State v. Agee ( 2015 )


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  • 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 23, 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
    permit either party to conduct pretrial examination of wit-
    nesses except in certain limited circumstances. For exam-
    ple, 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 ORS 135.873 (set-
    ting out rules for pretrial discovery in criminal prosecu-
    tions). 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 cer-
    tain 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 crimi-
    nal 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 permit-
    ting the prosecutor 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
    Cite as 
    358 Or 325
     (2015)	335
    all of a witness’s testimony if the witness refused to answer
    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
    336	                                            State v. Agee
    and likely affected the verdict, because the prosecution was
    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
    Cite as 
    358 Or 325
     (2015)	337
    to murder the victim and that defendant had done nothing
    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,
    338	                                                         State v. Agee
    that he had been the cellmate of two other gang members,
    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 sentence
    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
    him to death when he had established functional deficits equivalent to, and in
    many instances worse than, other individuals who have been deemed intellec-
    tually 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 classi-
    fied 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 argument 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 penalty 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
    procedure for making that determination. Rather, the Court
    left it to the states to develop “appropriate ways to enforce
    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
    in this case invited suggestions from the parties about how
    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.
    Cite as 
    358 Or 325
     (2015)	341
    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 prevail-
    ing standards for making the determination of intellectual
    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
    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 per-
    sons from execution would apply equally to all individuals with intellectual defi-
    cits similar in severity to those required for a diagnosis of intellectual disability,
    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 diag-
    nosis 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
    (3) whether the disability manifested before adulthood. That
    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’s) 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-aver-
    age 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 simple truth about this case: Atkins does not bar the
    execution 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 middle 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 dis-
    order) is a disorder with onset during the developmental
    period that includes both intellectual and adaptive func-
    tioning 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 abil-
    ity 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 subav-
    erage 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
    ,
    303-305, 
    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.
    Therefore, the court reasoned, the jury must be permit-
    ted to consider and give effect to any mitigating evidence,
    but that requirement would be met if defendant were able
    to present evidence of his “diminished capacity.” Near the
    close of the state’s evidence during the penalty phase, defen-
    dant 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),
    356	                                                State v. Agee
    46-47 (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 mqay 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
    omitted). 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 intellectual
    disability, and Dr. Adler, a forensic psychiatrist, had diag-
    nosed defendant as intellectually disabled, yet they were
    required to omit from their testimony their professional
    opinions about that diagnosis—a matter squarely within
    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
    their expertise. Their diagnoses were relevant to defen-
    dant’s character and background and to the circumstances
    of the offense under ORS 163.150 and under the Eighth
    Amendment, as explained in Penry. 
    492 US at 328
     (intel-
    lectual 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 diagnosis
    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 diagno-
    ses 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 (intellec-
    tual disability), 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, sug-
    gesting, essentially, that the absence of a mitigating factor
    is actually an aggravating factor that the state must prove
    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
    to the jury 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 depar-
    ture 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
    Amendment, the fact of intellectual disability is conclusively
    mitigating. That is, he asserts, if a trier of fact finds that a
    capital 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 * * * miti-
    gating evidence relevant to” the fourth question, whether
    the defendant should receive a sentence of death. ORS
    163.150(1)(a). Although that paragraph permits intro-
    duction of any mitigating 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
    368	                                             State v. Agee
    and any mitigating 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 mitigating 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, “evi-
    dence must relate to some aspect of the defendant’s char-
    acter 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 hear-
    ing because neither was relevant to defendant’s character
    or background or to any circumstance 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 rel-
    evant 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.