not address—
those relating to (1) the trial court’s admission, during the guilt phase, of an
audio recording of a telephone conversation between defendant’s mother and
his incarcerated brother; (2) the trial court’s admission, during the guilt phase,
of two pieces of paper found after the murder in defendant’s prison cell among
defendant’s other property; and (3) the trial court’s imposition of a death sentence
notwithstanding defendant’s argument that the jury was not given proper accom-
plice liability instructions—we conclude either that the error was not preserved
or that the trial court did not err. The others have been answered adversely to
defendant’s position in prior decisions by this court, and, therefore, further dis-
cussion will not benefit the public, the bench, or the bar.
330	                                                          State v. Agee

	       We discuss five assignments of error. Only one
assignment of error concerns a ruling made during the guilt
phase; we begin there.
A.  The Trial Court’s Decision to Permit Extensive Cross-
    Examination of Codefendant Outside Presence of Jury
	        At defendant’s trial, after the completion of jury
selection but prior to the jury being sworn, the trial court
and both parties called to the stand eight inmates for the
limited purpose of inquiring whether the inmates intended
to invoke their privileges against self-incrimination if called
as witnesses in front of the jury. One of those witnesses was
Davenport. The trial court swore in Davenport and defendant
conducted a limited examination about whether Davenport
was willing to testify about the events on the day that the
victim was killed and Davenport’s involvement with a par-
ticular prison gang.4 Defense counsel asked and received
answers to the following questions: whether Davenport
understood that he would be asked about the events sur-
rounding the murder and his involvement with the gang,
whether Davenport would testify about those things, and
whether he would invoke his Fifth Amendment privileges.
	        On cross-examination, after confirming that
Davenport would testify about the events of the day of
the murder, the prosecutor asked whether Davenport was
prepared to testify about what happened during the week
before the murder. Davenport initially responded that noth-
ing had happened the week before. The prosecutor then
asked Davenport if he was a “gangster.” Davenport replied
that he would not answer that question, but would testify
about his involvement in the murder and exactly what hap-
pened that day. The prosecutor told Davenport that he was
required to answer any question that was put to him and
again asked whether Davenport was a gangster. Davenport

	4
       Part of the defense theory was that Davenport was a member of a prison
gang and wanted to kill the victim because the gang leadership had directed that
the victim be killed. Defendant’s theory was that he went along with Davenport
because he was Davenport’s childhood friend and a “follower,” even though he
was not a member of the gang. Davenport’s testimony supported that theory:
Davenport maintained that he alone was the mastermind and executor of the
murder and that defendant was merely a spectator whom Davenport had goaded
into accompanying him into the victim’s cell.
Cite as 358 Or 325 (2015)	331

continued to refuse to answer that question, and defense
counsel began to object. The prosecutor interrupted the
defense objection to complain to the judge that, if Davenport
were not willing to answer the prosecutor’s questions,
he should not be allowed to testify at the trial at all. The
court then conducted a colloquy with Davenport in which
Davenport agreed to answer questions from both parties if
he were called as a witness. The court directed the prose-
cutor to ask again about Davenport’s gang involvement, to
“test” Davenport’s willingness to cooperate. The prosecutor
posed multiple questions about Davenport’s gang member-
ship, his gang tattoos, his relationship with various gang
members, his knowledge of the gang’s power structure, and
the role of the gang in the murder. During that questioning,
Davenport at first attempted to avoid giving direct, truthful
answers, even though the court reminded him several times
that this was a “test run” to determine if he would cooper-
ate with cross-examination. Davenport eventually began to
answer the prosecutor’s questions, although he frequently
answered, “I don’t know.” From there, the prosecutor moved
on to questions about Davenport’s relationship with defen-
dant, which Davenport answered directly.
	        The prosecutor then began asking Davenport spe-
cific and detailed questions about his and defendant’s actions
on the day of the murder:
   	 “[PROSECUTOR]:  And on the 14th, you keep saying
   that you’re the one that did the killing.
   	   “[DAVENPORT]:  Yes, I did.
   	   “[PROSECTUTOR]:  What weapons did you use?
   	   “[DAVENPORT]:  I used a knife and a chunk of cement.
   	   “[PROSECUTOR]:  Okay. Where was the defendant?”
Defendant objected for a second time, arguing that
Davenport had made clear that he would answer questions
about the day of the murder. The trial court overruled the
objection and allowed the prosecutor to continue examining
Davenport. The prosecutor resumed asking Davenport ques-
tions about his and defendant’s actions during the murder,
including asking leading questions to draw out a moment-
by-moment description of defendant’s and Davenport’s
332	                                            State v. Agee

actions and statements leading up to and during the assault
on the victim, and including eliciting testimony about how
Davenport coerced defendant into entering the victim’s cell.
	        Defense counsel raised a third objection, noting that
the purpose of the hearing was limited to an inquiry about
whether the inmate witnesses would be invoking their Fifth
Amendment right not to testify. Defendant conceded that
the prosecutor had had reason to ensure that Davenport
would testify about his gang involvement and who ordered
the murder, but he argued that this was not an opportunity
for a pretrial deposition about the murder; Davenport had
no arguable Fifth Amendment right not to testify about the
murder itself and, therefore, the prosecutor should not be
allowed effectively to depose him on that topic at that hear-
ing. The prosecutor responded that “[t]his is not about him
taking the Fifth.” Rather, the prosecutor argued, the issue
was whether Davenport would answer the state’s questions.
The prosecutor argued that he should be permitted to deter-
mine whether Davenport would “talk through the incident
in its entirety,” and, if not, then his testimony should not
be allowed. The trial court overruled defendant’s objection
and directed the prosecutor to continue, which he did, in the
same vein as earlier, questioning Davenport in detail about
his and defendant’s roles in the murder, his and defendant’s
statements during the murder, and what information defen-
dant would have known prior to the murder.
	        Defendant argues in this court that, generally, trial
courts do not have authority to compel a criminal witness
to be deposed or give pretrial testimony outside the pres-
ence of the jury. See State ex rel O’Leary v. Lowe, 307 Or
395, 401-02, 769 P2d 188 (1989) (issuing writ of mandamus
directing trial court to withdraw order requiring prosecu-
tor to produce some of state’s criminal witnesses for pretrial
deposition by defendant, holding that “[t]here is no statu-
tory right in Oregon for a criminal defendant to depose a
potential state’s witness”). Although O’Leary involved a
defendant’s effort to compel pretrial testimony from a state
witness, defendant argues that the same rule would apply
to the prosecution. Defendant acknowledges the trial court’s
authority to permit examination of a witness outside the
presence of the jury for purposes of trial management, but
Cite as 358 Or 325 (2015)	333

he argues that, under O’Leary, trial courts have no author-
ity to compel a defendant or a witness in a criminal trial to
submit to pretrial depositions. Defendant contends that the
holding in O’Leary is consistent with ORS 136.420, which
precludes (with two exceptions not relevant here) any form
of “testimony,” including depositions, in a criminal case,
other than oral testimony in the presence of the court and
jury.5 Defendant argues that the pretrial examination and
deposition of Davenport allowed the prosecution to conduct
essentially full discovery of Davenport, under oath and out-
side the presence of the jury, and that it is hard to overstate
the utility of that sort of prior opportunity to question a cen-
tral defense witness.
	         Trial courts have explicit and inherent authority to
control courtroom proceedings. See State v. Mains, 295 Or
640, 656, 669 P2d 1112 (1983) (so stating); ORS 1.010 (every
court has power to regulate proceedings before it and to con-
trol, in furtherance of justice, conduct of persons connected
with judicial proceedings); OEC 611(1) (court shall exercise
reasonable control over presentation of evidence); see also
ORS 135.037(3) (providing for omnibus pretrial hearings
where trial court “may also consider any matters that will
facilitate trial by avoiding unnecessary proof or by simpli-
fying the issues to be tried, or that are otherwise appropri-
ate under the circumstances to facilitate disposition of the
proceeding”). Moreover, a trial court has broad discretion
when exercising its authority to control the presentation of
evidence.6 State v. Cox, 337 Or 477, 495, 98 P3d 1103 (2004)
(trial court had authority to strike from record entirety of
	5
        ORS 136.420 provides:
    	     “In a criminal action, the testimony of a witness shall be given orally in
    the presence of the court and jury, except:
    	     “(1)  In the case of a witness whose testimony is taken by deposition by
    order of the court in pursuance of the consent of the parties, as provided in
    ORS 136.080 to 136.100 [providing that trial court may require, as precondi-
    tion for granting postponement of trial, requesting party’s consent to deposi-
    tions of its witnesses]; or
    	 “(2) As provided in ORS 131.045 [permitting court appearances by
    simultaneous electronic transmission].”
	6
        Exercising control over the presentation of evidence helps to reduce verbal
conflicts between counsel, to eliminate “speaking” objections, to prevent abuse
or harassment of witnesses during questioning, to restrict closing arguments to
legal limits, and to avert error. Mains, 295 Or at 656.
334	                                            State v. Agee

defendant’s trial testimony after he refused to answer three
questions posed to him by the state on cross-examination);
see also State v. Rogers, 330 Or 282, 302, 4 P3d 1261 (2000)
(Rogers I) (trial court has authority to pre-approve contents
of aggravated murder defendant’s allocution statement).
	         However, although the trial court’s discretion is
broad, it is limited by the rules governing the conduct of the
trial. In a criminal prosecution, the trial court may not per-
mit either party to conduct pretrial examination of witnesses
except in certain limited circumstances. For example, the
statutes governing pretrial discovery in criminal matters do
not permit either the defendant or the state to take pretrial
depositions. ORS 135.805 to 135.873 (setting out rules for
pretrial discovery in criminal prosecutions). Moreover, ORS
136.420 provides that, in a criminal trial, after the jury is
sworn, all testimony “shall be given orally in the presence
of the court and jury,” except in certain circumstances not
relevant here. This court has held that that statute “ ‘was
intended to make the general rule, concerning the taking
of depositions, inapplicable to criminal trials.’ ” State v.
Lamphere, 233 Or 330, 332-33, 378 P2d 706 (1963) (quoting
State v. Walton, 53 Or 557, 565, 99 P 431 (1909)) (referring
to virtually identically worded earlier version of statute);
State ex rel Gladden v. Lonergan, 201 Or 163, 181, 269 P2d
491 (1954) (to same effect). In this case, as we shall explain,
we conclude that the trial court, in permitting the prose-
cutor to question Davenport extensively about the events
surrounding the murder, exceeded its discretion to manage
courtroom proceedings, and, instead, effectively permitted
an unlawful pretrial deposition of a defense witness.
	        As noted, after the jury was selected in this case
but before it was sworn, the trial court conducted a hearing,
the stated purpose of which was to determine whether cer-
tain witnesses would testify at trial. It is indisputable that
it was within the trial court’s discretion to determine, at
that point, whether the witnesses would testify, including
whether the witnesses would respond to questions from both
defense counsel and the prosecutor, and to do so by permit-
ting the prosecutor to question the witnesses. Although the
trial court later would have the option of excluding some or
all of a witness’s testimony if the witness refused to answer
Cite as 358 Or 325 (2015)	335

the prosecutor’s questions at trial, Cox, 337 Or at 493, the
court reasonably could have concluded that permitting the
prosecutor to question the witness at the hearing to test the
witness’s compliance was preferable to that course of action.
However, with respect to Davenport, the trial court went
well beyond simply determining whether the witness would
testify. Before the prosecutor started to question Davenport
about the events surrounding the murder, Davenport had
stated under oath that he would testify about those events,
and he had amply demonstrated that he would answer the
prosecutor’s questions.
	        It is true that Davenport initially resisted answer-
ing questions about his relationship with a certain prison
gang, but he did eventually answer all of the prosecutor’s
questions on that topic, and he had appropriately answered
questions about his relationship with defendant. At the
point when defense counsel interposed his second objection
to the prosecutor’s questions, Davenport also had answered
several questions about the murder itself. At that point,
requiring Davenport to answer questions from the prose-
cutor that essentially revealed the entirety of Davenport’s
substantive testimony about defendant’s participation in
the murder exceeded the legitimate purpose of the hearing.
The prosecutor’s continued questioning of Davenport con-
stituted, in essence, a pretrial deposition—the sort of dis-
covery that is not permitted under the statutes governing
pretrial discovery in criminal matters and that is prohibited
by the requirement in ORS 136.420 that all testimony “shall
be given orally in the presence of the court and jury.” We
conclude, therefore, that the trial court erred in overruling
defense counsel’s second and third objections to the prose-
cutor’s continued questioning of Davenport about the events
surrounding the murder.
	         As this court has often explained, however, not all
errors require reversal. An error is not a ground for a new
trial if it is harmless—that is, if the court determines that
there is little likelihood that it affected the verdict. State
v. Rogers, 352 Or 510, 543, 288 P3d 544 (2012) (Rogers II).
Defendant argues that the trial court’s decision to allow the
pretrial examination of Davenport was harmful to his case
and likely affected the verdict, because the prosecution was
336	                                            State v. Agee

able to use Davenport’s hearing testimony not only to decide
which questions to ask Davenport, but also to impeach
Davenport with his prior answers when his trial testimony
diverged from his testimony at the hearing. Defendant
argues that Davenport’s credibility was key to the jury’s
determination of defendant’s guilt and that the prosecution
was able to use Davenport’s hearing testimony to under-
mine his credibility.
	        We agree that Davenport’s testimony was central to
the defense case; his testimony, if believed, tended to excul-
pate defendant. However, we are not persuaded that the
prosecutor’s improper pretrial questioning of Davenport had
a significant effect on Davenport’s credibility at trial or was
likely to have affected the verdict.
	        Defendant identifies no significant benefit that the
prosecution gained at trial from improperly cross-examining
Davenport during the pretrial hearing. With respect to the
prosecution’s use of Davenport’s pretrial hearing testimony
to decide which questions to ask him at trial, defendant
argues only that the prosecutor “confidently used previewed
* * * testimony” about Davenport’s relationship with and
knowledge of the gang during extended questioning on that
topic at trial and, in closing, repeatedly urged the jury to
find that Davenport had lied in his responses to that ques-
tioning. However, as described above, the trial court did
not err in permitting questioning about Davenport’s gang
involvement; rather, the error that we have identified relates
to questioning that took place after that line of questioning
concluded. It follows that defendant cannot rely on the prose-
cution’s use of Davenport’s pretrial testimony about his gang
involvement for cross-examination purposes to support an
argument that the trial court committed reversible error.
	        As for the prosecution’s use of Davenport’s pretrial
hearing testimony for impeachment purposes at trial, defen-
dant points to only one instance in which the prosecutor used
Davenport’s hearing testimony to undermine his credibility
at trial. During cross-examination, the prosecutor pointed
out that Davenport had testified at the pretrial hearing
that defendant had had no knowledge of Davenport’s plan
to murder the victim and that defendant had done nothing
Cite as 358 Or 325 (2015)	337

to prepare himself before entering the victim’s cell. But on
direct examination at trial, Davenport testified that both he
and defendant had donned gloves before entering the cell,
which he conceded was a step in preparation for what was
going to happen. The prosecutor focused on that inconsis-
tency to undermine Davenport’s testimony at trial. However,
any damage to Davenport’s credibility from the prosecu-
tor’s ability to draw attention to that one small discrepancy
between Davenport’s hearing testimony and his trial testi-
mony is dwarfed by the fact that much of Davenport’s trial
testimony was contradicted or undermined by other evi-
dence and testimony admitted independently of the prosecu-
tor’s use of Davenport’s hearing testimony for impeachment
purposes.
	         For instance, on direct examination by defendant,
Davenport testified, among other things, that he goaded and
threatened defendant into entering the victim’s cell against
his will; that Davenport and Davenport alone murdered
the victim, using both the concrete block and the shank to
inflict all of the injuries on the victim while defendant cow-
ered and watched; and that defendant knew nothing about
what would happen in the victim’s cell other than that the
victim had offended Davenport and Davenport wanted to
teach the victim a lesson. That story was not plausible, and
it was inconsistent with other testimony and evidence pre-
sented at trial. Specifically, it was undisputed that defen-
dant entered the victim’s cell wearing gloves and that he
did not leave when Davenport began hitting the victim with
the concrete block, even though the cell doors were still open
at that time. Several corrections officers testified that they
saw defendant punching and kicking the victim, and there
was blood on defendant’s gloves and shoes to support that
testimony. And, when defendant was asked by a corrections
officer after the murder whether he was carrying a weapon,
defendant responded that he had left his weapon on a table
in the victim’s cell, where the shank was later found.
	       Similarly, Davenport’s testimony about his gang
involvement was internally inconsistent and in conflict
with the testimony of other witnesses. Davenport admit-
ted that he had been a member of a gang for some time,
that he had been the cellmate of two other gang members,
338	                                                        State v. Agee

and that he had known most of the other gang members
for years. Additionally, another member of the gang testified
about Davenport’s participation in gang activities, including
that Davenport had attended multiple meetings at which
gang leaders talked about having the victim killed and that
Davenport had volunteered to kill the victim. Nonetheless,
at defendant’s trial, Davenport consistently denied knowing
anything about how the gang operated, its power structure,
the nicknames or roles of any the gang’s other members, or
that its leaders wanted the victim murdered.
	        Because defendant has identified no specific testi-
mony from the pretrial hearing that the prosecutor was able
to use in cross-examining Davenport that was not also sup-
ported by other evidence, and because there were other incon-
sistencies in Davenport’s testimony that called his credibil-
ity into question, we conclude that the prosecutor’s improper
cross-examination of Davenport at the pretrial hearing was
not likely to have affected the verdict. We therefore hold that,
although the trial court erred in permitting the prosecutor
to examine Davenport extensively about the murder outside
the presence of the jury, that error was harmless.
	        As previously noted, we have considered the other
assignments of error that defendant claims arose during
the guilt phase and found them to be without merit. Having
found no reversible error during that phase of the trial, we
affirm defendant’s conviction for aggravated murder.
B.  Trial Court’s Ruling that Defendant Is Not Ineligible for
    the Death Penalty Due To Intellectual Disability
	       Three assignments of error relate in some way to
defendant’s contention that he is intellectually disabled. We
begin by addressing defendant’s argument that the trial
court erred in denying, before trial, defendant’s “Motion
Number 20,” in which defendant moved the court for a rul-
ing that he was ineligible for the death penalty because he
was intellectually disabled.7
	7
     After the jury’s penalty-phase verdict, defendant also filed a sentencing
memorandum in which he argued that the verdict did not authorize a death
sentence, because, among other things, it would be unconstitutional to sen-
tence him to death when he had established functional deficits equivalent to,
and in many instances worse than, other individuals who have been deemed
Cite as 358 Or 325 (2015)	339

	         We discuss the law governing defendant’s eligibility
for the death penalty in detail below. To put the descrip-
tion of defendant’s assignments of error in context, how-
ever, it is helpful at this point to explain that, in 2002, the
United States Supreme Court held in Atkins that, in light
of evolving standards of decency, the death penalty is exces-
sive, cruel, and unusual under the Eighth Amendment to
the United States Constitution when applied to intellectu-
ally disabled offenders.8 536 US at 321. The Court explained
that the intellectually disabled should be held responsible
for their crimes and they should be punished for them, but
that, “[b]ecause of their disabilities in areas of reasoning,
judgment, and control of their impulses, * * * they do not act
with the level of moral culpability that characterizes the
most serious adult offenders.” Id. at 306. However, the Court
stated, not all people who claim to be intellectually disabled
“will be so impaired as to fall within the range of mentally
retarded offenders about whom there is a national consen-
sus.” Id. at 317. The Court noted that “clinical definitions
of mental retardation require not only subaverage intellec-
tual functioning, but also significant limitations in adaptive
skills such as communication, self-care, and self-direction
that become manifest before age 18.” Id. at 318. But the
Court declined to set a standard for determining whether an
offender is intellectually disabled or to specify a particular
procedure for making that determination. Rather, the Court
left it to the states to develop “appropriate ways to enforce
intellectually disabled. He argued that, because the court found that he suffered
from partial fetal alcohol syndrome, the Eighth Amendment and the Privileges
and Immunities Clause prohibited his execution, because there is no rational
way to distinguish defendant from those individuals found to be exempt from the
death penalty. Defendant contended that, although his IQ might be higher, he
functions in the real world with the same deficits as, or worse than, individuals
classified as intellectually disabled. Defendant orally renewed that argument
during the sentencing hearing. The trial court sentenced defendant to death
without expressly ruling on or otherwise addressing that particular argument.
In his brief to this court, defendant assigns error to the trial court’s effective
rejection of his argument. However, defendant does not make a separate argu-
ment relating to the trial court’s failure to respond to his post-verdict arguments.
We therefore address that matter in the context of our discussion of the denial of
defendant’s pretrial motion for a ruling that he was ineligible for the death pen-
alty because of his intellectual disability.
	8
       The Eighth Amendment to the United States Constitution provides:
    	 “Excessive bail shall not be required, nor excessive fines imposed, nor
    cruel and unusual punishments inflicted.”
340	                                                             State v. Agee

the constitutional restriction” on executing intellectually
disabled persons. Id. at 317.
	        In 2010, when defendant moved the trial court to
declare him ineligible for the death penalty because of his
intellectual disability, Oregon had not yet developed a way
to enforce the constitutional restriction against executing
intellectually disabled offenders. Indeed, in the years since
the Supreme Court decided Atkins, the Oregon legislature
has not adopted any procedure for determining whether a
person accused of aggravated murder has an intellectual
disability and, therefore, ineligible for the death penalty.
Nor has the issue been addressed by the Oregon appellate
courts before today.9 Lacking such guidance, the trial court
	9
       In fact, although Oregon’s Constitution, like the federal constitution, pro-
hibits cruel and unusual punishment, Or Const Art I, § 16, this court has not
previously announced a categorical prohibition on the execution of persons with
intellectual disabilities. Defendant urges this court to adopt the same standard
under Article I, section 16, that the United States Supreme Court has recognized
for the Eighth Amendment. Defendant, however, having acknowledged that
this court has never announced a categorical ban on the execution of any class
of offenders, does no more than assert that “it stands to reason” that Article I,
section 16, “does contemplate such categorical bans.” That is so, he states,
because the texts of the state and federal constitutional provisions are similar
and this court’s interpretations of Article I, section 16, have generally followed
the Supreme Court’s interpretations of the Eighth Amendment. The state, for
its part, argues that defendant failed to preserve an argument that Article I,
section 16, prohibits the execution of intellectually disabled persons. Because
neither party has made a developed legal argument about the scope of Article I,
section 16, and because the Supreme Court’s Eighth Amendment jurisprudence
clearly prohibits the execution of intellectually disabled persons, we depart from
our normal course—starting our analysis by considering Oregon constitutional
law—and begin instead with the parties’ federal constitutional arguments.
	   Defendant also argues at length that both Article I, section 16, of the Oregon
Constitution and the Eighth Amendment categorically prohibit the execution
of any person with “reduced mental capacity,” whether the person suffers from
“intellectual disability” as that term is defined in the medical literature, or from
partial fetal alcohol syndrome like defendant, or from any condition that simi-
larly reduces the person’s culpability for his or her actions. That is so, defendant
argues, because inflicting the death penalty on such a person does not mean-
ingfully advance the retributive or deterrent purposes of the death penalty. In
response, the state points out that defendant does not define the contours of
“reduced capacity,” other than to suggest that any person who “functions like an
intellectually disabled person” is exempt from the death penalty. In addition, the
state contends, defendant did not make that argument below, and, therefore, it is
not preserved.
	   As discussed in the text, the Supreme Court has held that there is a national
consensus against executing a person with “intellectual disability,” a diagnosis
specifically defined in the medical literature. Assuming for purposes of argument
that the Court’s rationale for categorically exempting intellectually disabled
Cite as 358 Or 325 (2015)	341

in this case invited suggestions from the parties about how
to proceed and ultimately concluded that it would conduct
a pretrial hearing, which we refer to as an Atkins hearing,
during which both sides would present evidence on defen-
dant’s mental health and abilities as well as on the pre-
vailing standards for making the determination of intel-
lectual disability. For defendant to be found intellectually
disabled and, therefore, ineligible for the death penalty, the
trial court ruled, defendant would have to establish that
he was intellectually disabled by a preponderance of the
evidence.
	        At the ensuing hearing, in April 2011, both defen-
dant and the state offered evidence from psychiatrists and
psychologists on defendant’s intellectual functioning. The
evidence at that hearing comprised expert testimony, writ-
ten reports of experts, and documentary evidence of psy-
chological and medical testing of defendant. The parties’
experts all generally agreed on the applicable criteria,10
defendant’s scores on standardized tests, and most of defen-
dant’s diagnoses. They disagreed, however, about how to
apply those criteria in evaluating defendant and about the
significance of the standardized test scores in making the
ultimate determination of whether defendant has an intel-
lectual disability.
	        In 2011, the diagnostic criteria for intellectual dis-
ability, widely accepted and derived from the medical lit-
erature, amounted to a three-pronged inquiry into (1) the
person’s intellectual functioning, (2) the person’s adaptive
behavior (how the person functions in day-to-day life), and
(3) whether the disability manifested before adulthood. That

persons from execution would apply equally to all individuals with intellectual
deficits similar in severity to those required for a diagnosis of intellectual disabil-
ity, the Court has not extended the categorical exemption from the death penalty
to persons with “reduced mental capacity” who do not meet the criteria for a
diagnosis of “intellectual disability.” We therefore decline to consider the issue in
this case.
	10
         Both the defense and prosecution relied extensively on two manuals that
provide diagnostic criteria for intellectual disability: the Fourth Edition (text
revision) of the American Psychiatric Association’s Diagnostic and Statistical
Manual of Mental Disorders (4th ed - Text Revision 2000) (in effect when defen-
dant committed his crimes and at the time of his trial), as well as the American
Association on Intellectual and Developmental Disabilities’ Intellectual Disability:
Definition, Classification, and Systems of Supports (11th ed 2010).
342	                                                             State v. Agee

paradigm was reflected in the Fourth Edition (text revi-
sion) of the American Psychiatric Association’s Diagnostic
and Statistical Manual of Mental Disorders (4th ed - Text
Revision 2000) (DSM-IV-TR), which defined “mental retar-
dation” as a condition that meets the following three criteria:
    “A.  Significantly subaverage intellectual functioning: an
    IQ of approximately 70 or below on an individually admin-
    istered IQ test * * *.

    “B.  Concurrent deficits or impairments in present adap-
    tive functioning * * * in at least two of the following areas:
    communication, self-care, home living, social/interpersonal
    skills, use of community resources, self-direction, func-
    tional academic skills, work, leisure, health, and safety.

    “C.  The onset is before age 18 years.”

DSM-IV-TR at 49.11 Under the DSM-IV-TR, the severity of
a person’s mental retardation was measured by the person’s
IQ score. A person with an IQ score between about 50-55
and approximately 70 (two standard deviations below nor-
mal) was considered to be mildly mentally retarded and to
have significantly subaverage intellectual functioning.12 Id.
	       The parties introduced evidence that defendant’s
IQ score was measured at 82 or 84 (depending on the test),
which is in the borderline range.13 They also adduced evi-
dence that defendant suffered from some kind of psychosis

	11
        As we will explain, in 2013, the DSM-IV-TR was replaced by the American
Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders
(5th ed 2013).
	12
        A person scoring 100 on an IQ test is considered to have an average level of
cognitive functioning. Atkins, 536 US at 309 n 5. Under the DSM-IV-TR, a person
with an IQ between 35-40 to 50-55 was characterized as moderately mentally
retarded, 20-25 to 35-40 as severely mentally retarded, and under 20-25 as pro-
foundly mentally retarded. DSM-IV-TR at 49.
	13
        Under the DSM-IV-TR, “[b]orderline intellectual functioning * * * describes
an IQ range that is higher than that for Mental Retardation (generally 71-84).”
DSM-IV-TR at 48.
	 Experts administered two IQ tests to defendant: the Wechsler Adult
Intelligence Scale - Fourth Edition (WAIS-IV), and the Stanford-Binet Intelligence
Scales, Fifth Edition (SB5). Both tests have subtests. On the WAIS-IV, defen-
dant’s full-scale IQ score was 82 and his subtest scores ranged from 74 (working
memory) to 102 (perceptual reasoning). On the SB5, defendant’s full-scale IQ
score was 84, and his subtest scores ranged from 78 (non-verbal) to 92 (verbal).
Cite as 358 Or 325 (2015)	343

disorder,14 as well as partial fetal alcohol syndrome,15 among
other things. Defendant’s experts testified that defendant’s
adaptive functioning was equivalent to that of a seven-and-a-
half-year-old and that he had significant functional impair-
ment in each of the 11 areas identified in the DSM-IV-TR for
measuring adaptive functioning. The state’s expert agreed
that defendant’s adaptive functioning score was more than
two standard deviations below the mean—in the range con-
sistent with mild “mental retardation.”
	        Two state experts, Dr. Hulteng and Dr. Sebastian,
testified at the Atkins hearing that the generally accepted
practice in the field of psychology was that a person must
have an IQ score of two standard deviations below the mean
or lower (an IQ score of 70 or lower) to permit a diagnosis
of intellectual disability, irrespective of the person’s adap-
tive behavior. Dr. Hulteng testified that, in his opinion, a
person with an IQ score of over 75 could never qualify as
intellectually disabled. Specifically with respect to this
case, Dr. Hulteng and Dr. Sebastian (who had acted as a
consultant but did not personally examine defendant) testi-
fied that defendant’s IQ scores were too high to establish the
first prong in the diagnosis of mental retardation: “signifi-
cantly subaverage intellectual functioning.”
	       Defendant’s experts testified that an IQ above two
standard deviations below the mean did not exclude an intel-
lectual disability diagnosis. They relied on the American
Association on Intellectual and Developmental Disabilities
(AAIDD) Intellectual Disability: Definition, Classification,
and Systems of Supports (11th ed 2010), which they referred
to as the “Green Book” because of the color of its cover.
According to defendant’s experts, the AAIDD Green Book
	14
        One of defendant’s experts diagnosed defendant with “Psychotic Disorder
(NOS [Not Otherwise Specified]) and/or Amphetamine-Induced Psychotic
Disorder, with Delusions and Hallucinations.” A state expert diagnosed “Psychotic
Disorder (NOS).”
	15
        According to Dr. Adler, a defense expert and medical doctor who conducted
a forensic psychiatric evaluation of defendant, individuals with partial fetal alco-
hol syndrome have a confirmed history of prenatal alcohol exposure and the same
level of damage to the central nervous system and the same functional disabili-
ties as are present with fetal alcohol syndrome, but they do not have all the same
facial deformities that a person with fetal alcohol syndrome would have, and
therefore do not have the same “look” as a person with fetal alcohol syndrome.
344	                                                              State v. Agee

places more emphasis on a person’s adaptive behavior in
an intellectual disability diagnosis.16 One of defendant’s
experts, Dr. Greenspan, testified that IQ tests offer an
incomplete picture of intelligence, because a person with
partial fetal alcohol syndrome, like defendant, cannot apply
his or her IQ to day-to-day activities. Therefore, a broader
definition that measures the way a person functions should
be used to diagnose intellectual disability. Dr. Greenspan
concluded, under both the AAIDD Green Book and DSM-
IV-TR, that defendant met the first prong in the diagnosis
of mental retardation (significantly subaverage intellectual
functioning), because he has significant intellectual deficits,
and that defendant is intellectually disabled.
	        In addition, defense expert Dr. Connor, a neuropsy-
chologist, testified that defendant’s IQ scores were invalid
because of the significant differences among the IQ sub-
scores, such as scores for verbal and nonverbal or perceptual
reasoning. He pointed to an MRI showing that defendant
has brain damage, evidenced by a visible defect in his cor-
pus callosum,17 which likely caused that difference in IQ
subscores. Further, Dr. Connor testified that partial fetal
alcohol syndrome together with defendant’s corpus callosum
damage and his low adaptive functioning supported a diag-
nosis of intellectual disability. For similar reasons, another
defense expert, psychiatrist Dr. Adler, concluded that defen-
dant’s IQ score was not alone determinative of his intellec-
tual functioning. Dr. Adler also ultimately diagnosed defen-
dant as intellectually disabled.
	        At the conclusion of the hearing, the trial court found
that defendant suffered from partial fetal alcohol syndrome.
The court observed that defendant’s experts had opined
that, because of defendant’s partial fetal alcohol syndrome,

	16
         For instance, the AAIDD Green Book provides the following definition of
intellectual disability:
     “Intellectual disability is characterized by significant limitations both in
     intellectual functioning and in adaptive behavior as expressed in conceptual,
     social, and practical adaptive skills. This disability originates before age 18.”
AAIDD Green Book at 5.
	17
        The corpus callosum is a mass of nerve fibers that connects the two sides
of the brain. Dr. Connor testified that the damage to defendant’s corpus callosum
was caused by his mother’s consumption of alcohol during pregnancy.
Cite as 358 Or 325 (2015)	345

defendant’s IQ scores were not as important as their own
clinical judgment and the results of defendant’s neuropsy-
chological tests to their analyses of defendant’s intellectual
functioning. Nonetheless, however, the court concluded that
the consensus in the psychological community, as evidenced
by the DSM-IV-TR and the AAIDD Green Book, was that IQ
is the appropriate measure for diagnosing intellectual dis-
ability. Therefore, because defendant’s IQ was about 84, the
court found that defendant had failed to prove “significantly
subaverage intellectual functioning” under the first prong.
And, because defendant’s IQ scores precluded a finding of
“significantly subaverage intellectual functioning” under
prong one, the court declined to consider prongs two (deficits
or impairments in adaptive functioning) and three (onset in
childhood):
    “Defendant has not proved by a preponderance of the evi-
    dence that he meets the Prong One, ‘significantly sub-average
    intellectual functioning.’ For this reason, the court does not
    reach Prongs Two and Three. One of Dr. Sebastian’s slides
    was a picture of overlapping circles that illustrates the sim-
    ple truth about this case: Atkins does not bar the execu-
    tion of all persons with [fetal alcohol syndrome]. There are
    people with [intellectual disability]. There are people with
    [fetal alcohol syndrome]. There is a small group in the mid-
    dle that has both. Unfortunately, defendant falls outside of
    that group.”

	        Notwithstanding that the trial court expressly
declined to reach the second prong, the court found that,
“[a]s to Prong Two, adaptive functioning, defendant scored
more than two standard deviations below the mean on the
[relevant] tests, averaging minus 2.5.”18 The court added,
however, that, even though it had found that defendant suf-
fered from partial fetal alcohol syndrome, which affected
his adaptive functioning, there was no generally accepted
scientific opinion in the field of psychology that a diagno-
sis of intellectual disability should be made based only on
adaptive functioning. The court concluded that it could not
depart from the three criteria mentioned in Atkins (that
	18
        Additionally, although the trial court did not make a specific finding on the
point, we observe that there appears to have been little dispute that defendant’s
intellectual deficits manifested before age 18.
346	                                                 State v. Agee

is, essentially, the three prongs set out in the DSM-IV-TR)
and the consensus of professional judgment to conclude that
defendant is ineligible for the death penalty.
	        In this court, defendant first repeats the argument
he made below that the trial court should have relied on his
experts’ conclusions that, under the DSM-IV-TR and the
AAIDD Green Book, defendant is intellectually disabled not-
withstanding his relatively high IQ scores, because his par-
tial fetal alcohol syndrome and the resulting deficits in his
adaptive functioning significantly impaired his intellectual
functioning. He contends that the trial court appeared to have
concluded that it was legally bound to side with the state’s
experts, because their interpretation of the DSM-IV-TR and
the AAIDD Green Book—applying a bright-line rule requir-
ing an IQ score of more than two standard deviations below
the mean for a determination of intellectual disability—was
more in line with that of a majority of psychologists and psy-
chiatrists. However, he argues, experts’ opinions should not
be discounted simply because they reflect minority views. In
support of the latter proposition, defendant quotes from this
court’s opinion in State v. Wagner, 305 Or 115, 153-54, 752
P2d 1136 (1988), vac’d and remanded on other grounds by
Wagner v. Oregon, 492 US 914 (1989) (Wagner I):
   “In Bales v. SAIF, 294 Or 224, 656 P2d 300 (1982), we made
   it clear that a decision as to which of two conflicting schools
   of medical thought is correct is not a question of law; it is a
   question of fact to be decided by presenting in proper evi-
   dentiary form the various views to the finder of fact. * * *
   We also observed that the opinion of an expert should not
   necessarily be given less weight by a finder of fact just
   because the witness espouses the view of a minority of his
   profession.”
Defendant argues that, in this case, the so-called “minority”
view was held by one of his witnesses, Dr. Greenspan, whom
the trial court acknowledged to be an expert in intellectual
disability and the author of many studies relied on by the
AAIDD in formulating its definition of intellectual disabil-
ity, as well as by Drs. Adler and Connor. Therefore, he con-
tinues, the trial court had sufficient evidence on which to
base a conclusion that defendant had deficits in intellectual
functioning that rendered him intellectually disabled.
Cite as 358 Or 325 (2015)	347

	        As discussed, at the Atkins hearing, the trial court
found that Atkins, the DSM-IV-TR, and the AAIDD Green
Book all generally required proof of three elements for a
finding of intellectual disability: significantly subaverage
intellectual functioning, significant limitations in adaptive
skills, and onset before the age of 18. The court concluded,
based on Atkins, on its own interpretation of the clinical
manuals, and on the testimony of the state’s experts, that
all three elements, or “prongs,” must be met before the court
could conclude that defendant is intellectually disabled.
	        The trial court stated that the dispute “is not about
whether intellectual disability should be measured accord-
ing to a rigid cutoff or fixed intelligence test score;” rather,
it boiled down to “what weight the court should give to
both the general IQ score and the sub scores in determin-
ing whether this defendant has ‘significantly sub average
intellectual functioning.’ ” In deciding what weight to give
to IQ scores, the court stated that it would rely on the DSM-
IV-TR and the AAIDD Green Book, which, the court found,
both gave significant relevance and weight to IQ scores.
Based on its interpretation of those clinical manuals and
the testimony of the state’s experts, the court concluded
that defendant’s IQ scores and subtest scores were too high
to permit a finding, under the first prong, of “significantly
subaverage intellectual functioning.” In addition, the court
ruled that, even if IQ scores were irrelevant, defendant
could not prove intellectual disability, because his neuro-
psychogical test scores were too high for a finding of sig-
nificantly subaverage intellectual functioning. Finally,
the court concluded that there was no generally accepted
scientific opinion in the field of psychology that diagnosis
of intellectual disability should be based solely on adap-
tive functioning. Principally for those reasons, the court
rejected the opinions of defendant’s experts that defendant
was intellectually disabled.
	       The trial court thus considered and weighed the
evidence presented at the Atkins hearing and, based on
that evidence, ruled that defendant had not met his bur-
den of establishing ineligibility by a preponderance of the
evidence. The trial court did not, as defendant suggests,
use a bright-line rule requiring an IQ score of at least two
348	                                             State v. Agee

standard deviations below the mean for a determination of
intellectual disability in determining whether defendant
had made the necessary showing. The trial court deter-
mined that defendant had not met the first prong—the intel-
lectual functioning prong—based on his IQ scores, but it did
not end its analysis there. Rather, as described, the court
considered defendant’s IQ subtest scores and the results of
other neuropsychological tests administered by the exam-
ining psychologists and psychiatrists and found them all to
be insufficient to establish intellectual disability. For those
reasons, we conclude that the trial court’s Atkins ruling was
not erroneous at the time it was made, and we reject defen-
dant’s argument to the contrary.
	        Alternatively, defendant argues that the publica-
tion of the American Psychiatric Association’s Diagnostic
and Statistical Manual of Mental Disorders (5th ed 2013)
(DSM-5) in May 2013, after the verdict was rendered in this
case, significantly altered the central premise of the trial
court’s legal conclusion, and, therefore, viewed in the light of
present circumstances, the trial court’s ruling was errone-
ous. He asserts that the new DSM-5 diagnostic criteria for
intellectual disability depart from a rigid reliance on IQ test
scores and are in line with the views of his experts, and that
they therefore raise serious questions about the trial court’s
conclusion. He also contends that the Supreme Court’s recent
decision in Hall v. Florida, 572 US __, 134 S Ct 1986, 188
L Ed 2d 1007 (2014), issued during the pendency of this
appeal, supports that view. Defendant therefore urges the
court to remand the case for a new evidentiary hearing in
light of current scientific knowledge, so that the trial court
can make a determination of intellectual disability under
a proper understanding of prevailing medical practice. See
State v. Lawson/James, 352 Or 724, 291 P3d 673 (2012)
(reversing and remanding for a new evidentiary hearing
based on current scientific research and literature in area of
witness identification).
	        The state responds that neither the DSM-5 nor Hall
changed either the definition of intellectual disability or the
legal landscape in a way that materially affects the valid-
ity of the trial court’s determination. The state argues that,
under both the DSM-5 and Hall, intellectual functioning
Cite as 358 Or 325 (2015)	349

is an independent criterion to be met, and IQ is still a key
diagnostic feature in that determination.
	        As we explained above, the DSM-IV-TR required
three diagnostic criteria to be met for a diagnosis of intel-
lectual disability: significantly subaverage intellectual func-
tioning, as evidenced by an IQ of approximately 70 or below;
concurrent deficits in adaptive functioning; and onset before
age 18. DSM-IV-TR at 39-49. The DSM-5 continues to require
three similar criteria, but it deemphasizes reliance on test
scores and emphasizes that the defining quality of intellec-
tual disability is the inability to function in day-to-day life:
   “Intellectual disability (intellectual developmental disorder)
   is a disorder with onset during the developmental period
   that includes both intellectual and adaptive functioning
   deficits in conceptual, social, and practical domains. The
   following three criteria must be met:
   “A.  Deficits in intellectual functions, such as reasoning,
   problem solving, planning, abstract thinking, judgment,
   academic learning, and learning from experience, con-
   firmed by both clinical assessment and individualized,
   standardized intelligence testing.
   “B.  Deficits in adaptive functioning that result in failure
   to meet developmental and socio-cultural standards for
   personal independence and social responsibility. * * *
   “C.  Onset of intellectual and adaptive deficits during the
   developmental period.”
DSM-5 at 33. Where the DSM-IV-TR referred to “signifi-
cantly subaverage intellectual functioning,” the DSM-5 uses
the term “deficits in intellectual functions.” Where the DSM-
IV-TR specifically pointed to “an IQ of approximately 70 or
below on an individually administered IQ test” as establish-
ing “significantly subaverage intellectual functioning,” the
DSM-5 deletes reference to particular IQ scores, emphasiz-
ing instead that clinical assessment and standardized test
results confirm a person’s deficits in intellectual functions.
Similarly, the DSM-IV-TR categorized “mental retardation”
by degree of severity—mild, moderate, or severe—based
solely on IQ scores. DSM-IV-TR at 42. The DSM-5, by con-
trast, provides that severity level is defined by adaptive
functioning, not by IQ score:
350	                                                   State v. Agee

      “The various levels of severity are defined on the basis
      of adaptive functioning, and not IQ scores, because it is
      adaptive functioning that determines the level of supports
      required.”
DSM-5 at 33.
	         Although the DSM-5 recognizes that “[i]ntellectual
functioning is typically measured with individually adminis-
tered and psychometrically valid, comprehensive, culturally
appropriate, psychometrically sound tests of intelligence”
(i.e., IQ tests) and that “[i]ndividuals with intellectual dis-
ability have scores of approximately two standard devia-
tions or more below the population mean,” it nonetheless
states that “[c]linical training and judgment are required to
interpret test results and assess intellectual performance.”
Id. at 37. It notes, further, that
      “IQ test scores are approximations of conceptual function-
      ing but may be insufficient to assess reasoning in real-life
      situations and mastery of practical tasks. For example, a
      person with an IQ score above 70 may have such severe
      adaptive behavior problems in social judgment, social
      understanding, and other areas of adaptive functioning
      that the person’s actual functioning is comparable to that of
      individuals with a lower IQ score. Thus, clinical judgment
      is needed in interpreting the results of IQ tests.”
Id.
	        Those differences reflect a significant change in the
way that intellectual disability is diagnosed, and appear
to permit a finding of “deficits in intellectual functions,”
DSM-5 at 33 paragraph (A), and a diagnosis of intellectual
disability, based in part on significant deficits in adaptive
functioning, as defendant’s experts suggested at the Atkins
hearing. The Supreme Court recognized as much in Hall. As
the Court stated, under the DSM-5, “an individual’s ability
or lack of ability to adapt or adjust to the requirements of
daily life, and the success or lack of success in doing so, is
central to the framework followed by psychiatrists and other
professionals in diagnosing intellectual disability.” 134 S Ct
at 1991; see also 134 S Ct at 2006 (Alito, J., dissenting)
(DSM-5 “fundamentally alters the first prong of the long-
standing, two-pronged definition of intellectual disability
Cite as 358 Or 325 (2015)	351

that was embraced by Atkins and has been adopted by most
States. In this new publication, the [American Psychiatric
Association] discards ‘significantly subaverage intellectual
functioning’ as an element of the intellectual-disability
test.”).
	In Hall, the court considered the constitutionality
of a Florida statute that defined intellectual disability to
require an IQ test score of 70 or less. The defendant in that
case, Hall, had an IQ of 71, which was within the margin of
error for the test, but the Florida Supreme Court held that,
under the state statute, Hall was not entitled to a hearing
to try to establish his intellectual disability and resulting
ineligibility for the death penalty. The Supreme Court held
that, when a defendant has an IQ score between 70 and
75, the defendant’s lawyers must be allowed to offer addi-
tional clinical evidence of intellectual deficit, including the
inability to learn basic skills and adapt to changing circum-
stances. 134 S Ct at 2001. In reaching that conclusion, the
Court observed that the existence of concurrent deficits in
intellectual and adaptive functioning are the defining char-
acteristics of intellectual disability. Id. at 1994. The Court
noted that, on its face, the Florida statute could have been
construed consistently with the way intellectual disability
was discussed in Atkins, which relied on the DSM-IV-TR in
articulating the views of the medical community about how
intellectual disability should be measured and assessed.
Id. However, the Court stated, the Florida Supreme Court’s
interpretation of its statute to bar a person with an IQ score
over 70 from presenting other evidence showing that his or
her faculties were limited created an unacceptable risk that
persons with intellectual disability will be executed, and
was therefore unconstitutional, because it did not permit
the court to consider evidence of deficits in the defendant’s
adaptive functioning. The Court explained:
   	 “Pursuant to this mandatory cutoff, sentencing courts
   cannot consider even substantial and weighty evidence of
   intellectual disability as measured and made manifest by
   the defendant’s failure or inability to adapt to his social
   and cultural environment, including medical histories,
   behavioral records, school tests and reports, and testimony
   regarding past behavior and family circumstances. This is
352	                                                State v. Agee

   so even though the medical community accepts that all this
   evidence can be probative of intellectual disability, includ-
   ing for individuals who have an IQ test score above 70. * * *
   	 “Florida’s rule disregards established medical practice
   in two interrelated ways. It takes an IQ score as final and
   conclusive evidence of a defendant’s intellectual capacity,
   when experts in the field would consider other evidence.
   It also relies on a purportedly scientific measurement of
   defendant’s abilities, his IQ score, while refusing to recog-
   nize that the score is, on its own terms, imprecise.”
Id. at 1994-95.
	         It is true that defendant’s IQ in this case is higher
than that of the defendant in Hall, and, in fact, higher than
the range of scores that the Court was specifically concerned
with in Hall. We also recognize that, unlike the Florida
Supreme Court, the trial court in this case did not use a
strict numerical cutoff when deciding that defendant had
not met his burden of proof. However, the Court’s statements
in Hall about the need to consider a defendant’s serious
deficits in adaptive functioning in determining intellectual
disability for purposes of ineligibility for the death penalty
apply with equal force in the present circumstances. In this
case, the trial court concluded that it would be inappropri-
ate to consider defendant’s deficits in adaptive functioning
in determining whether defendant demonstrated signifi-
cantly subaverage intellectual functioning under the DSM-
IV-TR’s first prong, and it rejected the opinions of defen-
dant’s experts because they considered defendant’s deficits
in adaptive functioning due to partial fetal alcohol syndrome
to diagnose him as intellectually disabled. The trial court
ruled that, because of defendant’s relatively high scores on
IQ and other neuropsychological tests, it would not consider
evidence of defendant’s adaptive functioning deficits. As we
have stated, that ruling was correct when it was made, as
viewed under then-existing published medical standards.
	       Those standards, however, were undergoing change,
as the testimony of defendant’s medical experts suggested,
and the changes are reflected in the DSM-5. Relying on
the new standards, the Court in Hall reversed a Florida
decision because it precluded the trial courts in that state
from considering “even substantial and weighty evidence
Cite as 358 Or 325 (2015)	353

of intellectual disability as measured and made manifest
by the defendant’s failure or inability to adapt to his social
and cultural environment, including medical histories,
behavioral records, school tests and reports, and testimony
regarding past behavior and family circumstances.” Hall,
134 S Ct at 1994. In this case, the trial court also did not
consider that kind of evidence.
	In Atkins and in Hall, the Court observed that indi-
viduals who meet the “clinical definitions” of intellectual
disability bear diminished personal culpability, because, by
definition, they have diminished capacity to understand and
process information, to communicate, to learn from their
mistakes and experiences, to engage in logical reasoning,
to control impulses, and to understand the reactions of oth-
ers. Hall, 134 S Ct at 1993; Atkins, 536 US at 318. As we
have explained, under the DSM-5, the clinical definition of
intellectual disability permits consideration of evidence to
support a finding of a deficit in intellectual functioning that
the trial court in this case believed should be disregarded.
The DSM-5 no longer requires proof of “significantly sub-
average intellectual functioning.” Instead, it simply requires
“deficits” in intellectual functioning, which may be shown in
a variety of ways and confirmed by clinical assessment and
standardized tests. Thus, the consensus of the psychological
community, as reflected in the DSM-5, now recognizes that
intellectual functioning should be interpreted in conjunction
with adaptive functioning in diagnosing intellectual disabil-
ity. DSM-5 at 37 (“The diagnosis of intellectual disability is
based on both clinical assessment and standardized testing
of intellectual and adaptive functioning.”).
	        As we have described, that was essentially the posi-
tion that defendant’s experts took at the Atkins hearing. The
current consensus in the psychological community on this
point is, however, inconsistent with the trial court’s rejec-
tion of defendant’s experts’ diagnosis of intellectual disabil-
ity on the basis that there is no generally accepted scientific
opinion in the field of psychology that adaptive functioning
plays a role in the determination of a deficit in intellectual
function. For that reason, even though the trial court’s rul-
ing comported with the published standards existing at the
time that the court ruled, we now conclude that the trial
354	                                                 State v. Agee

court did not apply now-current medical standards in deter-
mining that defendant had not met his burden of proof to
show that he has an intellectual disability.
	        This court has recognized that a high level of scru-
tiny is required in death penalty cases:
   “Capital cases require our most vigilant and deliberative
   review. We agree with the United States Supreme Court
   statement that ‘[d]eath is a punishment different from all
   other sanctions in kind rather than degree’ so that ‘there is
   a [corresponding] difference in the need for reliability in the
   determination that death is the appropriate punishment in
   a specific case.’ Woodson v. North Carolina, 428 US 280,
   303-05, 96 S Ct 2978, 2991, 49 L Ed 2d 944, 961 (1976).”
State v. Guzek, 322 Or 245, 264, 906 P2d 272 (1995). Allowing
the trial court’s ruling to stand would “create[ ] an unaccept-
able risk that [a] person[ ] with intellectual disability will be
executed.” Hall, 134 S Ct at 1990. We therefore remand for
a new Atkins hearing, in which the trial court shall consider
the evidence presented in light of the standards set out in
the DSM-5 and discussed in Hall.
C.  Defendant’s Penalty-Phase Assignments of Error
	       If, after a new Atkins hearing, the trial court again
determines that defendant is eligible for the death penalty
under Atkins, a second penalty-phase proceeding would not
be required unless this court were to find reversible error
in the penalty-phase proceeding below. Accordingly, we
consider defendant’s penalty-phase assignments of error to
determine whether any is well taken.
    1.  Trial court’s refusal to permit defendant’s experts to
        testify about their diagnoses
	        Defendant contends that the trial court erred
during the penalty phase in refusing to allow his experts
to testify that they had diagnosed defendant as intellec-
tually disabled. Following the trial court’s ruling at the
Atkins hearing that defendant was eligible for the death
penalty, defendant requested the trial court’s permission
to call Drs. Greenspan and Adler to testify that they had
diagnosed defendant as intellectually disabled at a future
penalty-phase hearing, in the event the jury convicted him
Cite as 358 Or 325 (2015)	355

of aggravated murder at the conclusion of the guilt phase.
Defendant explained that the prosecutor and the trial court
had agreed that he could present evidence of intellectual
disability during the penalty phase. Defendant argued that
the jury should consider evidence of intellectual disability
just like other mitigating evidence—something that could,
but need not, merit a life sentence.
	        The trial court stated that it already had deter-
mined that defendant was not intellectually disabled. There-
fore, the court reasoned, the jury must be permitted to con-
sider and give effect to any mitigating evidence, but that
requirement would be met if defendant were able to pres-
ent evidence of his “diminished capacity.” Near the close of
the state’s evidence during the penalty phase, defendant
renewed his request that Drs. Greenspan and Adler be
permitted to testify about their intellectual disability diag-
noses. The court then ruled that “no party could introduce
evidence that defendant was intellectually disabled, includ-
ing evidence from defense experts that they had diagnosed
defendant as intellectually disabled.”
	        In this court, defendant argues that evidence that
two experts diagnosed him as intellectually disabled was rel-
evant to defendant’s character and background and to the cir-
cumstances of the charged offense under ORS 163.150 and the
Eighth Amendment. He argues that all relevant mitigating
evidence is admissible in the penalty phase, and that, under
the Eighth Amendment, evidence that experts diagnosed
him as intellectually disabled is admissible even though the
court had concluded that he was eligible for the death penalty
under Atkins at a pretrial hearing on that issue. Defendant
asserts that legal scholars have recognized that
   “the Atkins decision overruled the aspect of Penry [v.
   Lynaugh, 492 US 302, 109 S Ct 2934, 106 L Ed 2d 256
   (1989)] that had allowed the execution of mentally retarded
   persons. However, the Court’s ruling in Penry that a defen-
   dant must be allowed to present all information to a jury
   that might be considered mitigating evidence, including
   evidence regarding mental capacity and childhood abuse,
   was not altered by the Atkins decision.”
Ronald D. Rotunda and John E. Nowak, 3 Treatise on
Constitutional Law: Substance and Procedure § 17.3(d), 46-47
356	                                                State v. Agee

(5th ed 2012). Indeed, defendant points out, the Supreme
Court has held that
   “a State cannot preclude the sentencer from considering
   any relevant mitigating evidence that the defendant prof-
   fers in support of a sentence less than death. * * * [V]irtu-
   ally no limits are placed on the relevant mitigating evi-
   dence a capital defendant may introduce concerning his
   own circumstances[.]”
Payne v. Tennessee, 501 US 808, 822, 111 S Ct 2597, 115 L Ed
2d 720 (1991) (internal quotation marks and citations omit-
ted). Defendant argues that the trial court violated the
Eighth Amendment when it failed to permit the jury to give
effect to mitigating evidence that he had been diagnosed as
intellectually disabled. Finally, defendant argues that the
error requires reversal because it is likely that the error
affected the verdict and therefore was not harmless.
	        The state responds that the trial court did not
preclude defendant from presenting any substantive evi-
dence of his mental and intellectual deficits, including any
diagnoses of those deficits and the factual bases for them;
it merely ruled that defendant could not elicit testimony
from his experts about their opinion on the ultimate legal
issue—whether defendant was intellectually disabled as
that phrase is used in Atkins for purposes of defining the
scope of the exemption from execution. The state argued
that that ruling was correct, because a witness is not enti-
tled to offer an opinion on a legal issue that is at variance
with the trial court’s ruling. In its briefing before this court,
the state acknowledges, as it must, that “a witness is enti-
tled to offer an opinion within the proper scope of his or
her professional expertise.” Additionally, in oral argument
in this court, the state conceded that, had defendant asked
his experts, during the penalty phase of the trial, to state
their diagnoses of defendant, their testimony to the effect
that they had diagnosed defendant as intellectually disabled
would have been admissible. However, the state argues, that
is not what happened here or what the trial court’s ruling
addressed.
	       Additionally, the state argues that the trial court
did allow defendant to present extensive relevant and
Cite as 358 Or 325 (2015)	357

substantive evidence about his substantial mental and
intellectual deficits, and his experts were permitted to tes-
tify about all their diagnoses, other than their diagnoses
that defendant was intellectually disabled. The state con-
tends that the specific opinion by defendant’s experts that
he is intellectually disabled would not have been relevant to
any issue that was before the jury, because the trial court
had already ruled that he is not intellectually disabled. That
is, the state goes on, it was proper for the jury to hear and
consider evidence regarding the nature, extent, and cause
of defendant’s intellectual deficits, and evidence on those
points was admitted without restriction. But having the
defendant’s experts go one step further to opine that defen-
dant is “intellectually disabled” would not have provided
any additional meaningful information to the jury.
	        As a preliminary matter, after reviewing the record,
we conclude that the state takes an overly narrow view of
the trial court’s ruling. In an Agreed Narrative Statement,
signed by counsel for the state and defendant, the par-
ties memorialized a discussion that they had had with the
trial court in chambers during the penalty phase regard-
ing “limitations on defendant’s evidence.” According to that
statement,
   “defendant informed [the judge] of his intent to offer mit-
   igating evidence that two of his experts, Drs. Adler and
   Greenspan, had diagnosed him as intellectually disabled.
   The evidence would have been identical to the evidence
   defendant offered during the pretrial hearing. [The judge]
   ruled that no party could introduce evidence that defendant
   was intellectually disabled, including evidence from defense
   experts that they had diagnosed defendant as intellectually
   disabled. [The judge] so ruled because she had ruled pre-
   trial that defendant had failed to meet his burden to estab-
   lish that he was ineligible for the death penalty because
   of intellectual disability and she concluded that no party
   could offer evidence inconsistent with that ruling.”
(Emphasis added.) Thus, the agreed narrative confirms that
defendant informed the court of his intention to offer his
experts’ diagnoses of intellectual disability as mitigating
evidence and that the court precluded introduction of those
diagnoses for any and all purposes, and not only to establish
358	                                                            State v. Agee

that defendant was ineligible for the death penalty under
Atkins.19 It is true that the judge cited her earlier Atkins rul-
ing as the reason for excluding the experts’ diagnoses, but
nothing in the Agreed Narrative Statement suggests that
defendant would have been permitted to present evidence of
his experts’ intellectual disability diagnoses as mitigation
evidence.
	        We also disagree with the state that evidence that
two experts diagnosed defendant as intellectually disabled
was irrelevant. The relevance standard set out in OEC 40120
applies in the penalty phase of a capital trial, State v. Stevens,
319 Or 573, 580, 879 P2d 162 (1994), and that standard pro-
vides a “very low threshold for the admission of evidence.”
State v. Gibson, 338 Or 560, 569, 113 P3d 423 (2005). As we
have already discussed, in the fields of psychology and psy-
chiatry, intellectual disability is a valid clinical diagnosis,
and evidence that defendant’s experts made that diagnosis
more than meets that low threshold for admissibility.
	       As defendant points out, the death penalty statutes
plainly provide that a trial court must admit any evidence
relevant to a sentencing jury’s consideration of the sentence
for aggravated murder. ORS 163.150(1)(a) provides that, in
a penalty-phase proceeding,
    “evidence may be presented as to any matter that the court
    deems relevant to sentence including, but not limited to,
	19
        Attached to the Agreed Narrative Statement is an excerpt from the tran-
script in which the court summarized, on the record, the discussion of the court’s
rulings:
    	    “[THE COURT:]  Next, I think we discussed in chambers the parameters
    of the expert testimony here, and we’ve agreed that there would not be testi-
    mony from an expert that went outside the parameters of my findings of fact
    in the Atkins hearing, nor would they—nor would there be cross-examination
    that went beyond those parameters. And I think we agreed that the ‘as if’
    portion of my opinion is basically what these experts will be talking about, if
    that makes sense, and then you’re free to cross-examine about that. Okay?”
The Agreed Narrative Statement acknowledges that that summary is “cryptic”
and it recites that the “agreed narrative statement accurately describes the dis-
cussion and rulings to which the parties referred in the attached pages of the
transcript.”
	20
        OEC 401 provides:
    	 “ ‘Relevant evidence’ means evidence having any tendency to make the
    existence of any fact that is of consequence to the determination of the action
    more probable or less probable than it would be without the evidence.”
Cite as 358 Or 325 (2015)	359

    victim impact evidence relating to the personal character-
    istics of the victim or the impact of the crime on the victim’s
    family and any aggravating or mitigating evidence relevant
    to the issue in paragraph (b)(D) of this subsection[.]”
ORS 163.150(1)(b)(D), referred to in that passage, requires
the court to ask the penalty-phase jury to consider “[w]hether
the defendant should receive a death sentence,” the so-called
“fourth question.”21 As this court stated in Stevens,
    “the legislature intended the scope of the statutory fourth
    question to be co-extensive with the scope of the fourth
    question held in Penry and [State v. Wagner, 309 Or 5, 786
    P2d 93 (1990) (]Wagner II [)] to satisfy the requirements of
    the Eighth Amendment to the Constitution of the United
    States.”
319 Or at 582. As pertinent here, the Supreme Court held
in Penry that a defendant must be allowed to present all
information to a jury that might be considered mitigating
evidence, including evidence regarding mental capacity and
childhood abuse. 492 US at 328. And, in Wagner II, this
court held that all aspects of a defendant’s character and
background are relevant to the jury’s “exercise of a reasoned
moral response to the question ‘should defendant receive a
death sentence?’ ” 309 Or at 19.
	       Dr. Greenspan, a recognized expert in intellec-
tual disability, and Dr. Adler, a forensic psychiatrist, had
diagnosed defendant as intellectually disabled, yet they
were required to omit from their testimony their profes-
sional opinions about that diagnosis—a matter squarely
within their expertise. Their diagnoses were relevant to
	21
       The first three statutory questions, which, like the fourth question, the
jury must unanimously answer affirmatively to impose the death penalty, are:
    	    “(A)  Whether the conduct of the defendant that caused the death of the
    deceased was committed deliberately and with the reasonable expectation
    that death of the deceased or another would result;
    	 “(B) Whether there is a probability that the defendant would commit
    criminal acts of violence that would constitute a continuing threat to society;
    [and]
    	    “(C)  If raised by the evidence, whether the conduct of the defendant in
    killing the deceased was unreasonable in response to the provocation, if any,
    by the deceased[.]”
 ORS 163.150(1)(b)(A), (B), and (C).
360	                                             State v. Agee

defendant’s character and background and to the circum-
stances of the offense under ORS 163.150 and under the
Eighth Amendment, as explained in Penry. 492 US at 328
(intellectual disability is a mitigating fact that a trial court
must permit a jury to consider under Eighth Amendment).
The fact that the state’s experts disagreed with the diag-
nosis does not render it any less relevant. Wagner I, 305 Or
at 153-54 (expert’s opinion should not necessarily be given
less weight just because it reflects minority view). Nor does
the fact that the trial court determined that defendant
had not established his intellectual disability for purposes
of the exemption from the death penalty under Atkins. As
the Supreme Court has stated, “mental retardation for pur-
poses of Atkins, and mental retardation as one mitigator to
be weighed against aggravators, are discrete issues.” Bobby
v. Bies, 556 US 825, 829, 129 S Ct 2145, 173 L Ed 2d 1173
(2009). Evidence that defendant’s experts had diagnosed
him as intellectually disabled was relevant to the fourth
question—whether the defendant should receive a sentence
of death—and defendant was entitled under ORS 163.150
and the Eighth Amendment to present that testimony to the
jury during the penalty phase of his death penalty trial as
mitigating evidence. The trial court erred in excluding it.

	        As we have stated, under state law, this court must
affirm notwithstanding error if there was “little likelihood”
that the error affected the jury’s verdict. Rogers II, 352 Or at
543. And when, as here, the error violates a defendant’s fed-
eral constitutional right, the court may affirm “only when a
‘reviewing court may confidently say, on the whole record,
that the constitutional error was harmless beyond a reason-
able doubt.’ ” State v. Bray, 342 Or 711, 725, 160 P3d 983
(2007) (quoting Delaware v. Van Arsdall, 475 US 673, 681,
106 S Ct 1431, 89 L Ed 2d 674 (1986)). Under either stan-
dard, the trial court’s error in refusing to permit defendant’s
experts to testify about their intellectual disability diag-
noses was not harmless.

	         We have explained that the fourth question is a
“mechanism for the sentencing jury to give meaningful
effect to its consideration of the entire range of possible mit-
igating evidence and to provide a ‘reasoned moral response’
Cite as 358 Or 325 (2015)	361

to the ultimate question of whether the defendant should
live or die.” Wagner II, 309 Or at 13. For that reason, “it
is the rare case in which this court can determine, when
evidence relevant to that question is excluded, that the evi-
dence could not have affected” the jury’s decision whether to
impose the death penalty. Stevens, 319 Or at 585. This is not
that rare case. There is no burden of proof with respect to
the fourth question; a juror may vote not to impose a death
sentence for any reason. ORS 163.150(1)(c)(B).22 Moreover, a
sentence of death must be unanimous. ORS 163.150(1)(e).23
Therefore, even if the fact that two experts had diagnosed
defendant as intellectually disabled would not necessarily
have convinced the jury that the state’s experts were incor-
rect, we cannot say, beyond a reasonable doubt, that it would
not have been sufficient to convince one juror to impose a
sentence less than death.24
	       Because we hold that the trial court erred in refus-
ing to allow defendant’s experts to testify that they had
diagnosed defendant as intellectually disabled and that that
error was not harmless, we vacate defendant’s sentence of
death.
      2.  The trial court’s refusal to instruct the jury that it
          must determine whether defendant is intellectually
          disabled
	        We address two additional issues that are likely
to arise on remand if there is a further penalty phase pro-
ceeding. The first issue, which is related to the one that we
just decided, is whether the trial court erred in refusing to
	22
       ORS 163.150(1)(c)(B) provides:
   	 “The court shall instruct the jury to answer the [fourth question] ‘no’
   if, after considering any aggravating evidence and any mitigating evidence
   concerning any aspect of the defendant’s character or background, or any
   circumstances of the offense and any victim impact evidence as described
   in paragraph (a) of this subsection, one or more of the jurors believe that the
   defendant should not receive a death sentence.”
	23
       ORS 163.150(1)(e) provides:
   	    “The court shall charge the jury that it may not answer any issue ‘yes,’
   under paragraph (b) [setting out the four questions] of this subsection unless
   it agrees unanimously.”
	24
       We do not mean to suggest that the exclusion of relevant evidence could
never be harmless or that the grounds for exclusion of otherwise relevant evi-
dence set out in OEC 403 do not apply.
362	                                                            State v. Agee

instruct the jury that it must determine whether defendant
is intellectually disabled. Following the trial court’s ruling
at the Atkins hearing that defendant was eligible for the
death penalty, defendant requested the trial court, in any
subsequent penalty-phase proceeding, to ask the jury sep-
arately to decide whether it finds that defendant is intel-
lectually disabled and to instruct the jury that an affirma-
tive answer to that question would preclude the possibility
of the death penalty. Defendant argued that, under the
Eighth Amendment, he had a constitutional right to pres-
ent evidence of his intellectual disability, and jurors must be
instructed in a manner that permits them to consider and
give full effect to that evidence. And, defendant contended,
under Atkins, the full effect of evidence of his intellectual
disability is that he is categorically ineligible for the death
penalty. Defendant argued that, if the court did not sepa-
rately instruct the jury about the effect of its finding that
he is intellectually disabled, then jurors could conclude that
he is intellectually disabled but that he still deserved death.
Defendant argued that that result was incompatible with
the law and should not be allowed.
	        The trial court declined to instruct the jury about
intellectual disability, ruling that there is no constitu-
tional or other requirement of a separate jury question on
that issue. In addition to ruling on that question under the
Eighth Amendment, the trial court also concluded that a
separate jury question or instruction on the issue of defen-
dant’s intellectual disability was not required under the
Sixth Amendment.25
	        In this court, defendant argues that both the Sixth
and Eighth Amendments to the United States Constitution
require a separate jury instruction about intellectual dis-
ability. We take the two arguments in turn.
	25
       The Sixth Amendment to the United States Constitution provides:
   	    “In all criminal prosecutions, the accused shall enjoy the right to a speedy
   and public trial, by an impartial jury of the State and district wherein the
   crime shall have been committed, which district shall have been previously
   ascertained by law, and to be informed of the nature and cause of the accu-
   sation; to be confronted with the witnesses against him; to have compulsory
   process for obtaining witnesses in his favor, and to have the Assistance of
   Counsel for his defense.”
Cite as 358 Or 325 (2015)	363

	        Defendant asserts that the Supreme Court has
held that the Sixth Amendment requires that any fact
that increases the punishment for an offense beyond the
statutory maximum, other than the fact of a prior convic-
tion, must be submitted to the jury and proved beyond a
reasonable doubt. Apprendi v. New Jersey, 530 US 466, 490,
120 S Ct 2348, 147 L Ed 2d 435 (2000). In addition, under
the Sixth Amendment, a defendant has the right to have
a jury, rather than a judge, decide on the existence of an
aggravating factor that makes the defendant eligible for the
death penalty. Ring v. Arizona, 536 US 584, 609, 122 S Ct
2428, 153 L Ed 2d 556 (2002). Defendant argues that, if a
defendant is ineligible for the death penalty for any reason,
including age, insanity, or intellectual disability, then he or
she may not be sentenced to death.26 In the particular case
of intellectual disability, defendant argues, under Atkins, a
court may not impose the death penalty on a capital defen-
dant who asserts intellectual disability unless the trier of
fact finds the absence of intellectual disability. If the trier of
fact finds that the defendant is intellectually disabled, then
the statutory maximum is a sentence of life in prison with-
out the possibility of parole. It follows, defendant contends,
that a finding of eligibility for the death penalty is neces-
sary to impose a death sentence, and, therefore, when a
defendant asserts his ineligibility for the death penalty, the
question must be submitted to the jury and proved beyond a
reasonable doubt.

	        The state responds that defendant’s argument takes
the narrow exemption from execution that Atkins announced,
which was based on a mitigating fact (intellectual disabil-
ity), and attempts to convert it into an element that the
state must prove in the negative. That is, the state contends,
defendant has turned the analysis on its head, suggesting,
essentially, that the absence of a mitigating factor is actually
an aggravating factor that the state must prove to the jury

	26
       ORS 137.707(2) (persons under the age of 18 when the crime is committed
are not eligible for the death penalty); Roper v. Simmons, 543 US 551, 574-75,
125 S Ct 1183, 161 L Ed 2d 1 (2005) (Eighth Amendment prohibits executing
minors); Ford v. Wainwright, 477 US 399, 409-10, 106 S Ct 2595, 91 L Ed 2d 335
(1986) (Eighth Amendment prohibits executing the insane); Atkins, 536 US at
321 (Eighth Amendment prohibits executing the intellectually disabled).
364	                                                          State v. Agee

beyond a reasonable doubt. The state argues that nothing in
the Court’s case law suggests that, when the law defines a
mitigating fact that creates an exemption or departure from
the maximum sentence, the state must prove to the jury
that that fact does not exist.
	        We agree with the state that, because intellectual
disability is a fact that operates to reduce rather than to
increase the maximum punishment permitted by a verdict
of guilt, the Sixth Amendment does not require the fact of
intellectual disability to be decided by a jury beyond a rea-
sonable doubt. We likewise conclude that the absence of intel-
lectual disability is not an element of a capital offense for
purposes of the analysis under Ring. Defendant has pointed
to nothing in the opinions in either Apprendi or Ring (or any
other case) to suggest that their holdings apply to a situation
in which a factual finding operates to lower the maximum
allowable punishment rather than to raise the punishment
above the statutory maximum.27 In fact, in Apprendi, the
Court carefully distinguished between “facts in aggravation
of punishment and facts in mitigation,” suggesting just the
opposite:
   “If facts found by a jury support a guilty verdict of mur-
   der, the judge is authorized by that jury verdict to sentence
   the defendant to the maximum sentence provided by the
   murder statute. If the defendant can escape the statutory
   maximum by showing, for example, that he is a war vet-
   eran, then a judge that finds the fact of veteran status is
   neither exposing the defendant to a deprivation of liberty
   greater than that authorized by the verdict according to
   statute, nor is the judge imposing upon the defendant a
   greater stigma than that accompanying the jury verdict
   alone. Core concerns animating the jury and burden-of-
   proof requirements are thus absent from such a scheme.”
Apprendi, 530 US at 491 n 16 (citation omitted). Like the
finding of veteran status that the Court used in its example,
a finding of intellectual disability permits the defendant to
“escape the statutory maximum.” That is, a defendant’s intel-
lectual disability reduces the maximum possible sentence
	27
        Moreover, as defendant concedes, no court that has considered the issue
has concluded that the Sixth Amendment requires a claim of intellectual disabil-
ity under Atkins to be resolved by the jury.
Cite as 358 Or 325 (2015)	365

from capital punishment to life in prison. Therefore, the
absence of intellectual disability is not an element that the
state must prove beyond a reasonable doubt.
	        Defendant also argues that, under the Eighth Amend-
ment, the fact of intellectual disability is conclusively miti-
gating. That is, he asserts, if a trier of fact finds that a cap-
ital defendant is intellectually disabled, then the Eighth
Amendment prohibits execution. At the same time, however,
as the Court observed in Atkins and in Penry, evidence of a
defendant’s intellectual disability “can be a two-edged sword
that may enhance the likelihood that the aggravating factor
of future dangerousness will be found by the jury.” Atkins,
536 US at 321; Penry, 492 US at 324. For that reason, defen-
dant asserts, the Court in Penry suggested that the jury
must be instructed in a way that ensures that the jury will be
permitted to fully consider the mitigating effect of evidence
of a capital defendant’s intellectual disability. In defendant’s
view, that means that the jury must be instructed that it
must decide whether a defendant is intellectually disabled
and that, if it so finds, defendant is ineligible for the death
penalty.
	         Defendant’s argument is based on a faulty premise:
that, if the jury were to find, as a factual matter, that he is
intellectually disabled, then the Eighth Amendment prohib-
its his execution. Whether the Eighth Amendment prohib-
its a defendant’s execution is a legal determination, and not
a factual one. As the Supreme Court stated in Hall, “[t]he
legal determination of intellectual disability is distinct from
a medical diagnosis,” even if it is informed by the medical
community’s diagnostic framework. 134 S Ct at 2000. And
while Atkins and Hall require that that legal determination
be made before an arguably intellectually disabled defendant
may be executed, the Court in Atkins specifically left it to the
states to “develop[ ] appropriate ways to enforce the consti-
tutional restriction upon [their] execution of sentences.” 536
US at 317. Nothing in Atkins, or in Hall or Penry, suggests
that the Eighth Amendment or any other constitutional pro-
vision dictates a particular process, or specifically requires
the jury, or even the trial court for that matter, to determine,
as a matter of law, a defendant’s eligibility for the death pen-
alty. In this case, using a process that defendant acceded
366	                                                             State v. Agee

to—the pretrial Atkins hearing—the trial court made that
legal determination. And, having made that determination,
the trial court did not err in refusing to require the jury to
decide the matter a second time.28
	        That is not to say that jurors may not make their
own determinations as a factual, medical matter, based on
the evidence presented, whether defendant is intellectually
disabled. As we have previously noted, the Supreme Court
pointed out in Bies that “[intellectual disability] for pur-
poses of Atkins, and [intellectual disability] as one mitiga-
tor to be weighed against aggravators, are discrete issues.”
556 US at 829. We have already held that defendant was
entitled, under ORS 163.150 and the Eighth Amendment,
to present evidence of his experts’ intellectual disability
diagnoses to the jury during the penalty phase of his death
penalty trial as mitigating evidence, because that evidence
was relevant to the fourth question, whether the defendant
should receive a sentence of death. However, because the
Eighth Amendment does not require the jury to decide the
legal question whether defendant is ineligible for the death
penalty because of his intellectual disability,29 it follows
that the trial court did not err in refusing to instruct the
jury that it must find whether defendant is intellectually
disabled.

	28
        We do not mean to suggest that it would be error for a trial court to permit
the jury to decide the legal question of intellectual disability. That issue is not
before us. Rather, we hold here that neither the Sixth nor Eighth Amendment to
the United States Constitution requires the jury to make such a determination.
	29
        To the extent that defendant’s reference to Penry, and its statement to the
effect that intellectual disability evidence can be a two-edged sword, reflects a
further argument that the jury should have been instructed in such a way as
to ensure that that the jury will treat evidence of intellectual disability as miti-
gating rather than aggravating, that argument is not preserved. Defendant pre-
sented the trial court with two proposed jury instructions concerning mitigation
during the penalty phase of his trial: Defendant’s Special Jury Instruction No. 1—
Definition of Mitigating Evidence, and Defendant’s Special Jury Instruction
No. 2—Consideration of Evidence in Mitigation. Neither instruction would have
informed the jury that it should consider evidence of intellectual disability as
mitigating only. Defendant requested that the trial court pose a question to the
jury about intellectual disability, but his arguments in court and in his memo-
randum on that point were confined to ensuring that the jury be instructed that
a finding of intellectual disability has a “conclusive mitigating effect,” by which
defendant specifically meant that, “[i]f the jury finds that a defendant is intellec-
tually disabled, notwithstanding a trial court’s previous determination, then the
defendant is not eligible for the death penalty.”
Cite as 358 Or 325 (2015)	367

    3.  The trial court’s exclusion of evidence that Davenport
        received a life sentence
	         The last issue that we address is whether the trial
court erred in granting the state’s motion in limine to exclude
evidence during the penalty phase that Davenport received
a life sentence for his role in the victim’s murder.
	        In its motion, the state argued that neither Davenport’s
sentence nor evidence related to his intellectual disability was
relevant to any fact at issue in the case. Defendant responded
that evidence that an equally or more culpable codefendant
received a life sentence was a circumstance of the offense and,
therefore, proper mitigation evidence under ORS 163.150 and
the Eighth Amendment. The trial court granted the state’s
motion to exclude evidence, testimony, or argument about
Davenport’s sentence, deciding that it would not admit the
evidence under ORS 163.150 and concluding that the Eighth
Amendment did not require its admission.
	        In this court, defendant reprises the arguments
he made below, arguing that both ORS 163.150 and the
Eighth Amendment require admission of Davenport’s sen-
tence during the penalty phase. We begin our analysis by
first considering the matter under the state statute. State v.
Sarich, 352 Or 601, 617, 291 P3d 647 (2012) (court considers
questions of state law before questions of federal law and
issues of statutory interpretation before issues of constitu-
tional interpretation). If the statutory source of law provides
a complete answer to the legal question presented, we ordi-
narily decide the case on that basis, rather than turning to
constitutional provisions. Rico-Villalobos v. Guisto, 339 Or
197, 205, 118 P3d 246 (2005).
	       As we have stated, during the penalty phase, “evi-
dence may be presented as to any matter that the court
deems relevant to sentence including * * * any * * * mitigating
evidence relevant to” the fourth question, whether the defen-
dant should receive a sentence of death. ORS 163.150(1)(a).
Although that paragraph permits introduction of any mit-
igating evidence relevant to the fourth question, ORS
163.150(1)(c)(B) provides that the trial court must instruct
the jury to answer “no” to the fourth question “if, after
considering any aggravating evidence and any mitigating
368	                                            State v. Agee

evidence concerning any aspect of the defendant’s character
or background, or any circumstances of the offense * * *, one
or more of the jurors believe that the defendant should not
receive a death sentence.” Thus, the universe of “any miti-
gating evidence” relevant to the fourth question under ORS
163.150(1)(a) is circumscribed by ORS 163.150(1)(c)(B). To
be relevant to the fourth question, “evidence must relate
to some aspect of the defendant’s character or background
or to any circumstance of the crime.” State v. Barone, 328
Or 68, 97, 969 P2d 1013 (1998) (neither victim’s personal
opposition to death penalty nor expert’s opinion that death
penalty does not deter violent crime was admissible during
defendant’s penalty phase hearing because neither was rel-
evant to defendant’s character or background or to any cir-
cumstance of crime); State v. Longo, 341 Or 580, 606-09, 148
P3d 892 (2006) (trial court did not err in excluding evidence
relating to defendant’s capture and return from Mexico,
because it was not relevant to defendant’s character and did
not make it less likely that he planned the murders).

	        Evidence is “relevant” under ORS 163.150 if it is
relevant under OEC 401. Stevens, 319 Or at 580 (“The stan-
dard of relevance set forth in OEC 401 applies in penalty-
phase proceedings.”); see also McKoy v. North Carolina, 494
US 433, 440, 110 S Ct 1227, 108 L Ed 2d 369 (1990) (mean-
ing of relevance no different in context of mitigating evi-
dence introduced in capital sentencing proceeding than in
any other context). As the Supreme Court stated in McKoy,
in the context of capital sentencing proceedings, “[r]elevant
mitigating evidence is evidence which tends logically to
prove or disprove some fact or circumstance which a fact-
finder could reasonably deem to have mitigating value.” 494
US at 440. As in noncapital cases, the threshold for rele-
vance in death penalty cases is very low. Stevens, 319 Or
at 584; State v. Davis, 351 Or 35, 48, 261 P3d 1197 (2011)
(relevance standard for admissibility is a low bar).

	       Moreover, in the death penalty context, whether
evidence is “mitigating” also is a low standard. Notably, evi-
dence need not necessarily relate to the defendant’s guilt for
the crime to be mitigating. Stevens, 319 Or at 583; Tennard
v. Dretke, 542 US 274, 285-86, 124 S Ct 2562, 159 L Ed 2d
Cite as 358 Or 325 (2015)	369

384 (2004). Rather, as the Supreme Court stated in Tennard,
the question is whether the evidence “would be ‘mitigating’
in the sense that it might serve as a basis for a sentence less
than death.” 542 US at 285 (citations and internal quotation
marks omitted). That is, evidence is mitigating “if the sen-
tencer could reasonably find that it warrants a sentence less
than death.” McKoy, 494 US at 441.
	        Stevens illustrates the low threshold for both rele-
vance and mitigation. In that case, the defendant asserted
that the trial court had erred in sustaining the state’s objec-
tion to a question that his lawyer had asked a state’s wit-
ness on cross-examination, arguing that that evidence was
relevant to the fourth question. The witness (the defendant’s
estranged wife) had been asked to give her opinion about the
potential negative effect of the defendant’s execution on their
daughter. 319 Or at 584. This court acknowledged that that
testimony would not offer any direct evidence about defen-
dant’s character or background, but concluded that, circum-
stantially, it could permit a rational juror to infer that there
were positive aspects to the defendant’s character that could
justify a sentence less than death. Id. For that reason, the
court held that the testimony was sufficiently related to the
defendant’s character as to be relevant in mitigation.
	        The question in this case is whether evidence of
Davenport’s life sentence is similarly relevant in mitigation
to the jury’s consideration of the fourth question. The state
argues that a sentence imposed on a codefendant does not
have a tendency to show any aspect of a defendant’s char-
acter or background, nor does it tend to show any relevant
circumstance of the offense. The state contends that a defen-
dant facing the death penalty is entitled to an individual-
ized consideration of whether death is appropriate, which
should be based on the defendant’s own personal circum-
stances, his entire personal and criminal history, and his
personal culpability for the crime. According to the state,
disclosing to the jury that a codefendant received a sen-
tence other than death would be confusing and irrelevant,
because the codefendant’s sentence would have been based
on factual and legal circumstances that were unique to that
person. As such, they would have no logical relevance to the
appropriate punishment for the defendant.
370	                                            State v. Agee

	        The state characterizes defendant’s argument as
positing that, if the jurors in this case found that Davenport
was the person primarily responsible for the murder and
that defendant himself was only an accomplice, then the
jury could conclude, based on the fact that Davenport was
sentenced to life in prison, that the death penalty was not
an appropriate sentence for him. But, the state responds, the
law in Oregon is well established that one who intentionally
aids another in the commission of a crime is just as guilty
as the person who committed the crime. ORS 161.155(2) (so
providing). The state asserts that the personal culpability
of the accomplice does not depend at all on whether, or the
degree to which, the principal offender also was convicted
and punished, and nothing in Oregon law suggests that a
person convicted of a crime as an accomplice is entitled to a
more lenient sentence than, or even the same sentence as,
that imposed on the principal.
	        Although it is a close question, we conclude that
evidence that Davenport received a life sentence is relevant
mitigating evidence under ORS 163.150. First, we conclude
that Davenport’s sentence is relevant to “[an] aspect of the
defendant’s character or background, or [a] circumstance of
the offense” under ORS 163.150(1)(c)(B). The circumstances
of the offense include the facts, established during the guilt
phase of the trial, that defendant and Davenport jointly
participated in the victim’s murder and that Davenport
was primarily responsible for the victim’s death. Davenport
volunteered to kill the victim for his gang, he planned the
crime, he talked defendant into helping him, and he wielded
the instrument that physically caused the victim’s death.
Davenport’s sentence for his participation in the murder,
including the reason that he received that sentence—that
he was found to be intellectually disabled—are related to
those circumstances, because, to the extent that the jury
believed that defendant acted under Davenport’s influence,
they reflect, at least circumstantially, on defendant’s own
intellectual capacities.
	        Second, evidence of Davenport’s life sentence is
mitigating, in the sense that a juror could reasonably find
that it warrants a sentence less than death. As we have
stated, the question for the jury during the penalty phase,
Cite as 358 Or 325 (2015)	371

ultimately, is “whether the defendant should live or die,” and
the fourth question is a mechanism for the jury “to provide a
‘reasoned moral response’ ” to that question. Wagner II, 309
Or at 13. As we have just noted, Davenport was primarily
responsible for the victim’s death and, defendant argued,
talked defendant into participating in the killing. The fact
that Davenport did not receive a death sentence because the
court determined that he was intellectually disabled reflects
indirectly on defendant’s own potential intellectual disabil-
ity and, for the reasons the Court stated in Penry, on his
moral culpability. That possibly mitigating circumstance
is appropriately part of the jury’s consideration of whether
defendant deserves death.

	        Because the fact that Davenport received a life sen-
tence for his role in the victim’s murder was relevant miti-
gating evidence under ORS 163.150, the trial court erred in
excluding it.30 On remand, if a new penalty-phase proceeding
	30
        State v. Casey, 108 Or 386, 213 P 771, motion to recall mandate den, 108
Or 418, 217 P 632 (1923), cited by the state, is not to the contrary. In Casey, the
defendant and a codefendant were jointly charged with murder but were tried
separately. The defendant was tried first, convicted, and sentenced to death;
subsequently, the codefendant was acquitted. The defendant raised various chal-
lenges based on the fact of the codefendant’s acquittal, but, ultimately, this court
held that the codefendant’s acquittal was not relevant and did not “in any way
affect or mitigate the penalty in the case at bar.” Id. at 423. Casey is not helpful
to the state. It did not involve a sentence received by an equally or more culpable
codefendant. Rather, the codefendant there expressly was found not to be guilty
of the crime at all. It therefore sheds no light on the admissibility in a defendant’s
penalty phase proceeding of evidence that an equally or more culpable codefen-
dant received a sentence less than death.
	 Additionally, we reject the state’s argument that permitting the jury to
consider, as mitigation, evidence that an equally or more culpable codefendant
received a sentence less than death would be inherently confusing to the jury.
Such evidence routinely has been admitted and argued in mitigation in capital
cases around the country for decades. In fact, a federal statute and at least one
state statute require factfinders in capital murder cases to consider, as a miti-
gating factor, whether “[a]nother defendant or defendants, equally culpable in
the crime, will not be punished by death.” 18 USC § 3592(a)(4); New Hampshire
Criminal Code § 630:5 (VI)(g) (requiring jurors to consider, in determining
whether to impose death penalty, whether “another defendant or defendants,
equally culpable in the crime, will not be punished by death”). And, although
many states do not permit or require evidence of a codefendant’s sentence less
than death to be considered by the jury, courts in several states either permit
consideration of a codefendant’s sentence in mitigation or have at least suggested
that such evidence is relevant and admissible. E.g., Brookings v. State, 495 So 2d
135, 142-43 (Fla 1986) (jurors in capital case may be permitted to consider code-
fendants’ sentences as mitigating factor); State v. Marlow, 163 Ariz 65, 72, 786
372	                                                           State v. Agee

is required, evidence of Davenport’s sentence, including the
reason for it, should be admitted as mitigating evidence if
introduced.31
                    III. CONCLUSION
	        To summarize, defendant raises 29 assignments of
error. We discuss five of those assignments of error in this
opinion, and we hold that three are well taken. Specifically,
we hold, first, that, although the trial court erred in permit-
ting the prosecutor effectively to depose defendant’s codefen-
dant, Davenport, at a pretrial hearing, that error was harm-
less. Second, we hold that, at defendant’s Atkins hearing,
the trial court used an inappropriate standard in determin-
ing that defendant had not met his burden of proving his
intellectual disability, and we therefore remand for a new
Atkins hearing, in which the trial court shall consider the
evidence presented in light of the standards set out in the
DSM-5 and discussed in Hall. Third, we hold that, during
the penalty-phase proceeding below, the trial court erred in
refusing to permit defendant’s experts to testify that they
had diagnosed defendant as having an intellectual disabil-
ity and that that error was not harmless. Therefore, if the
trial court again rules at the conclusion of the Atkins hear-
ing that defendant does not have an intellectual disability,
a new penalty-phase proceeding will be required. Fourth,
we hold that neither the Sixth nor the Eighth Amendment
to the United States Constitution requires the trial court to
instruct the jury that it must determine whether a defendant
has an intellectual disability. Fifth and finally, we hold that
the trial court erred during the penalty-phase proceeding in
excluding evidence that Davenport received a life sentence
for his role in the victim’s murder, and that, if introduced at
a penalty-phase proceeding on remand, that evidence must
be admitted.

P2d 395, 402 (1989) (fact that codefendant received lesser sentence, no matter the
reason, must be considered by jury and may be found as mitigating circumstance
and weighed against any aggravating circumstances, in determining whether to
impose the death penalty on defendant); Howell v. State, 860 So 2d 704, 762 (Miss
2003) (trial court properly instructed jurors to consider sentence of codefendant
as mitigating evidence); Garden v. State, 844 A2d 311, 317 (Del 2004) (recogniz-
ing codefendant’s life sentence as a mitigating factor).
	31
        Because we resolve the issue on statutory grounds, we do not reach defen-
dant’s constitutional arguments.
Cite as 358 Or 325 (2015)	373

	        The judgment of conviction is affirmed. The sen-
tence of death is vacated, and the case is remanded to the
circuit court for further proceedings.
