Breton v. Commissioner of Correction ( 2017 )


Menu:
  • ******************************************************
    The ‘‘officially released’’ date that appears near the
    beginning of each opinion is the date the opinion will
    be published in the Connecticut Law Journal or the
    date it was released as a slip opinion. The operative
    date for the beginning of all time periods for filing
    postopinion motions and petitions for certification is
    the ‘‘officially released’’ date appearing in the opinion.
    In no event will any such motions be accepted before
    the ‘‘officially released’’ date.
    All opinions are subject to modification and technical
    correction prior to official publication in the Connecti-
    cut Reports and Connecticut Appellate Reports. In the
    event of discrepancies between the electronic version
    of an opinion and the print version appearing in the
    Connecticut Law Journal and subsequently in the Con-
    necticut Reports or Connecticut Appellate Reports, the
    latest print version is to be considered authoritative.
    The syllabus and procedural history accompanying
    the opinion as it appears on the Commission on Official
    Legal Publications Electronic Bulletin Board Service
    and in the Connecticut Law Journal and bound volumes
    of official reports are copyrighted by the Secretary of
    the State, State of Connecticut, and may not be repro-
    duced and distributed without the express written per-
    mission of the Commission on Official Legal
    Publications, Judicial Branch, State of Connecticut.
    ******************************************************
    ROBERT BRETON v. COMMISSIONER
    OF CORRECTION
    (SC 19072)
    Rogers, C. J., and Palmer, Eveleigh, McDonald and Robinson, Js.*
    Argued October 21, 2016—officially released May 23, 2017
    Victoria L. Steinberg, pro hac vice, with whom were
    Moira L. Buckley and, on the brief, William H. Ket-
    tlewell, pro hac vice, and Jason A. Casey, pro hac vice,
    for the appellant (petitioner).
    Harry Weller, senior assistant state’s attorney, with
    whom were Cynthia S. Serafini, senior assistant state’s
    attorney, and, on the brief, Maureen Platt, state’s attor-
    ney, and Michael Proto and Marcia Pillsbury, assistant
    state’s attorneys, for the appellee (respondent).
    Opinion
    McDONALD, J. The petitioner, Robert Breton, was
    found guilty of two counts of murder and one count of
    capital felony for the 1987 stabbing deaths of his former
    wife and his son, and was sentenced to death.1 The
    petitioner thereafter filed a petition for a writ of habeas
    corpus, attacking both his conviction and his death
    sentence. This appeal ensued after the habeas court
    denied the petition. Subsequent events have rendered
    the petitioner’s claims relating to his death sentence
    moot; see part II of this opinion; leaving for our consid-
    eration those challenging the judgment of conviction.
    The principal issue in those remaining claims con-
    cerns defense counsel’s obligation to investigate and
    present mitigating evidence that could reduce a defen-
    dant’s culpability when the defendant has directed
    counsel not to present such evidence and has refused to
    aid in the presentation of such evidence. The petitioner
    claims, among other things, that his criminal trial coun-
    sel provided deficient representation by failing to inves-
    tigate evidence that would have revealed that he
    suffered from post-traumatic stress disorder (PTSD)
    and methamphetamine intoxication at the time of the
    offenses, which in turn prejudiced him by depriving
    him of a meritorious mitigating defense strategy. Specif-
    ically, the petitioner points to counsel’s failure to: (1)
    discover transcripts memorializing the petitioner’s
    account of fatally stabbing his father in 1966; and (2)
    test the petitioner’s blood sample drawn approximately
    forty hours after the crimes. The petitioner contends
    that, contrary to the habeas court’s conclusions, his
    refusal to admit to the 1987 crimes and his instruction
    to counsel not to present an extreme emotional distur-
    bance defense does not preclude relief because counsel
    had not adequately advised him of the evidence that
    was available due to their deficient investigation and
    they should not have acquiesced to the petitioner’s unin-
    formed decision.
    We conclude that counsel must ensure that a defen-
    dant has made a knowing and voluntary decision not
    to present mitigating evidence. We further conclude
    that the habeas court properly denied the petition in
    the present case as to the claims related to this issue,
    as well as to the petitioner’s other claims challenging
    his conviction.
    I
    CRIMINAL TRIAL
    The underlying criminal proceedings were the subject
    of three previous appeals to this court. See State v.
    Breton, 
    212 Conn. 258
    , 259, 
    562 A.2d 1060
    (1989) (Breton
    I) (reversing trial court’s decision dismissing aggravat-
    ing factor of capital felony and remanding case with
    direction to proceed with penalty phase); State v.
    Breton, 
    235 Conn. 206
    , 260, 
    663 A.2d 1026
    (1995) (Breton
    II) (affirming judgment of conviction but reversing judg-
    ment imposing death sentence—first penalty phase—
    and remanding for new penalty phase hearing); State
    v. Breton, 
    264 Conn. 327
    , 446, 
    824 A.2d 778
    (Breton III)
    (affirming judgment imposing death sentence in second
    penalty phase), cert. denied, 
    540 U.S. 1055
    , 
    124 S. Ct. 819
    , 
    157 L. Ed. 2d 708
    (2003). In Breton 
    II, supra
    , 212–14,
    this court set forth the facts that the jury reasonably
    could have found at the guilt phase of the proceedings
    in support of the conviction. We briefly summarize the
    most salient of those facts, and supplement them with
    undisputed facts in the record regarding the circum-
    stances leading to the present appeal.
    Sometime before 4:30 a.m. on Sunday, December 13,
    1987, the petitioner entered the town house apartment
    where his former wife, JoAnn Breton, and their fifteen
    year old son, Robert Breton, Jr., had resided since the
    couple’s divorce in January, 1987. The petitioner was
    armed with a knife. He proceeded to JoAnn Breton’s
    bedroom, where he viciously beat and stabbed her.
    Robert, Jr., came to the bedroom in response to his
    mother’s cries, but fled when the petitioner turned the
    attack on him. The petitioner pursued Robert, Jr., to
    the bottom of the staircase on the first floor, where the
    attack resumed. Both Robert, Jr., and JoAnn Breton
    sustained multiple knife wounds to the face, chest and
    neck. Each bled to death from a knife wound severing
    the carotid artery.
    The petitioner left the apartment and, at some point
    thereafter, drove to a nearby reservoir. Later Sunday
    morning, he called someone to pick him up at the reser-
    voir because his truck had gotten stuck. Sunday eve-
    ning, he went to work. He made arrangements with
    Domenic Aurigemma, a friend and coworker, to retrieve
    the truck the next day. When the men met on Monday
    morning, December 14, the petitioner asked Aurigemma
    to first drive him over to JoAnn Breton’s apartment
    because he had repeatedly gotten a busy signal when
    he telephoned her over the weekend. Upon their arrival,
    the petitioner went to the apartment door but then
    returned to alert Aurigemma that he thought that there
    was blood on the doorknob. They then called the police.
    After the police arrived, obtained entry to the apart-
    ment, and discovered the bodies, they interviewed the
    petitioner. They noticed that the petitioner’s hand was
    bandaged, with blood around the wound. An investiga-
    tion that same day yielded evidence inculpating the
    petitioner. One witness reported hearing screams and
    then seeing the petitioner leave the apartment at
    approximately 4:30 a.m. on December 13. That same
    witness also reported having been told by Robert, Jr.,
    that the petitioner had threatened to kill JoAnn Breton.
    The petitioner was arrested at approximately 8 p.m. on
    Monday, December 14, 1987. A search warrant executed
    at the petitioner’s apartment yielded a pair of recently
    washed sneakers, still wet, that matched bloody foot-
    prints in the apartment. At approximately 9 p.m. on
    December 14, the police executed a search warrant that
    compelled the petitioner to submit to the drawing of a
    blood sample. The state never tested that blood sample
    to match it to blood at the scene. Instead, a second
    sample was drawn and tested by the state in March,
    1989, by agreement of the parties, after defense counsel
    moved to suppress the first sample on the ground that
    the warrant affidavit contained false statements attrib-
    uted to the petitioner.
    Approximately one month before jury selection was
    to commence, defense counsel requested that the court
    order a competency evaluation of the petitioner due to
    concerns arising from their conversations with him.
    The trial court, Heiman, J., ordered an independent
    evaluation by a team of clinicians, who later reported to
    the court that the petitioner understood the proceedings
    against him and was able to assist in his defense.
    While jury selection was in progress, defense counsel
    raised further concerns to the court when responding
    to the deadline for giving notice as to whether they
    would be presenting any expert testimony during the
    guilt phase in support of defenses relating to the peti-
    tioner’s mental state. See Practice Book § 40-18. Coun-
    sel informed the court that they believed that there was
    important evidence related to the petitioner’s mental
    state that could provide the jury with a basis to convict
    the petitioner of the lesser offense of manslaughter.
    Nevertheless, the petitioner had told counsel that he
    did not want them to present a defense of extreme
    emotional disturbance.2 Counsel explained that they
    believed that they must acquiesce to the petitioner’s
    wishes but asked the court to confirm the petitioner’s
    position. The trial court then engaged in a colloquy
    with the petitioner to confirm that he understood that
    evidence of extreme emotional disturbance could
    reduce his culpability from murder to manslaughter,
    but that he had nonetheless instructed his counsel not
    to file ‘‘any notices of claims of extreme emotional
    disturbance’’ and, additionally, that he had instructed
    them not to produce ‘‘any psychiatric evidence’’ at the
    guilt phase of trial. After receiving that confirmation,
    the court found the petitioner competent to make this
    decision. The court informed the petitioner that such
    a defense still might be presented if he later changed
    his mind. The court also informed the petitioner that
    his wishes did not foreclose the possibility that the
    court could charge the jury on extreme emotional dis-
    turbance if the evidence warranted such an instruction.
    The state’s attorney confirmed on the record his under-
    standing that defense counsel had not precluded the
    presentation of expert testimony relating to the petition-
    er’s mental condition at the penalty phase.
    During the guilt phase of trial, the defense solely
    advanced a theory of reasonable doubt. Counsel cross-
    examined the state’s witnesses in an effort to call into
    question the credibility of the eyewitness identification
    and the physical evidence linking the petitioner to the
    crime scene. In their case, defense counsel presented
    only three witnesses. The testimony of those witnesses
    was intended to establish that the petitioner had cut
    his hand at work, many hours after the crimes.
    Before the defense rested, counsel asked, outside the
    presence of the jury, for certain matters to be placed
    on the record. First, defense counsel notified the court
    that the petitioner had elected not to testify. The court
    confirmed with the petitioner that he understood that
    he had the right to testify, but did not want to do so.
    Second, defense counsel expressed their concern that,
    despite repeated discussions with the petitioner, most
    recently that same day, he had refused to accept their
    advice to allow them to present an affirmative defense
    in mitigation. They asked the court to confirm the peti-
    tioner’s decision. Before eliciting any statements from
    the petitioner, the court explained that it had no knowl-
    edge of the substance of the petitioner’s discussions
    with counsel and was not seeking such information, as
    the court should not be privy to such matters. The court
    then explained to the petitioner that the presentation
    of certain evidence could result in a conviction of a
    lesser degree of homicide and urged him to give serious
    consideration to counsel’s advice, pointing out that the
    court’s previous denial of defense counsel’s motion for
    a judgment of acquittal meant that there was sufficient
    evidence to present the capital felony and murder
    counts to the jury. The court took a short recess to
    afford the petitioner an opportunity to consult with
    counsel. When court reconvened, the petitioner con-
    firmed that he had had a chance to discuss all aspects
    of the case with counsel, and counsel confirmed that
    the defense had no further evidence to present. After
    the state rested, the court gave a charge to the jury
    that included an instruction that, if it found that the
    petitioner had acted under the influence of an extreme
    emotional disturbance for which there was a reasonable
    explanation or excuse, it could find the petitioner guilty
    of manslaughter in the first degree instead of murder.
    The jury returned a verdict of guilty of murder and
    capital felony.
    The first penalty phase proceeded before the same
    jury approximately five months later, at which time
    defense counsel presented evidence of mitigating fac-
    tors. Mitigating factors also were presented at the sec-
    ond penalty phase hearings heard by a three judge panel
    eight years later, following this court’s reversal of the
    judgment imposing the death sentence in the first pen-
    alty phase. The primary evidence came from two expert
    witnesses, Walter Borden, a psychiatrist who had con-
    ducted a forensic psychiatric evaluation of the peti-
    tioner, and Anne Phillips, a clinical psychologist who
    had administered a battery of psychological tests to
    the petitioner. Borden and Phillips both diagnosed the
    petitioner as suffering from a severe mixed personality
    disorder with borderline schizoid, paranoid, and
    depressive features. Both experts opined that, at the
    time of the offenses, the petitioner suffered from
    extreme emotional disturbance and his mental capacity
    was significantly impaired.
    Borden’s testimony was of particular significance.
    He had interviewed the petitioner on four occasions,
    beginning just two months after his arrest, in February,
    1988, and ending in December, 1988. Borden also elic-
    ited background information from certain members of
    the petitioner’s family, and reviewed psychological
    reports and certain public records pertaining to the
    petitioner. Those records included a presentence inves-
    tigation report relating to the petitioner’s conviction of
    manslaughter for killing his father twenty-one years
    before the petitioner killed his former wife and his son.
    Borden testified that the petitioner’s early childhood
    and adolescence were replete with horrific neglect,
    abuse and abandonment—some of the worst Borden
    had ever encountered—that had significantly affected
    the petitioner psychologically. Borden described those
    circumstances at length, which this court recounted in
    Breton I
    II, supra
    , 
    264 Conn. 340
    –42, 371–72. He
    described the petitioner’s father as a heavy drinker who
    was abusive and threatening toward the petitioner and
    others, and who routinely carried a knife. 
    Id., 342. Borden
    recounted the following information that he
    had elicited regarding the two events that are relevant
    to the petition presently before us, which we memorial-
    ized in Breton III: ‘‘On December 3, 1966, the [petition-
    er’s] father left the house to go drinking. It was later
    reported that, while out drinking, the [petitioner’s]
    father stated that the time had come to kill the [peti-
    tioner, who was then nineteen years old]. The [peti-
    tioner] was at home with his grandmother, who had just
    prepared a meal for them to eat, when the [petitioner’s]
    father came in, threatened the [petitioner], pushed the
    kitchen table against him and threw him up against the
    wall. The [petitioner] retreated into the bathroom to
    escape from his father and told his grandmother to
    call the police. The [petitioner’s] father then attacked
    [the] grandmother.
    ‘‘The [petitioner’s] memory about what happened
    next was not clear. Borden testified that the [petitioner]
    told him that he remembered picking up a knife and
    seeing his father fall, apparently hurt. The [petitioner]
    did not remember stabbing him, however. The [peti-
    tioner] then ran out of the house, found a police officer
    to whom he indicated that his father had been hurt and
    brought the officer back to the house. The [petitioner’s]
    father died of multiple stab wounds to the chest and
    face. Ultimately, the [petitioner] confessed to the kill-
    ing. He pleaded guilty to manslaughter and received a
    suspended sentence. Borden testified that the [peti-
    tioner] told him that he did not clearly recall stabbing
    his father, but admitted that he must have done so.
    ‘‘Shortly after the [petitioner] killed his father, he met
    his wife, JoAnn Breton. He married her in December,
    1967, within a few days of the first anniversary of his
    father’s death. The [petitioner] was very dependent on
    his wife for stability and psychological support, but
    their marriage was stormy. Borden testified that the
    [petitioner] was pathologically jealous of other men,
    paranoid and delusional, and that these conditions
    derived from a belief that he could not be loved and
    from a profound distrust of other people.’’ (Footnotes
    omitted.) 
    Id., 342–43. ‘‘When
    the [petitioner] was laid off [from his job in
    1985], he became depressed and started drinking heav-
    ily and taking pills. The relationship between him and
    his wife worsened. . . . Divorce proceedings were ini-
    tiated in July, 1986, and were finalized in January, 1987.
    ‘‘During this period the [petitioner] continued to
    become more depressed and to drink heavily. He also
    took the prescription drugs Desoxyn and Fiorinal.
    Desoxyn is an amphetamine with a potent stimulant
    effect. Borden testified that it was the worst medication
    that could have been prescribed for the [petitioner]
    because it would have exacerbated his depression and
    paranoia and could trigger violent behavior. He also
    testified that using the drug in combination with alcohol
    would be ‘like throwing gasoline’ on a simmering fire.
    ‘‘Borden testified that the [petitioner] reported to him
    that he was extremely depressed during the month of
    December, 1987. His birthday, the anniversary of his
    father’s death and his wedding anniversary all occurred
    in that month. It would have been his twentieth wedding
    anniversary that year. [He felt abandoned by the fact
    that his former wife and his son were planning to leave
    for Florida on December 17, and would be away for
    Christmas.] . . .
    ‘‘On December 12, 1987, the [petitioner] went to his
    former wife’s house in connection with one of [the
    various] tasks [that he had recently undertaken in the
    hopes of reconciling with her]. While there, he took her
    keys. That evening, the [petitioner] went to a bar. He
    met a woman there . . . and took her back to his
    house, where he attempted unsuccessfully to have sex-
    ual intercourse with her. At some point, he took the
    woman home and then returned to his own house. He
    then noticed the keys that he had taken from his former
    wife’s house and decided to return them to her and to
    try to talk to her. By then, it was very early in the
    morning of December 13.
    ‘‘Borden testified that his understanding of the events
    that happened next was based on [his first] interview
    with the [petitioner] on February 20, 1988.3 The [peti-
    tioner] told him that, as he parked the car in the parking
    lot [at] his former wife’s house, he thought that he saw
    someone walking around [outside].4 He then ‘strapped
    on’ a knife, went to the door and let himself in with
    the keys. [The petitioner was wearing gloves.] The [peti-
    tioner] reported to Borden that, at that time, he felt
    nervous, scared and unsure of himself. He laid the keys
    on an ironing board and then returned to the door,
    intending to leave. Instead, he went down into the base-
    ment. He did not know why. At some point, he went
    back up to the first floor and stood for a while. He then
    decided to go upstairs to his former wife’s bedroom.
    The [petitioner] reported to Borden that he still did not
    understand what he was doing. The [petitioner] entered
    his former wife’s bedroom, knelt on the bed and
    grabbed her. She screamed. The [petitioner] reported
    to Borden that he just wanted to talk to her at that
    point, but was unable to speak. His former wife then
    yelled, ‘Bobby, call the cops, somebody is hurting me.’
    ‘‘Borden testified that, at this point in the narrative
    . . . the [petitioner’s] demeanor changed dramatically.
    He began crying, sweating and trembling. In this agi-
    tated state, the [petitioner] reported to Borden that he
    had been trying to keep his former wife from yelling,
    not trying to hurt her. He recalled pushing her face
    down, wrestling on the bed with her and falling onto
    the floor. He found himself sitting on top of her and
    hitting her to keep her from yelling. She continued to
    scream to ‘Bobby’ that someone was trying to rape her.
    ‘‘At some point a light went on in the hall next to
    the bedroom. When the [petitioner] looked up he saw
    someone standing in the doorway. The [petitioner] did
    not know who it was. At that point, the [petitioner]
    took the knife in his hand. Borden testified that the
    [petitioner’s] description of his feelings at that time
    were ‘very similar [to those that he had described having
    at the time of] the death of his father where he described
    himself recalling, seeing the hand, his hand and the
    knife, not knowing what happened. . . . [I]t’s like he
    didn’t feel like he took the knife, he felt like his hand
    did it. It was a dissociative, it was not part of him.’
    ‘‘The [petitioner] reported to Borden that he did not
    recognize the person in the doorway. He said to his
    former wife that it was not ‘Bobby,’ but she said that
    it was. The person in the doorway then said something
    to the [petitioner]. The [petitioner] reported to Borden
    that he believed that the words were, ‘Dad, I love you.’
    At that point, the [petitioner] saw his own arm go out
    and hit the person in the doorway. He could not clearly
    see the person he was striking because the light was
    behind that person.
    ‘‘Borden testified that, during this part of the [peti-
    tioner’s] narrative to him, the [petitioner] was extremely
    emotional, trembling and crying and appeared to be
    racked and tormented by his recollection. Borden testi-
    fied that it was his impression that the [petitioner] was
    ‘back in that room’ as he reported the events. The [peti-
    tioner] reported that he hit the person in the doorway
    and saw something gushing out of his neck or head and
    heard something gasping and gurgling. At that point,
    the [petitioner] recognized his son.
    ‘‘The [petitioner] then heard his former wife calling
    him and he returned to the bedroom. She asked the
    [petitioner], ‘[W]hy, Bob?’ The [petitioner] then grabbed
    her hair and felt his hand hit her. He heard gurgling
    and then a crash. He left the bedroom and, as he started
    down the stairs, saw his son lying at the bottom of the
    stairs on the floor, shaking. At that point, he went back
    into the bedroom and knelt next to his former wife,
    who was lying on the floor and asked, ‘[W]hy, why.’ He
    told her that he just wanted to talk, but then he hit her
    with his hand again.
    ‘‘Borden testified that, at this point in the interview,
    the [petitioner] said, in reference to what happened
    next, ‘God, no, no, no, I didn’t do that.’ The [petitioner]
    reported that he left the bedroom and went back down-
    stairs. His son was lying dead at the bottom of the stairs
    with his eyes open and looking at the [petitioner]. The
    [petitioner] said to his son, ‘[T]hank you for the birthday
    card,’ and then stabbed him in the neck.5
    ‘‘Borden testified that, while the [petitioner] was
    reporting this portion of the narrative, he was saying,
    ‘[W]hy do I remember so much? Why do I have to
    remember?’ and ‘[W]hy, why, why.’ He also continued
    to cry and to be in an extreme emotional state. After
    describing his last act, however, his demeanor changed
    instantaneously, as if he had awoken from a nightmare.
    Borden testified that he could never persuade the [peti-
    tioner] to talk about the events surrounding the murders
    again. . . .
    ‘‘Borden testified that the [petitioner’s] experience
    of his hand as not being a part of himself was an example
    of the depersonalization that borderline personalities
    are prone to experience. Borden also testified that
    depersonalization is a defense mechanism developed
    by children who have been subjected to chronic severe
    abuse. As adults, such persons are prone to go into a
    dissociative state under severe stress.
    ‘‘Borden testified that, in his opinion, at the time
    of the offense, the [petitioner’s] ability to conform his
    conduct to the requirements of the law was significantly
    impaired; his mental functioning was significantly
    impaired; he suffered from a mental disease or defect,
    namely borderline personality disorder; and he was
    severely mentally ill. He also testified that the [peti-
    tioner] suffered from an extreme emotional disturbance
    at the time of the offense.’’ (Footnotes added.) 
    Id., 344–49. The
    three judge panel before which the second pen-
    alty phrase was heard made findings consistent with
    those found by the jury in the first penalty phase. The
    panel found that the state had proved beyond a reason-
    able doubt that the murders had been committed in an
    especially cruel manner. 
    Id., 335–36. The
    panel found
    that the petitioner had not proved that he suffered from
    an extreme emotional disturbance, but had proved
    other mitigating facts, including that he was neglected,
    abandoned and the product of an abusive family unit
    during his childhood. 
    Id., 336 and
    n.8. The panel con-
    cluded that none of the proven mitigating facts alone
    or in combination constituted mitigation. 
    Id., 336. In
    accordance with its findings, the panel imposed a sen-
    tence of death. 
    Id. The petitioner
    directly appealed from
    the judgment imposing this sentence to this court. 
    Id. While the
    appeal in Breton III was pending, the peti-
    tioner filed a petition for a new trial, claiming that two
    transcripts of the petitioner’s account of the 1966 killing
    of his father, which came to light for the first time
    during the state’s cross-examination of Borden at the
    second penalty phase hearing, constituted newly dis-
    covered evidence. One transcript was from a police
    interview conducted hours after the crime; the other
    was from the coroner’s inquest. The petition alleged that
    the transcripts would have led to a different outcome
    because the petitioner’s dissociated mental state
    reflected in the 1966 transcripts would have led Borden
    to diagnose the petitioner as having a significant dissoci-
    ated mental state at the time of the 1987 homicides
    that could have rendered him legally insane. This court
    continued the appeal in Breton III to allow that petition
    to proceed, after the petitioner argued that a hearing
    on the petition would provide a crucial factual underpin-
    ning for a related claim in the appeal. 
    Id., 354. New
    trial
    counsel ultimately withdrew that petition with preju-
    dice, following Borden’s clarification that further test-
    ing would be necessary to determine whether the
    petitioner was legally insane at the time of the offense.6
    
    Id. The appeal
    in Breton III proceeded, and this court
    affirmed the judgment imposing a sentence of death on
    the petitioner. 
    Id., 446. II
                        HABEAS TRIAL
    Some prefatory comments are necessary to explain
    the scope of our review of the habeas proceedings.
    After his judgment of conviction and sentence became
    final, the petitioner filed an amended petition for a writ
    of habeas corpus, claiming that constitutional errors
    had infected every stage of the criminal proceedings—
    guilt phase, second penalty phase, petition for a new
    trial, and appeal. The habeas court, Schuman, J., denied
    the petition. The petitioner appealed from that judg-
    ment to the Appellate Court, and then moved to transfer
    the appeal to this court.
    Following our grant of the motion to transfer, we
    issued our decision in State v. Santiago, 
    318 Conn. 1
    ,
    
    122 A.3d 1
    (2015), which effectively narrowed the issues
    that we must consider in the petitioner’s present habeas
    appeal. In Santiago, this court held that, in light of
    the 2012 public act prospectively repealing the death
    penalty; Public Acts 2012, No. 12-5; the execution of
    offenders who committed capital felonies prior to the
    act’s effective date would violate the state constitution’s
    prohibition against cruel and unusual punishment. State
    v. 
    Santiago, supra
    , 8–9. The parties in the present case
    agreed at oral argument before this court that Santiago
    rendered all of the petitioner’s claims challenging his
    sentence of death moot, as the petitioner is now entitled
    to seek to have his sentence corrected to life imprison-
    ment without the possibility of release. Therefore, the
    discussion of the habeas proceedings that follows is
    limited to the petitioner’s claims that relate to the judg-
    ment of conviction.
    In the operative petition, the petitioner asserted the
    following claims that are relevant to the present appeal.
    First, he alleged guilt phase counsel rendered ineffec-
    tive assistance by: (a) failing to discover the two 1966
    transcripts, which could have ultimately established
    that the petitioner suffered from PTSD with dissociative
    features during the 1987 crimes; (b) failing to test the
    blood sample taken from the petitioner approximately
    forty hours after the 1987 crimes (first blood sample),
    which had remained in the state’s file until discovered
    by habeas counsel, and which could have established
    that he suffered from methamphetamine (Desoxyn)
    intoxication during the commission of the offenses; and
    (c) presenting a marginal reasonable doubt defense to
    the exclusion of a meritorious extreme emotional dis-
    turbance defense. Second, he alleged that he had
    received ineffective assistance of counsel in his petition
    for a new trial because counsel had withdrawn the
    meritorious petition with prejudice. Third, the peti-
    tioner alleged that the cumulative effect of counsel’s
    deficient performance regarding the aforementioned
    matters constituted the prejudice necessary to establish
    ineffective assistance of counsel, as well as a violation
    of his right to due process. Fourth, the petitioner alleged
    that the state’s failure to disclose the 1966 transcripts
    constituted the suppression of material, exculpatory
    evidence in violation of Brady v. Maryland, 
    373 U.S. 83
    , 87, 
    83 S. Ct. 1194
    , 
    10 L. Ed. 2d 215
    (1963).
    Hearings on the habeas petition took place in 2011—
    twenty-four years after criminal trial counsel was
    appointed, and twenty-two years after the guilt phase
    of the criminal trial concluded.7 Although we explore
    the details of this evidence in part III of this opinion
    in our analysis of the petitioner’s specific claims, we
    briefly summarize that evidence to provide context for
    the habeas court’s decision.
    The petitioner proffered testimony from Alan
    McWhirter and Richard F. Kelly, who represented the
    petitioner at the guilt phase and the first penalty phase,
    as well as from the other attorneys whose performance
    at other stages of the criminal proceedings was alleged
    to be deficient. McWhirter and Kelly had little recall of
    the details of their communications with the petitioner
    and their investigatory strategies due to the exception-
    ally long time that had lapsed since they represented
    the petitioner. Defense counsel clearly recalled, how-
    ever, that the petitioner had consistently taken the posi-
    tion that he did not commit the crimes and had
    consistently refused to allow them to present any
    defense that would be tantamount to an admission that
    he had done so. They acknowledged that they had
    believed all along that a reasonable doubt defense had
    little chance of success. Nonetheless they pursued that
    strategy because (1) they believed that the petitioner
    had the right to decide whether to effectively admit
    that he had committed manslaughter, and (2) the peti-
    tioner had suggested that he would take the stand to
    deny having committed the crimes if counsel put on
    evidence suggesting that he had done so. Defense coun-
    sel did not believe that they had specifically discussed
    PTSD with the petitioner, but they recalled discussing
    the petitioner’s drug and alcohol abuse. McWhirter testi-
    fied that defense counsel had recognized that intoxica-
    tion ‘‘would possibly be a defense we could raise
    depending on whether it was intention[al], uninten-
    tional, or whatever. Obviously it never got raised
    because [the petitioner] would not let us go in that
    direction.’’
    The petitioner also proffered documentary evidence
    and expert witnesses. The petitioner presented expert
    opinion that the 1966 transcripts would have provided
    significant evidence that the petitioner was in a dissoci-
    ative state when he killed his father, which was reflec-
    tive of PTSD resulting from prior childhood trauma.
    The experts further opined that this evidence, in combi-
    nation with the petitioner’s account of the 1987 crimes
    to Borden and subsequent interviews or testing, demon-
    strated that he suffered from PTSD with dissociative
    features during the commission of the 1987 crimes.
    The petitioner also presented expert testimony
    extrapolating, on the basis of the level of methamphet-
    amine detected when habeas counsel tested the first
    blood sample in 2005: (a) a range of the level of the
    drug in the petitioner’s system when the blood was
    drawn in 1987; and (b) from that range, a range of the
    level of the drug in his system forty hours earlier when
    he committed the crimes. The petitioner presented
    expert opinion that levels in this range would have
    caused the petitioner to suffer methamphetamine intox-
    ication.8 One of the petitioner’s experts, Neil Blumberg,
    a psychiatrist, opined that the petitioner had six mental
    disorders at the time of the crimes—chronic PTSD,
    depressive disorder not otherwise specified, amphet-
    amine intoxication, amphetamine abuse, alcohol depen-
    dence, and personality disorder not otherwise specified
    with borderline features—that collectively had caused
    an extreme emotional disturbance. Another expert,
    Pablo Stewart, a psychiatrist, opined that the exacerbat-
    ing effect of methamphetamine intoxication on preex-
    isting PTSD or the methamphetamine intoxication
    alone had caused an extreme emotional disturbance at
    the time of the crimes.
    Finally, the petitioner presented testimony from an
    experienced capital defense attorney that competent
    counsel defending such cases would have investigated
    these matters. This expert opined that counsel should
    not acquiesce to a defendant’s wishes whether to pre-
    sent such evidence, and should make continuous efforts
    to persuade a defendant to present such evidence.
    The respondent, the Commissioner of Correction,
    proffered numerous exhibits relating to defense coun-
    sel’s investigation and presented his own toxicology
    experts on methamphetamine intoxication. Those
    experts opined that, because of various factors, a single,
    eighteen year old blood sample could not yield evidence
    to reliably establish a level of methamphetamine in a
    person’s system forty hours before it had been drawn.
    The respondent did not offer any experts on PTSD, but
    he cross-examined the petitioner’s experts as to the
    foundation of their opinions.
    Notably, the petitioner did not testify at the habeas
    trial. Indeed, his habeas experts testified that the peti-
    tioner still maintained that he did not commit the crimes
    and would become so angry and defensive if any
    attempt was made to probe into that matter that they
    were forced to rely on his lone account of the crimes
    to Borden to make a diagnosis. The petitioner also did
    not offer Borden or Phillips as habeas witnesses to
    explain whether the transcripts or blood test would
    have affected their opinions.
    The habeas court determined that counsel had ren-
    dered deficient performance in two respects, but that
    neither deficiency had prejudiced the petitioner in light
    of the position he had taken regarding his defense. The
    court deemed McWhirter and Kelly to have performed
    deficiently for failing to discover the 1966 transcripts
    containing the petitioner’s firsthand account of his
    father’s death. The court found that although defense
    counsel first became aware of the transcripts when
    the state’s attorney raised them while cross-examining
    Borden at the second penalty phase, the transcripts
    had been available to counsel in materials set aside as
    relevant to the 1987 crimes in the state’s attorney’s
    office. As to the significance of this evidence, the court
    agreed with defense counsel’s assessment that the prior
    homicide was in part a ‘‘ ‘wild card,’ ’’ insofar as the
    prosecution could benefit from evidence that the peti-
    tioner had previously killed someone. The court found
    that the balance weighed in favor of full investigation,
    however, because the crimes had substantial similari-
    ties (irrationally slaying an immediate family member),
    and the circumstances of the 1966 crime (suspended
    sentence and probation on a charge of manslaughter)
    suggested a bona fide defense.
    Nonetheless, the court determined that the petitioner
    had not established prejudice because there was not a
    reasonable probability that the result would have been
    different had this evidence been available. The court
    found that ‘‘the petitioner was a difficult and opposi-
    tional client who maintained, despite strong evidence
    to the contrary, that he did not commit the killings.
    Although first trial counsel thought their best defense
    was extreme emotional disturbance, because it would
    reduce murder to manslaughter and thereby eliminate
    a possible death sentence, for this defense to succeed
    the petitioner would have to acknowledge his actions
    in causing the victims’ deaths. The petitioner would not
    make that acknowledgment.’’ (Footnote omitted.) Not
    only that, but the petitioner had specifically forbidden
    counsel to assert a defense on this basis.
    The court noted that criminal trial counsel had repeat-
    edly attempted to change the petitioner’s mind, and
    that attempting to override his decision was risky as a
    general proposition and particularly so in the present
    case. The court noted that it would be difficult to pre-
    sent the defense without the petitioner’s testimony
    admitting to the killings. There was nothing that would
    indicate that the petitioner would be willing to do so,
    whereas counsel had expressed a legitimate concern
    that the petitioner would take the stand and deny the
    killings. That action might not only negate the extreme
    emotional disturbance defense, but also would allow
    the state to impeach the petitioner with his prior admis-
    sion to Borden. As such, the court reasoned that overrid-
    ing the petitioner’s decision might not only doom the
    effect of the evidence at the guilt phase, but also nega-
    tively impact the jurors’ perceptions for purposes of
    the penalty phase.
    The habeas court also found counsel deficient for
    failing to test the blood sample for evidence of intoxica-
    tion. The court could perceive of no strategic reason
    not to test the sample given the petitioner’s drug abuse
    and the possibility that drug use could support a claim
    of intoxication or be a mitigating factor at the penalty
    phase, and counsel had provided none. The court agreed
    with the petitioner that a blood test for drugs is the
    ‘‘ ‘gold standard.’ ’’
    Nonetheless, the court found that the petitioner was
    not prejudiced by counsel’s failure to test the sample
    because he would not have permitted counsel to proffer
    that evidence. The court reasoned: ‘‘At the guilt phase,
    the assertion of intoxication evidence essentially repre-
    sented a concession by the petitioner that, although he
    was intoxicated at the time, he nonetheless committed
    the killings. . . . The court credits the testimony of
    McWhirter that the petitioner refused to allow first trial
    counsel to take this approach. Drug testing . . . would
    not likely have changed the petitioner’s mind; the peti-
    tioner knew that his attorneys had abundant nonscien-
    tific evidence of the petitioner’s drug and alcohol abuse,
    yet he still opposed presenting evidence of intoxica-
    tion.’’ In its discussion of the penalty phase, the court
    also found that the petitioner’s habeas experts had not
    established that the petitioner took an intoxicating dose
    at the critical time before the murders, but rather had
    relied on one uncertainty after another.
    In light of its resolution of the aforementioned claims,
    the habeas court summarily rejected the petitioner’s
    remaining claims of ineffective assistance of guilt phase
    counsel, a Brady violation, and cumulative error. The
    court deemed the petitioner’s stand regarding his
    unwillingness to admit to the killings to preclude a claim
    that counsel was ineffective for presenting a marginal
    reasonable doubt defense to the exclusion of a meritori-
    ous extreme emotional disturbance defense. The court
    concluded that the state had not suppressed the 1966
    transcripts, but even if it had, the petitioner’s Brady
    claim would fail because the materiality standard set
    forth in Brady is the same as the prejudice component
    of the ineffective assistance of counsel standard. As to
    cumulative error, whether framed as ineffective assis-
    tance of counsel or due process, the habeas court con-
    cluded that such a claim is not cognizable under
    Connecticut appellate case law.
    Finally, the court rejected the petitioner’s claim that
    he had received ineffective assistance of counsel in
    connection with his petition for a new trial.9 The court
    concluded that, because there is no statutory or consti-
    tutional right to counsel in connection with a petition
    for a new trial, the petitioner had no right to effective
    assistance of counsel. Accordingly, the habeas court
    denied the petitioner’s amended petition for a writ of
    habeas corpus. This appeal followed.
    III
    APPEAL
    The petitioner challenges the habeas court’s factual
    finding that he rejected the presentation of evidence of
    intoxication and the court’s legal conclusions as to all
    of his claims. In reviewing these claims, we are mindful
    that ‘‘[t]he habeas court is afforded broad discretion in
    making its factual findings, and those findings will not
    be disturbed unless they are clearly erroneous. . . .
    The application of the habeas court’s factual findings
    to the pertinent legal standard, however, presents a
    mixed question of law and fact, which is subject to
    plenary review.’’ (Internal quotation marks omitted.)
    Horn v. Commissioner of Correction, 
    321 Conn. 767
    ,
    775, 
    138 A.3d 908
    (2016).
    A
    Ineffective Assistance of Counsel at the Guilt Phase
    A fundamental premise of the petitioner’s challenge
    to the habeas court’s decision is that neither his state-
    ments rejecting a defense of extreme emotional distur-
    bance nor his refusal to admit that he committed the
    crimes precludes relief. Citing Wiggins v. Smith, 
    539 U.S. 510
    , 
    123 S. Ct. 2527
    , 
    156 L. Ed. 2d 471
    (2003), the
    petitioner contends that because guilt phase counsel
    failed to undertake a reasonable investigation, which
    would have uncovered the 1966 transcripts and
    included testing the blood sample, neither counsel nor
    the petitioner were able to make an informed strategic
    choice as to how to proceed. The petitioner asserts that
    his refusal to mount an extreme emotional disturbance
    defense was limited to the only theory that counsel had
    investigated and were prepared to present, namely, that
    he had a mixed personality disorder that caused him to
    be depressed and pathologically jealous. The petitioner
    contends that this defense simply described his state
    of mind, whereas a defense based on PTSD and intoxi-
    cation would have explained the cause of his violent
    conduct. Finally, he contends that his testimony would
    not have been required to advance an extreme emo-
    tional disturbance defense, and even if he had insisted
    upon denying that he had committed the crimes, that
    action could have reinforced a defense based on an
    impaired mental state.
    The respondent challenges the habeas court’s conclu-
    sions that guilt phase counsel’s performance was defi-
    cient with regard to either the transcripts or the blood
    sample. In addition to arguing that there were valid
    tactical reasons for defense counsel’s inaction as to
    those two matters, the respondent argues that PTSD is
    simply a new diagnosis by new experts based on the
    same information on which the criminal trial experts
    based their opinions, which establishes neither defi-
    cient performance nor prejudice. The respondent
    defends the habeas court’s determination that the peti-
    tioner’s actions preclude him from establishing the prej-
    udice necessary to obtain habeas relief. He further
    argues that Schriro v. Landrigan, 
    550 U.S. 465
    , 
    127 S. Ct. 1933
    , 
    167 L. Ed. 2d 836
    (2007), forecloses the
    petitioner’s argument that his actions were immaterial
    in the absence of an informed, knowing and voluntary
    waiver of the specific evidence that he now claims
    should have been presented.
    We limit our analysis to the question of prejudice, as
    that issue is dispositive. We conclude that a client’s
    resolute, unambiguous instruction not to present miti-
    gating evidence, if made knowingly and voluntarily, can
    preclude a showing of prejudice from counsel’s failure
    to investigate mitigating evidence. We further conclude,
    largely for the reasons set forth by the habeas court,
    that this standard was met in the present case.
    The petitioner’s challenges to the effectiveness of
    counsel are governed by certain well settled principles.
    ‘‘To succeed on a claim of ineffective assistance of
    counsel, a habeas petitioner must satisfy the two-
    pronged test articulated in Strickland v. Washington,
    
    466 U.S. 668
    , 687, 
    104 S. Ct. 2052
    , 
    80 L. Ed. 2d 674
    (1984). Strickland requires that a petitioner satisfy both
    a performance prong and a prejudice prong. To satisfy
    the performance prong, a claimant must demonstrate
    that counsel made errors so serious that counsel was
    not functioning as the counsel guaranteed . . . by the
    [s]ixth [a]mendment. [Id.] To satisfy the prejudice
    prong, a claimant must demonstrate that there is a rea-
    sonable probability that, but for counsel’s unprofes-
    sional errors, the result of the proceeding would have
    been different. 
    Id., 694.’’ (Internal
    quotation marks omit-
    ted.) Small v. Commissioner of Correction, 
    286 Conn. 707
    , 712–13, 
    946 A.2d 1203
    , cert. denied sub nom. Small
    v. Lantz, 
    555 U.S. 975
    , 
    129 S. Ct. 481
    , 
    172 L. Ed. 2d 336
    (2008). Although a petitioner can succeed only if he
    satisfies both prongs, a reviewing court can find against
    a petitioner on either ground. See 
    id., 713; see
    also
    Strickland v. 
    Washington, supra
    , 697 (court need not
    determine whether counsel’s performance was defi-
    cient before examining prejudice suffered by
    defendant).
    ‘‘[S]trategic choices made after less than complete
    investigation are reasonable precisely to the extent that
    reasonable professional judgments support the limita-
    tions on investigation. In other words, counsel has a
    duty to make reasonable investigations or to make a
    reasonable decision that makes particular investiga-
    tions unnecessary.’’ Strickland v. 
    Washington, supra
    ,
    
    466 U.S. 690
    –91. Thus, in Wiggins v. 
    Smith, supra
    , 
    539 U.S. 524
    –28, on which the petitioner relies, the United
    States Supreme Court held that although defense coun-
    sel was aware of certain aspects of the defendant’s
    background, counsel’s failure to compile a complete
    social history of the defendant was objectively unrea-
    sonable and, thus, counsel rendered deficient perfor-
    mance by failing to make a fully informed decision when
    deciding against presenting such mitigation evidence.
    The Supreme Court has recognized, however, that
    ‘‘[t]he reasonableness of counsel’s actions may be deter-
    mined or substantially influenced by the defendant’s
    own statements or actions. Counsel’s actions are usu-
    ally based, quite properly, on informed strategic choices
    made by the defendant and on information supplied by
    the defendant. In particular, what investigation deci-
    sions are reasonable depends critically on such informa-
    tion.’’ Strickland v. 
    Washington, supra
    , 
    466 U.S. 691
    .
    Nonetheless, a defendant’s refusal to assist in dis-
    covering certain evidence does not relieve counsel of
    his or her obligation to investigate and seek such evi-
    dence from other sources. See Rompilla v. Beard, 
    545 U.S. 374
    , 377, 
    125 S. Ct. 2456
    , 
    162 L. Ed. 2d 360
    (2005)
    (counsel’s decision not to review court file of defen-
    dant’s prior convictions that counsel knew prosecution
    would probably rely on as evidence of aggravation and
    that revealed mitigating evidence, was objectively
    unreasonable ‘‘even when a capital defendant’s family
    members and the defendant himself have suggested that
    no mitigating evidence is available’’).
    Although the foregoing considerations are familiar
    to this court, we have not previously considered how
    these general principles apply when a defendant has
    refused to allow counsel to present mitigating evidence,
    and has even gone so far as to suggest that he would
    attempt to derail the presentation of such evidence if
    pressed. Other courts have confronted this situation,
    albeit principally in the context of the penalty phase of
    capital cases. Those courts have recognized that when
    a defendant instructs counsel not to investigate or pre-
    sent mitigating evidence, the scope of counsel’s duty
    to investigate may be more limited. Cummings v. Secre-
    tary for the Dept. of Corrections, 
    588 F.3d 1331
    , 1358–59
    (11th Cir. 2009), cert. denied sub nom. Cummings-El
    v. McNeil, 
    562 U.S. 872
    , 
    131 S. Ct. 173
    , 
    178 L. Ed. 2d 103
    (2010); see also Jeffries v. Blodgett, 
    5 F.3d 1180
    ,
    1198 (9th Cir. 1993) (‘‘[C]ounsel’s acquiescence in [the
    defendant’s] decision did not constitute deficient per-
    formance. Although the [A.B.A., Standards for Criminal
    Justice (2d Ed. 1980)] offers some support to [the defen-
    dant’s] contention that his counsel should have pre-
    sented evidence in mitigation despite his client’s wishes
    to the contrary, [those standards] serve only as a guide
    for determining whether an attorney’s performance is
    adequate.’’ [Internal quotation marks omitted.]), cert.
    denied, 
    510 U.S. 1191
    , 
    114 S. Ct. 1294
    , 
    127 L. Ed. 2d 647
    (1994). ‘‘This does not mean that a defendant’s
    instructions as to investigation or presentation of miti-
    gating evidence should be ‘blindly followed’ where the
    defendant has a possible mental impairment or the
    defendant’s instructions are not explicit or are less than
    clear.’’ Cummings v. Secretary for the Dept. of Correc-
    
    tions, supra
    , 1358. ‘‘The reason lawyers may not blindly
    follow such commands is that although the decision
    whether to use such evidence is for the client, the lawyer
    must first evaluate potential avenues and advise the
    client of those offering potential merit.’’ (Internal quota-
    tion marks omitted.) Adams v. Quarterman, 324 Fed.
    Appx. 340, 347 (5th Cir. 2009).
    ‘‘A competent defendant’s clear instruction not to
    investigate or present mitigation evidence also impacts
    the prejudice prong of the ineffective assistance test.’’
    Cummings v. Secretary for the Dept. of Correc
    tions, supra
    , 
    588 F.3d 1359
    . In Schriro v. 
    Landrigan, supra
    ,
    
    550 U.S. 469
    –70, the United States Supreme Court con-
    fronted a situation in which the defendant, Jeffrey Lan-
    drigan, had actively interfered with counsel’s efforts to
    elicit mitigating evidence from two witnesses whose
    testimony defense counsel sought to present, Landri-
    gan’s former wife and his birth mother. Upon ques-
    tioning by the trial court, Landrigan affirmed that he had
    instructed his counsel not to present ‘‘ ‘any’ ’’ mitigating
    evidence. 
    Id., 469. At
    the conclusion of the sentencing
    hearing, when Landrigan was permitted to speak, he
    ‘‘made a brief statement that concluded, ‘I think if you
    want to give me the death penalty, just bring it right
    on. I’m ready for it.’ ’’ 
    Id., 470. Landrigan
    thereafter
    sought habeas relief on the ground that his counsel
    should have investigated the ‘‘ ‘biological component’ ’’
    of his violent behavior resulting from his mother’s use
    of drugs and alcohol while pregnant with him and from
    family history. 
    Id., 471. A
    closely divided Supreme Court
    held that the defendant was not entitled to an eviden-
    tiary hearing on his claim of ineffective assistance
    because, in light of Landrigan’s instruction and conduct,
    counsel’s failure to investigate further could not have
    been prejudicial under Strickland. 
    Id., 475. The
    court explained that ‘‘[n]either Wiggins nor
    Strickland addresses a situation in which a client inter-
    feres with counsel’s efforts to present mitigating evi-
    dence to a sentencing court. Wiggins [v. 
    Smith, supra
    ,
    
    539 U.S. 523
    ] (‘[w]e focus on whether the investigation
    supporting counsel’s decision not to introduce mitigat-
    ing evidence of [the defendant’s] background was itself
    reasonable’ . . .). Indeed, we have never addressed a
    situation like this. In Rompilla v. Beard, [supra, 
    545 U.S. 381
    ] . . . the defendant refused to assist in the
    development of a mitigation case, but did not inform
    the court that he did not want mitigating evidence pre-
    sented.’’ (Emphasis in original.) Schriro v. 
    Landrigan, supra
    , 
    550 U.S. 478
    .
    The majority rejected, in turn, the reasons cited by
    the United States Court of Appeals for the Ninth Circuit
    in support of its conclusion that Landrigan was entitled
    to an evidentiary hearing to establish ineffective assis-
    tance. The majority first rejected the Ninth Circuit’s
    primary determination that Landrigan could not have
    intended to preclude all mitigating evidence, even that
    about which he could not have known due to counsel’s
    failure to investigate. 
    Id., 476. The
    majority concluded
    that much of the evidence that Landrigan claimed
    should have been investigated overlapped with the evi-
    dence that counsel had sought to present. 
    Id. The major-
    ity noted that counsel had attempted to call Landrigan’s
    birth mother to testify about her ‘‘ ‘drug us[e] during
    her pregnancy’ . . . and the possible effects of such
    drug use.’’ (Citation omitted.) 
    Id. The majority
    also
    pointed to Landrigan’s disruptive conduct when counsel
    tried to proffer anything that could have been consid-
    ered mitigating as clear evidence ‘‘that Landrigan would
    have undermined the presentation of any mitigating
    evidence that his attorney might have uncovered.’’ 
    Id., 477. The
    majority did not directly respond to the four
    dissenting justices’ criticism that it had not addressed
    the lack of neuropsychological information available to
    Landrigan at the time of his purported waiver, which
    could have established that Landrigan suffered from
    an organic brain disorder. 
    Id., 482, 489
    (Stevens, J.,
    dissenting). The dissent argued that even if Landrigan
    knew all of the facts in his history that had led to this
    diagnosis, the court could not ‘‘assume that he could
    understand their consequences the way an expert psy-
    chologist could.’’ 
    Id., 491 (Stevens,
    J., dissenting).
    The majority, however, did respond to the Ninth Cir-
    cuit’s decision to grant relief on the grounds ‘‘that the
    record does not indicate that Landrigan’s decision not
    to present mitigating evidence was ‘informed and know-
    ing’ . . . and that ‘[t]he trial court’s dialogue with Lan-
    drigan tells us little about his understanding of the
    consequences of his decision . . . .’ ’’ (Citations omit-
    ted.) 
    Id., 478–79. The
    court explained: ‘‘We have never
    imposed an ‘informed and knowing’ requirement upon
    a defendant’s decision not to introduce evidence. Cf.,
    e.g., Iowa v. Tovar, 
    541 U.S. 77
    , 88 [
    124 S. Ct. 1379
    , 
    158 L. Ed. 2d 209
    ] (2004) (explaining that waiver of the
    right to counsel must be knowing and intelligent). Even
    assuming, however, that an ‘informed and knowing’
    requirement exists in this case, Landrigan cannot bene-
    fit from it, for three reasons.
    ‘‘First, Landrigan never presented this claim to the
    Arizona courts. . . . Second, in Landrigan’s presence,
    his counsel told the sentencing court that he had care-
    fully explained to Landrigan the importance of mitigat-
    ing evidence, ‘especially concerning the fact that the
    [s]tate is seeking the death penalty.’ . . . Counsel also
    told the court that he had explained to Landrigan that as
    counsel, he had a duty to disclose ‘any and all mitigating
    factors . . . to th[e] [c]ourt for consideration regard-
    ing the sentencing.’ . . . In light of Landrigan’s demon-
    strated propensity for interjecting himself into the
    proceedings, it is doubtful that Landrigan would have
    sat idly by while his counsel lied about having pre-
    viously discussed these issues with him. And as Landri-
    gan’s counsel conceded at oral argument before this
    [c]ourt, we have never required a specific colloquy to
    ensure that a defendant knowingly and intelligently
    refused to present mitigating evidence. . . . Third, the
    Court of Appeals overlooked Landrigan’s final state-
    ment to the sentencing court: ‘I think if you want to
    give me the death penalty, just bring it right on. I’m
    ready for it.’ . . . It is apparent from this statement
    that Landrigan clearly understood the consequences of
    telling the judge that, ‘as far as [he was] concerned,’
    there were no mitigating circumstances of which she
    should be aware.’’10 (Citations omitted; footnote omit-
    ted.) Schriro v. 
    Landrigan, supra
    , 
    550 U.S. 479
    –80.
    In assessing the impact of Schriro on the present
    case, two distinctions from the present case bear noting.
    First, Schriro and case law from lower courts on this
    subject involve mitigation evidence in the penalty phase
    of a capital case, wherein the absence of such evidence
    made it exceedingly likely that the defendant would
    be sentenced to death. Thus, the eighth amendment
    concerns informing the standards imposed in those
    cases do not apply to the present case. See, e.g., Hamil-
    ton v. Ayers, 
    583 F.3d 1100
    , 1113 (9th Cir. 2009)
    (‘‘[b]ecause [t]he [c]onstitution prohibits imposition of
    the death penalty without adequate consideration of
    factors which might evoke mercy . . . [i]t is imperative
    that all relevant mitigating information be unearthed for
    consideration at the capital sentencing phase’’ [citations
    omitted; internal quotation marks omitted]).
    Second, Schriro involved the highly deferential
    review of state proceedings under the Antiterrorism
    and Effective Death Penalty Act of 1996 (federal act),
    Pub. L. No. 104-132, 110 Stat. 1214. Schriro v. Landri-
    
    gan, supra
    , 
    550 U.S. 473
    . Under the federal act, reversal
    of a state court’s adjudication is permitted only if that
    adjudication ‘‘resulted in a decision that was contrary
    to, or involved an unreasonable application of, clearly
    established [f]ederal law, as determined by the Supreme
    Court of the United States . . . or the relevant state-
    court decision was based on an unreasonable determi-
    nation of the facts in light of the evidence presented in
    the [s]tate court proceeding . . . .’’ (Citations omitted;
    internal quotation marks omitted.) 
    Id. Thus, the
    ques-
    tion in Schriro was whether the Supreme Court pre-
    viously had held that a defendant’s decision not to
    present mitigating evidence must be knowing and vol-
    untary, not whether it would so hold if that question
    were presented to it. Indeed, the court went on to decide
    whether the waiver reasonably could be viewed as
    knowing and voluntary if such a standard applied.
    Clearly, the four dissenting justices believed that such
    a standard previously had been established. Moreover,
    although the federal act may preclude a federal court
    from overturning a state court’s decision on the ground
    that the waiver of mitigation evidence was not informed
    and knowing; see, e.g., Cowans v. Bagley, 
    639 F.3d 241
    ,
    246–47 (6th Cir. 2011); that scheme does not constrain
    this court’s resolution of that question.
    A survey of case law preceding and postdating
    Schriro reveals that most courts have applied some
    sort of knowing and voluntary standard, expressly or
    implicitly, when evaluating the effect of a defendant’s
    refusal to allow the presentation of mitigating evidence
    at the capital sentencing phase on either (a) the effec-
    tiveness of counsel or (b) the validity of a waiver of
    the right to present mitigating evidence.11 See Brawner
    v. Epps, 439 Fed. Appx. 396, 402–408 (5th Cir. 2011)
    (whether waiver of right to present mitigation case is
    knowing and voluntary is component of analysis of
    ineffective assistance of counsel claim), cert. denied,
    U.S.     , 
    132 S. Ct. 2375
    , 
    182 L. Ed. 2d 1025
    (2012);
    Blystone v. Horn, 
    664 F.3d 397
    , 423–26 (3d Cir. 2011)
    (concluding that state court unreasonably concluded
    that facts demonstrated that defendant made ‘‘ ‘know-
    ing, intelligent, and voluntary’ waiver of his right to
    present any mitigating evidence at sentencing’’ [empha-
    sis in original]); Allen v. Secretary, Florida Dept. of
    Corrections, 
    611 F.3d 740
    , 763–64 (11th Cir. 2010) (not-
    ing in review of state court’s decision that Schriro fore-
    closed argument that defendant’s waiver of mitigation
    case should be deemed invalid because, due to lack
    of investigation, counsel failed to inform defendant of
    evidence he was giving up, but nonetheless explaining
    why waiver was knowing and intelligent), cert. denied
    sub nom. Allen v. Buss, 
    563 U.S. 976
    , 
    131 S. Ct. 2898
    ,
    
    179 L. Ed. 2d 1192
    (2011); Hamilton v. 
    Ayers, supra
    ,
    
    583 F.3d 1118
    –19 (defendant’s decision not to allow
    presentation of mitigating evidence can excuse coun-
    sel’s failure to present such evidence when defendant’s
    decision is knowing, voluntary, and intelligent);12 Cole-
    man v. Mitchell, 
    268 F.3d 417
    , 447–49 (6th Cir. 2001)
    (counsel’s effectiveness in connection with defendant’s
    instruction not to present mitigating evidence deter-
    mined in light of whether defendant’s decision was
    knowing and informed); Battenfield v. Gibson, 
    236 F.3d 1215
    , 1231–34 (10th Cir. 2001) (counsel rendered inef-
    fective assistance in failing to conduct adequate investi-
    gation despite defendant’s instruction not to present
    any mitigating evidence because waiver was not know-
    ing and intelligent); Chandler v. Greene, Docket No. 97-
    27, 
    1998 WL 279344
    , *8 (4th Cir. May 20, 1998) (affirming
    district court’s conclusion that counsel was not ineffec-
    tive for following defendant’s knowing and voluntary
    decision to forgo presentation of mitigating evidence
    to jury) (decision without published opinion, 
    145 F.3d 1323
    [4th Cir. 1998]), cert. denied, 
    524 U.S. 974
    , 119 S.
    Ct. 23, 
    141 L. Ed. 2d 783
    (1998); Emerson v. Gramley,
    
    91 F.3d 898
    , 906–907 (7th Cir. 1996) (defendant’s waiver
    of right to present mitigating evidence was not knowing
    waiver to which he could be held in light of counsel’s
    failure to conduct any investigation into mitigating evi-
    dence), cert. denied sub nom. Emerson v. Gilmore, 
    520 U.S. 1122
    , 
    117 S. Ct. 1260
    , 
    137 L. Ed. 2d 339
    (1997), cert.
    denied sub nom. Gilmore v. Emerson, 
    520 U.S. 1139
    , 
    117 S. Ct. 1289
    , 
    137 L. Ed. 2d 364
    (1997); Snell v. Lockhart,
    
    14 F.3d 1289
    , 1302–1303 (8th Cir.) (defendant validly
    waived right to present mitigating evidence because
    choice was informed, voluntary, and intelligent), cert.
    denied sub nom. Snell v. Norris, 
    513 U.S. 960
    , 
    115 S. Ct. 419
    , 
    130 L. Ed. 2d 334
    (1994); see also Commonwealth v.
    Rega, 
    593 Pa. 659
    , 711, 
    933 A.2d 997
    (2007) (‘‘[C]ertain
    jurisdictions require capital counsel to conduct an
    investigation into potential mitigation evidence to
    ensure that a defendant’s waiver of such proof is know-
    ing and intelligent. . . . Pennsylvania, however, aligns
    with those states that do not so require, demanding
    only that the defendant’s waiver be knowing, intelligent,
    and voluntary.’’ [Citation omitted.]), cert. denied, 
    552 U.S. 1316
    , 
    128 S. Ct. 1879
    , 
    170 L. Ed. 2d 755
    (2008).
    Precisely what such a standard requires appears to
    be context specific. Certain common factors can be
    gleaned from the jurisdictions that have applied this
    standard, however, which are consistent with those
    that Schriro indicated would apply if a knowing and
    intelligent waiver of mitigating evidence was constitu-
    tionally required. The record must establish that the
    defendant clearly and unequivocally expressed an inten-
    tion not to present any mitigating evidence (or to limit
    the mitigation evidence). See Schriro v. 
    Landrigan, supra
    , 
    550 U.S. 475
    –76; Blystone v. 
    Horn, supra
    , 
    664 F.3d 425
    –26 (concluding that defendant’s statement
    declining to ‘‘ ‘offer any other evidence’ ’’ did not sug-
    gest that defendant intended to preclude all mitigation
    evidence when read in context and when record estab-
    lished no basis to conclude that counsel had discussed
    mitigation evidence other than through testimony of
    defendant and his parents); Loden v. McCarty, 
    778 F.3d 484
    , 498–500 (5th Cir.) (record established ‘‘firm,’’ ‘‘con-
    sidered,’’ ‘‘resolute’’ decision not to present any mitiga-
    tion evidence), cert. denied sub nom. Loden v. Fisher,
    U.S.     , 
    136 S. Ct. 402
    , 
    193 L. Ed. 2d 315
    (2015);
    Young v. Sirmons, 
    551 F.3d 942
    , 959 (10th Cir. 2008)
    (‘‘[W]e find it impossible to predict with any degree of
    certainty what [the defendant] would have done had
    his trial counsel investigated and prepared to present all
    of the available mitigating evidence that [the defendant]
    now points to. In particular, we do not believe that [his]
    decision to [forgo] the live testimony of his friends and
    family members allows us to accurately predict what
    he would have done had his trial counsel planned to
    present mitigating testimony from [certain experts].’’),
    cert. denied, 
    558 U.S. 906
    , 
    130 S. Ct. 272
    , 
    175 L. Ed. 2d 183
    (2009).
    The record must also reflect that the defendant under-
    stood that he had the right to present mitigating evi-
    dence, the nature of the mitigating evidence, and the
    consequences of failing to present such evidence.
    Schriro v. 
    Landrigan, supra
    , 
    550 U.S. 479
    –80; see also
    Coleman v. 
    Mitchell, supra
    , 
    268 F.3d 447
    (defendant
    must know ‘‘meaning of mitigation evidence and the
    availability of possible mitigation strategies’’ and have
    ‘‘understanding of competing mitigation strategies’’
    [internal quotation marks omitted]); Battenfield v. Gib-
    
    son, supra
    , 
    236 F.3d 1230
    –31 (waiver was not valid
    when petitioner instructed as to right but did not have
    understanding of general nature of mitigating evidence
    or specific types of mitigation evidence that might be
    available). This does not mean that the defendant must
    be fully informed about the specifics of the mitigation
    evidence. A higher standard would be inconsistent with
    Schriro and the United States Supreme Court’s waiver
    jurisprudence generally. See United States v. Ruiz, 
    536 U.S. 622
    , 629, 
    122 S. Ct. 2450
    , 
    153 L. Ed. 2d 586
    (2002)
    (‘‘the law ordinarily considers a waiver knowing, intelli-
    gent, and sufficiently aware if the defendant fully under-
    stands the nature of the right and how it would likely
    apply in general in the circumstances—even though the
    defendant may not know the specific detailed conse-
    quences of invoking it’’ [emphasis omitted]); see also
    United States v. Demeke, Docket No. 96-1413, 
    1998 WL 391051
    , *2 (2d Cir. May 20, 1998) (rejecting argument
    that district court had obligation to conduct full inquiry
    into applicability of diminished capacity defense to cir-
    cumstances of case before allowing defendant to forgo
    defense in contravention to advice of counsel) (decision
    without published opinion, 
    152 F.3d 921
    [2d Cir. 1998]).
    Finally, although Schriro did not expressly address
    this concern, there is consensus that counsel may not
    acquiesce to such an instruction when there is evidence
    the defendant is not competent to make such a decision.
    See, e.g., Brawner v. 
    Epps, supra
    , 439 Fed. Appx. 408;
    Allen v. Secretary, Florida Dept. of Correc
    tions, supra
    ,
    
    611 F.3d 764
    –65; Cummings v. Secretary for the Dept.
    of Correc
    tions, supra
    , 
    588 F.3d 1358
    –59; Chandler v.
    
    Greene, supra
    , 
    1998 WL 279344
    , *8; Snell v. 
    Lockhart, supra
    , 
    14 F.3d 1303
    .
    Accordingly, we agree with the United States Court
    of Appeals for the Eleventh Circuit that, if the record
    establishes that the petitioner made a knowing and
    intelligent decision not to present mitigating evidence
    under the general factors previously discussed, he must
    make two showings to establish prejudice under Strick-
    land. First, the petitioner must show that if he had been
    advised more fully about the mitigating evidence, there
    is a reasonable probability he would have permitted trial
    counsel to present such evidence at trial. See Gilreath v.
    Head, 
    234 F.3d 547
    , 551 (11th Cir. 2000), cert. denied,
    
    534 U.S. 913
    , 
    122 S. Ct. 255
    , 
    151 L. Ed. 2d 186
    (2001);
    see also Cummings v. Secretary for the Dept. of Correc-
    
    tions, supra
    , 
    588 F.3d 1360
    (‘‘there cannot be a reason-
    able probability of a different result if the defendant
    would have refused to permit the introduction of miti-
    gating evidence in any event’’). Second, the petitioner
    must establish that, if such evidence had been pre-
    sented, a reasonable probability exists that the result
    would have been different. Cummings v. Secretary for
    the Dept. of Correc
    tions, supra
    , 1365–66. With these
    standards in mind, we turn to the petitioner’s claims.
    1
    Failure to Discover Transcripts to Establish PTSD
    The petitioner claims that he was prejudiced by
    defense counsel’s failure to discover the 1966 tran-
    scripts because they deprived him of evidence that
    would have led to a diagnosis that he was under an
    extreme emotional disturbance caused by PTSD at the
    time of the crimes. According to the petitioner, the
    transcripts revealed that he was in a dissociative state
    when he killed his father, which would have led to a
    diagnosis that he suffered from PTSD with dissociative
    features when he killed his former wife and his son.
    The petitioner argues that such a diagnosis would have
    presented a different basis for an extreme emotional
    disturbance defense than the severe mixed personality
    disorder diagnosed by the criminal trial experts, which
    effectively portrayed him as a pathologically jealous
    former husband, as it would explain his violent reaction
    to stressful circumstances. We conclude that, even if
    we were to assume that guilt phase counsel were defi-
    cient for failing to discover the transcripts, any such
    deficiency did not prejudice the petitioner.
    Although the habeas court emphasized the fact that
    the petitioner would not agree to testify in support of
    an extreme emotional disturbance defense and might
    even insist on testifying to dispute that he had commit-
    ted the crimes, our conclusion rests on a broader view
    of the record consistent with our previous discussion
    of the law.13 The record provides ample proof that the
    petitioner had consistently and unequivocally taken the
    position that he would not allow counsel to present
    any mitigating evidence that was tantamount to an
    admission that he had committed the crimes, but lacked
    the intent to kill when he did so. The sole statements
    to the contrary came shortly after his arrest, between
    January 11 and February 20, 1988. Don Light, a defense
    investigator, noted that when he questioned the peti-
    tioner about his sister’s report that he was having night-
    mares and flashbacks, the petitioner ‘‘became cheerful
    and made vague statements, such as, if I did it, I can’t
    believe that I did. He also said is it possible that I could
    have done this and not be aware that I did so.’’ Weeks
    later, the petitioner provided a detailed confession in
    his first interview with Borden, in the presence of Light
    and Kelly.
    From March, 1988 until the defense rested in April,
    1989, the petitioner, however, vehemently denied that
    account. When Borden met with the petitioner for the
    second time in March, 1988, two weeks after he had
    confessed to the crimes, the petitioner not only refused
    to discuss the events on the night of the murders but
    denied having committed the crimes. When Borden con-
    fronted him with his prior confession, the petitioner
    acknowledged the statement but said that he had made
    it up. He continued to maintain that he had not commit-
    ted the crimes in subsequent interviews with Borden
    in September and December, 1988. Similarly, Phillips
    noted that, in her October, 1988 psychological evalua-
    tion, the petitioner insisted that he had no direct knowl-
    edge of the manner of the victims’ deaths. In her report,
    Phillips further noted that, ‘‘[a]lthough he strongly
    denied knowledge of his family’s murder, [the peti-
    tioner] stated that ‘I told them I did it . . . they needed
    somebody . . . I had no reason not to tell them . . .
    I have no reason to go on anymore.’ ’’
    The petitioner also repeatedly expressed a desire to
    either force the state to prove its case or to have the
    state execute him. In September, 1988, Light reported
    to defense counsel that, when he had informed the
    petitioner about his upcoming evaluation with Phillips,
    the petitioner had said that defense counsel promised
    him the best possible defense, that he wanted a trial,
    and that he wanted ‘‘the state to ‘have to prove the
    case’ so that they can ‘zap me,’ which is ‘what I want.’ ’’
    In response to this news, Kelly wrote a letter to the
    petitioner stating that Light had reported the petition-
    er’s ‘‘expressed desire to have the [state] execute [him],
    and the effect of that attitude on the nature of any
    defense to be presented.’’ Kelly asked the petitioner to
    keep an open mind on his options until defense counsel
    had a chance to assess all of the information and present
    him with his options.
    At some unspecified point, the petitioner wrote a
    letter to Kelly stating in part: ‘‘I have no need of spending
    the rest of my life or any large part of it in a prison with
    unknown dreams, feelings and [an] uncertain knowing
    guilt. So my need is not to settle for anything lesser
    than the electric chair and without appeal which in turn
    will cause my death. For that’s the least I can do. I can’t
    feel or think of any other way!’’
    In her October, 1988 psychological evaluation, Phil-
    lips noted that the petitioner had said that ‘‘ ‘it’s not
    worth trying to restart a life.’ ’’ The petitioner
    ‘‘expressed skepticism about his attorneys, doubting
    their commitment to helping him. He described the legal
    proceedings as a ‘game’ and stated that he was now
    only interested in seeing how ‘the system is—how good
    or bad it is—how the game is played.’ ’’
    Sometime between the end of December, 1988 and
    the beginning of January, 1989, the petitioner rejected
    a plea bargain under which he would have avoided a
    death sentence but would have had to spend the rest
    of his life in prison. In a January, 1989 letter to the
    petitioner, defense counsel memorialized the two alter-
    natives that the petitioner had rejected, one of which
    would have allowed him to enter an Alford plea14 of
    guilty to two counts of murder. To ensure that the
    petitioner understood what this meant, the letter
    explained that an Alford plea would simply acknowl-
    edge that the state had sufficient evidence that, if
    believed by a jury, would likely establish his guilt, and
    would not be an admission that the petitioner had com-
    mitted the crimes. The letter noted that counsel thought
    it was important to make this clear ‘‘[i]n light of the
    different positions you have taken with us at various
    times throughout the course of our representation (‘I
    didn’t do it’/‘I did it’/‘Maybe I did it’/‘I don’t remem-
    ber’) . . . .’’
    In that letter, defense counsel also recounted prior
    discussions with the petitioner regarding the fact that
    Borden’s psychiatric evaluation gave them a potential
    extreme emotional disturbance defense. The letter
    explained that, if credited, extreme emotional distur-
    bance would be a complete defense to capital felony,
    and would reduce the two murder counts to manslaugh-
    ter in the first degree, which would likely result in
    maximum, consecutive sentences for a term of forty
    years imprisonment. It went on to note: ‘‘Despite the
    fact that an [extreme emotional disturbance] defense
    could, if successful, significantly reduce any penalty,
    you have forbidden us to use such a defense. We advised
    you before you made that decision that, in our opinion,
    defending the charges on an [extreme emotional distur-
    bance] theory was the best way to go. Given your posi-
    tion on [extreme emotional disturbance], we will
    proceed accordingly, not because we agree that it is
    the best way to go, but because you, as the client have
    the power to make that decision, even if we feel it is
    not in your best interests. You should be aware, how-
    ever, that we, therefore, will not file any Notice of Inten-
    tion to Rely (on any kind of mental defense) as we are
    required to by law . . . .’’ The letter ended by advising
    the petitioner to inform counsel immediately if they
    had misunderstood his position with regard to rejecting
    the plea bargain or an extreme emotional disturbance
    defense. There is no evidence that the petitioner there-
    after contacted counsel to indicate that they had misun-
    derstood his position.
    As noted in part I of this opinion, because of their
    concerns about the petitioner’s statements and his
    rejection of their advice, defense counsel requested a
    competency evaluation in January, 1989. The evaluation
    noted that the petitioner ‘‘reported [that] his attorneys
    have discussed with him the possible defenses avail-
    able. . . . He indicate[d] that he differs with his attor-
    neys in his assessment of the strength of the evidence
    against him. He reports he is presently determined to
    take his case to trial, believing that the prosecution
    will have great difficulty proving his guilt ‘beyond a
    reasonable doubt’ to a jury.’’ Following the clinical
    team’s report to the court, two separate colloquies
    ensued with the petitioner. At each, the trial court con-
    firmed with the petitioner that he had directed counsel
    not to present a defense of extreme emotional distur-
    bance or ‘‘any psychiatric testimony,’’ and that he under-
    stood that he was forgoing the possibility of a strategy
    that could avoid a death sentence and life impris-
    onment.
    At the habeas trial, McWhirter testified that the peti-
    tioner had been adamant about not presenting evidence
    of extreme emotional disturbance at the guilt phase.
    McWhirter affirmed that he had explained to the peti-
    tioner ‘‘the risk of pursuing the reasonable doubt
    defense instead of [extreme emotional disturbance] or
    other mental state defense.’’ McWhirter stated that, in
    light of the petitioner’s position, their defense strategy
    was ‘‘to make the state cross all the ‘T’s, dot all the ‘I’s,
    and prove the case beyond a reasonable doubt.’’
    With respect to specifically using PTSD as the basis
    for an extreme emotional disturbance defense,
    McWhirter stated that he was sure that they had consid-
    ered that condition, by that name or in another form.
    McWhirter had always assumed that the petitioner was
    in a dissociative state when he committed the murders.
    Although the petitioner was never specifically diag-
    nosed with PTSD, McWhirter knew that the petitioner
    had traumatic events in his background that he thought
    had impacted the petitioner’s mental state.
    Kelly could not recall discussing PTSD with the peti-
    tioner, but explained that they had not considered rely-
    ing on PTSD as an affirmative defense at the guilt phase
    ‘‘because as with [extreme emotional disturbance] we
    were faced with a certain dilemma and that dilemma
    was that [the petitioner], in effect, had indicated that
    if we tried to offer a defense that necessarily involved
    him having done the act of killing his family, that he
    would insist upon testifying and denying it. Thereby,
    in my view, making him not only a murderer, if the jury
    should so find, but someone capable of looking them
    in the face and being—and—and lying to them and
    being a liar on top of it, which then would have implica-
    tions for the penalty phase.’’
    This evidence conclusively demonstrates that the
    petitioner was informed, by the court and by counsel,
    that mitigation evidence could be presented that could
    reduce his culpability, and was advised against proceed-
    ing on a theory of reasonable doubt that had little
    chance of success. The court found the petitioner com-
    petent to make this decision, a finding that was sup-
    ported by the opinion of an independent panel. That
    his decision made it more likely that he would be
    exposed to a death sentence rather than a lengthy sen-
    tence of imprisonment does not in and of itself contra-
    vene that finding.15 The petitioner did not expressly
    limit or in any way qualify the scope of his decision to
    any particular extreme emotional disturbance theory or
    type of psychiatric testimony. Nor is there any evidence
    from which such a limitation may be inferred.
    From his second meeting with Borden in March, 1988
    until the defense rested at the guilt phase in April, 1989,
    the petitioner consistently refused to undertake any
    course of action that would be tantamount to an admis-
    sion to having committed the crimes and insisted on
    forcing the state to prove its case beyond a reasonable
    doubt. The petitioner effectively took the position that
    the only acceptable outcome would be an acquittal or
    a death sentence. In either case, an extreme emotional
    disturbance defense, whether based on PTSD or other
    mental conditions, would thwart that clear intention.
    The mere fact that defense counsel never specifically
    discussed PTSD by its name and diagnostic features
    with the petitioner does not support a conclusion that a
    reasonable possibility existed that the petitioner would
    have allowed counsel to advance a defense based on
    PTSD if counsel had informed him that there was evi-
    dence to support such a theory. Defense counsel’s
    investigation in support of an extreme emotional distur-
    bance defense uncovered many of the same basic facts
    essential to the habeas experts’ diagnosis of PTSD with
    dissociative features.16 The habeas experts opined that
    the petitioner’s PTSD arose from childhood trauma,
    events before and including his father’s death. Borden
    opined that the severe chronic abuse that the petitioner
    had suffered when he was a child was the cause of the
    petitioner’s mental disorder and had ‘‘led up to what
    happened.’’ He characterized the death of the petition-
    er’s father as an event that left a deep emotional scar
    and connected it to the 1987 killings. The habeas experts
    opined that methamphetamine intoxication would
    exacerbate PTSD symptoms of impulsivity and aggres-
    sion. Borden reached the same conclusion regarding
    the drug’s effects on the condition he had diagnosed,
    specifically stating that the drug could trigger violent
    behavior.17 Phillips testified that the petitioner’s illness
    would significantly reduce his ability to contain his
    emotions and rage if confronted with conflict or loss.
    The habeas experts opined that the 1966 event placed
    the petitioner at greater risk of responding to traumatic
    events by developing a dissociative reaction. Borden
    and Phillips described the petitioner’s mental condition
    as one that could cause a person, when under severe
    stress, to ‘‘dissociate,’’ experience ‘‘depersonalization,’’
    ‘‘derealization,’’ or a ‘‘disoriented state,’’ or go into a
    fugue state where one lacks awareness of what he is
    experiencing. Borden pointed specifically to the peti-
    tioner’s perception that he was not harming the victims
    but rather that his hand had committed the harmful
    acts. Defense counsel testified that they ‘‘always’’ had
    thought that the petitioner was in a dissociative state
    attributable to his childhood abuse at the time of the
    killings, even though they did not attribute it specifically
    to PTSD.
    Indeed, one of the petitioner’s habeas experts who
    diagnosed the petitioner with PTSD, Blumberg, testi-
    fied: ‘‘I think . . . Borden and I are in the same ballpark
    but may have some different diagnostic labels that we’re
    using. . . . If you think that what . . . Borden has dis-
    cussed in his diagnosis of this mixed personality disor-
    der, all these features that he labels are actually features
    and symptoms of [PTSD]. . . . I would just really
    describe many of these features that he sees as part of
    his personality disorder as really being diagnostic of
    chronic [PTSD].’’
    We do not intend to suggest that PTSD and severe
    mixed personality disorder with the petitioner’s associ-
    ated features lack any clinically material distinction.
    Nor do we suggest that defenses based on PTSD and
    such a disorder would have had equivalent tactical
    advantages. Our concern is whether these diagnoses
    would have been seen as materially different from the
    petitioner’s perspective when deciding to preclude an
    extreme emotional disturbance defense or the presenta-
    tion of any psychiatric testimony. The record does not
    establish that there is a reasonable probability the peti-
    tioner would have allowed counsel to present a PTSD
    defense if only counsel had discussed PTSD by name,
    clinical definition, or symptomology.
    To the extent that the petitioner argues that his deci-
    sion was based on an extreme emotional disturbance
    defense limited to a theory that the petitioner commit-
    ted the crimes because he was a sad, pathologically
    jealous man, the scope of the investigation and the
    testimony of Borden and Phillips does not support that
    limited view. It might be fair to say that the state pressed
    such a theory, but those characteristics were only one
    part of a far more complex picture of the petitioner’s
    mental condition that defense counsel’s investigation
    had yielded. Nothing in the record reflects that defense
    counsel ever discussed their proposed defense in such
    terms with the petitioner. The petitioner declined to
    testify on this or any other matter at the habeas trial.
    For the foregoing reasons, the petitioner cannot
    establish that he was prejudiced by counsel’s failure to
    uncover the 1966 transcripts. In light of his instructions
    to counsel and his refusal to assist in the development
    and presentation of mitigation evidence, there is not a
    reasonable probability of a different outcome if counsel
    had uncovered them. Moreover, because methamphet-
    amine intoxication was an essential element of the opin-
    ions of each of the petitioner’s experts, meaning that
    none concluded that PTSD alone caused an extreme
    emotional disturbance, the petitioner’s PTSD claim also
    fails for the reasons set forth in the next subpart of
    this opinion.
    2
    Failure to Test Blood Sample to
    Establish Methamphetamine
    (Desoxyn) Intoxication
    The petitioner claims that although the habeas court
    properly concluded that counsel was deficient for fail-
    ing to test the first blood sample because there was no
    strategic reason not to and such a test would have
    been the best evidence of intoxication, it improperly
    concluded that he was not prejudiced. He contends that
    the habeas court’s finding that he rejected a defense
    strategy based on intoxication is clearly erroneous. The
    petitioner further contends that he could not have made
    an informed decision to do so because counsel never
    discussed the presentation of intoxication evidence.
    We disagree.18
    The record reflects the following additional evidence
    related to the intoxication claim. In his February, 1988
    confession to Borden, in the presence of Kelly and Light,
    the petitioner recounted his alcohol and drug abuse in
    the years and months preceding the crimes, citing
    ‘‘drugs including [V]alium, [F]iorinal and [De]soxyn.’’
    In recounting the events in the days leading up to the
    murders early Sunday morning, December 13, 1987, the
    petitioner indicated that at various times on the preced-
    ing Wednesday and Thursday, he had been drinking and
    taking pills, including Desoxyn specifically, but could
    not remember how many pills. In his account of the
    events on Friday, Saturday, and early Sunday morning,
    he noted at several points that he had been drinking,
    but did not mention taking any pills or drugs.
    Notes dated February, 1988, reflect that Light began
    an investigation into the petitioner’s drug use in the
    days leading up to the crimes. He obtained a letter from
    the physician who had prescribed medications to the
    petitioner since 1985, which indicated that the physician
    had last prescribed Desoxyn to the petitioner on Decem-
    ber 9, 1987 (three full days before the crimes). Light
    interviewed the pharmacist who had filled that prescrip-
    tion as well as previous prescriptions. The pharmacist
    indicated that the petitioner had previously abused his
    prescription medication, trying to obtain refills prema-
    turely. The pharmacist confirmed that, on December 9,
    he had filled the petitioner’s prescriptions for thirty
    Desoxyn pills and for 100 Fiorinal pills. Light learned
    that Desoxyn is an amphetamine and Fiorinal is a relax-
    ant. Light found it ‘‘[n]otable’’ that, although the
    Desoxyn prescription specified a dosage of one pill per
    day, the petitioner’s sister had informed Light that the
    bottle was empty when she found it in the petitioner’s
    apartment five days after the prescription had been
    filled.19 Light also contacted the petitioner’s health
    insurance provider to ascertain when and for what pre-
    scriptions it had paid.
    At the habeas trial, McWhirter confirmed that the
    petitioner’s use of medications would have been a sub-
    ject of inquiry because such use could be relevant to
    the petitioner’s state of mind and a possible defense
    strategy. Light’s report of his investigation into the peti-
    tioner’s prescriptions and the empty prescription bottle
    gave McWhirter reason to believe that the petitioner
    may have been under the influence of more than his
    prescribed level of medication at the time of the mur-
    ders. McWhirter testified that the petitioner had told
    defense counsel ‘‘from the beginning that he was under
    the influence . . . of alcohol and prescription medica-
    tions . . . .’’ McWhirter further testified that, although
    he had no recollection of the specific inquiry to the
    petitioner whether he was using any drugs or alcohol
    at the time of the murders, he was ‘‘quite sure that we
    had such a discussion at some point.’’ He could not
    recall whether the petitioner had informed defense
    counsel of the quantity of each drug he had taken before
    the murders, but assumed the questions had been asked.
    As previously noted, McWhirter explained that the use
    of intoxication evidence ‘‘never got raised because [the
    petitioner] would not let us go in that direction.’’
    We conclude that the habeas court’s finding that the
    petitioner would not allow counsel to present intoxica-
    tion evidence is not clearly erroneous. The habeas court
    credited McWhirter’s testimony that intoxication had
    been discussed with the petitioner and that he would
    not allow them ‘‘to take this approach.’’ Insofar as this
    is a pure credibility determination, it is unassailable.
    See Sanchez v. Commissioner of Correction, 
    314 Conn. 585
    , 604, 
    103 A.3d 954
    (2014) (‘‘we must defer to the
    [trier of fact’s] assessment of the credibility of the wit-
    nesses based on its firsthand observation of their con-
    duct, demeanor and attitude’’ [internal quotation marks
    omitted]); Taylor v. Commissioner of Correction, 
    284 Conn. 433
    , 448, 
    936 A.2d 611
    (2007) (‘‘[t]he habeas judge,
    as the trier of facts, is the sole arbiter of the credibility of
    witnesses and the weight to be given to their testimony’’
    [internal quotation marks omitted]). Indeed, the peti-
    tioner offered no evidence to the contrary.
    Granted, this single statement alone would be a thin
    reed on which to rest the habeas court’s ultimate find-
    ing. The evidence previously discussed, however,
    makes clear that this statement was not the only support
    for this finding. The evidence established that counsel
    had recognized that intoxication evidence could be used
    to raise a question as to the petitioner’s ability to form
    the necessary specific intent, and had commenced an
    investigation into this subject. Defense counsel
    obtained information from the physician who pre-
    scribed medications to the petitioner, the pharmacist
    who filled the prescriptions, the insurance company
    who paid for the prescriptions, and a family member
    who had knowledge of the petitioner’s usage. From
    these sources and the petitioner’s confession, counsel
    learned what medications the petitioner actually had
    been prescribed shortly before the murders, that he
    previously had abused his medications, that he had been
    abusing them a few days before the murders, and that
    most of his thirty day supply of Desoxyn, received on
    December 9, was gone on December 14. The fact that
    no further investigation was undertaken would seem
    to corroborate that the petitioner had instructed coun-
    sel not to ‘‘go in that direction.’’ Indeed, such an instruc-
    tion was wholly consistent with the petitioner’s refusal
    to allow the presentation of any theory tantamount
    to an admission to committing the homicides, and his
    expressed desire to make the state prove its case.
    Despite the fact that the two colloquies with the crimi-
    nal trial court were limited to the petitioner’s decision
    not to present evidence of extreme emotional distur-
    bance, we are persuaded that the record establishes
    that the petitioner understood the consequences of
    refusing to allow evidence of intoxication. Indeed, the
    only strategies that he ever embraced prior to the con-
    clusion of the guilt phase were to obtain an acquittal
    or a sentence of death. A successful presentation of
    intoxication evidence would not achieve either end.
    Therefore, the petitioner’s instructions to counsel pre-
    clude his claim that he was prejudiced by counsel’s
    failure to test the blood sample because he has not
    established that he would have allowed evidence of
    intoxication had such a test been conducted.
    Even if the petitioner could successfully distinguish
    a defense strategy based on intoxication from one based
    on an extreme emotional disturbance, he still could not
    establish the prejudice necessary to prevail on a claim
    of ineffective assistance. We agree with the habeas
    court that the petitioner did not proffer evidence estab-
    lishing a reasonable probability that he ingested an
    intoxicating dose of Desoxyn at a point in time prior
    to the crimes when it would have materially affected
    his conduct during the commission of the crimes.
    Putting aside the habeas court’s questions as to
    whether the petitioner’s experts accurately extrapo-
    lated from the blood sample a range of the level of
    methamphetamine at the time of the blood draw, the
    petitioner’s expert, Stewart, conceded that these levels
    could be explained by the ingestion of Desoxyn shortly
    before the crimes, shortly after the crimes, or some
    combination thereof. He admitted that his intoxication
    opinion, therefore, relied upon an ‘‘assumption’’ that
    the petitioner had ingested the pills before the crimes,
    finding support for that assumption in the contrast
    between the petitioner’s description of his state of mind
    during the crimes and others’ description of his
    demeanor in the thirty-six hours afterward. According
    to Stewart, the petitioner’s description was consistent
    with someone suffering from methamphetamine intoxi-
    cation, whereas others’ descriptions were ‘‘consistent’’
    or ‘‘not inconsistent’’ with someone coming down from
    a methamphetamine high. Stewart admitted on cross-
    examination, however, that the petitioner’s demeanor
    after the crimes was not inconsistent with someone
    suffering methamphetamine intoxication, and that it
    was possible for someone to be in such a state without
    it being readily apparent. Stewart’s opinion did not
    account for the petitioner’s strategic conduct upon leav-
    ing the crime scene of washing away any traces of
    blood from his person, clothing, and shoes. Moreover,
    Stewart’s assumption that a single blood draw could
    reliably establish the petitioner’s intoxication at a set
    point in time was not only contradicted by the respon-
    dent’s toxicology expert, Charles McKay, but also by the
    petitioner’s toxicology expert, Gary Lage. Lage testified,
    consistent with McKay, that one could not tell from the
    level of methamphetamine in a single blood sample how
    much of the drug had been taken or when it was taken;
    one would need either the dosage or the time of inges-
    tion to determine the other element.
    The petitioner’s experts also apparently gave no
    weight to the petitioner’s own statements regarding his
    drug consumption, which would seem to be the best
    evidence of this fact and did not support a theory of
    methamphetamine intoxication. The petitioner’s narra-
    tive to Borden contained no fewer than eight references
    to taking Desoxyn, ‘‘pills,’’ or ‘‘drugs.’’ He specifically
    recounted taking Desoxyn or ‘‘pills’’ as well as drinking
    at certain times on Wednesday and Thursday before the
    murders early Sunday morning. Although he recounted
    drinking (and, notably, even when, how many and what
    kind of alcoholic drinks he had) on Friday, Saturday,
    and the early hours of Sunday just before the murders,
    he never mentioned taking any pills during this period.
    Approximately thirty-two hours after the murders,
    when the petitioner was asked about his current medi-
    cations at the emergency room for treatment of his
    cut hand, he mentioned Fiorinal but not Desoxyn. The
    petitioner’s report to hospital personnel undermines
    the petitioner’s argument that little weight should be
    assigned to his failure to mention taking Desoxyn in
    his account to Borden because no one specifically asked
    the petitioner whether he had taken any pills shortly
    before the crimes. When asked, he still failed to report
    recently taking Desoxyn. Therefore, the petitioner has
    not established that there is a reasonable probability
    that, had the blood sample been tested, a different result
    would have ensued.20
    3
    Presentation of Reasonable Doubt Defense to
    Exclusion of Extreme Emotional
    Disturbance Defense
    The petitioner argues that, because defense counsel
    recognized that a reasonable doubt defense had a mar-
    ginal chance of success, they rendered ineffective assis-
    tance by failing to present a meritorious extreme
    emotional disturbance defense. The petitioner contends
    that defense counsel could not accede to the petitioner’s
    direction not to assert an extreme emotional distur-
    bance defense both because the petitioner’s decision
    was uninformed and because it was a tactical decision
    for counsel to make. Parts III A 1 and 2 of this opinion
    dispose of the petitioner’s first argument. We also dis-
    agree with his second argument.
    Numerous courts have held that counsel has an ethi-
    cal obligation to comply with an informed defendant’s
    refusal to allow presentation of a mental disease or
    defect defense or mitigating evidence in the penalty
    phase of a capital case. See Frye v. Lee, 
    235 F.3d 897
    ,
    906 (4th Cir. 2000) (‘‘[I]n North Carolina—as in most
    jurisdictions—the client must be permitted by his law-
    yers to control his own defense, as long as he is fully
    informed in making his decisions. . . . Frye’s attor-
    neys took reasonable steps to comply with their profes-
    sional responsibilities in this regard. Frye’s decision not
    to allow his family to aid in mitigation was unchanged
    after repeated discussions where his lawyers explained
    their displeasure with his position, and the conse-
    quences thereof.’’ [Citations omitted; internal quotation
    marks omitted.]), cert. denied, 
    533 U.S. 960
    , 
    121 S. Ct. 2614
    , 
    150 L. Ed. 2d 769
    (2001); Dobbs v. Turpin, 
    142 F.3d 1383
    , 1388 (11th Cir. 1998) (‘‘the decision whether
    to use mitigating evidence is for the client’’); Adams v.
    
    Quarterman, supra
    , 324 Fed. Appx. 347 (‘‘although the
    decision whether to use [mitigation] evidence is for the
    client, the lawyer first must evaluate potential avenues
    and advise the client of those offering potential merit’’
    [internal quotation marks omitted]); Johnson v. State,
    
    117 Nev. 153
    , 162 and n.14, 
    17 P.3d 1008
    (2001) (‘‘[t]he
    majority of [s]tates honor a competent defendant’s
    choice to forgo a defense strategy that asserts, in any
    way, that he or she was not guilty of the crime charged
    by reason of insanity—even over defense counsel’s
    objections’’; [internal quotation marks omitted]; and
    collecting cases).
    The logic underlying these decisions extends to a
    client’s instruction to his attorney not to present an
    extreme emotional disturbance defense. See Petrovich
    v. Leonardo, 
    229 F.3d 384
    , 386–87 (2d Cir. 2000) (‘‘The
    decision to assert an affirmative defense [such as
    extreme emotional disturbance] is akin to other, funda-
    mental trial decisions, such as the decision to plead to
    a lesser charge or to assert a plea of insanity. . . . If
    that analogy is sound, a court must accept a defendant’s
    will in such matters.’’ [Citations omitted.]), cert. denied,
    
    532 U.S. 981
    , 
    121 S. Ct. 1623
    , 
    149 L. Ed. 2d 485
    (2001);
    cf. State v. Jones, 
    99 Wash. 2d 735
    , 743, 
    664 P.2d 1216
    (1983) (en banc) (‘‘The stigma of insanity may in some
    cases be more damaging. Finally, a defendant may have
    legitimate philosophical reasons for opposing entry of
    [a not guilty by reason of insanity] plea. He may view
    such a plea as a tacit admission of guilt which he does
    not wish to make.’’). To conclude otherwise could force
    a defendant to represent himself in order to control the
    defense that he wishes to present. See, e.g., Godinez
    v. Moran, 
    509 U.S. 389
    , 392, 
    113 S. Ct. 2680
    , 
    125 L. Ed. 2d
    321 (1993) (‘‘[The] respondent informed the court
    that he wished to discharge his attorneys and change
    his pleas to guilty. The reason for the request, according
    to [the] respondent, was to prevent the presentation
    of mitigating evidence at his sentencing.’’); Johnson v.
    
    State, supra
    , 
    117 Nev. 161
    (‘‘the record reflects that
    [the defendant] asserted his right to self-representation
    mainly because of the ‘conflict of interests’ arising out
    of his differences with his counsel over the insanity
    defense’’).
    We also flatly reject the petitioner’s contention that,
    even if defense counsel could not advance an extreme
    emotional disturbance argument, they still could (and
    should) have presented evidence supporting that the-
    ory. The only substantive evidence supporting such a
    theory would have been elicited, perforce, from the
    petitioner himself, who plainly was not willing to sup-
    port such an effort, or from one of the defense mental
    health professionals, whose testimony the petitioner
    advised the court he did not want. We fail to see how
    such an approach would be faithful to the petitioner’s
    emphatic instructions. The fact that an extreme emo-
    tional disturbance instruction may be given despite a
    defendant’s refusal to pursue such a defense is not to
    the contrary. See, e.g., State v. Asherman, 
    193 Conn. 695
    , 729–31, 
    478 A.2d 227
    (1984), cert. denied, 
    470 U.S. 1050
    , 
    105 S. Ct. 1749
    , 
    84 L. Ed. 2d 814
    (1985). This
    instruction inures at least equally to the state’s benefit
    so as not to require a jury to acquit a defendant if a
    reasonable doubt arises as to intent or some other ele-
    ment of the offense. See 
    id., 731–32. Accordingly,
    defense counsel’s reluctant acquiescence to the peti-
    tioner’s insistence on proceeding exclusively under a
    defense of reasonable doubt did not constitute ineffec-
    tive assistance of counsel.
    B
    Ineffective Assistance of Counsel in the
    Petition for a New Trial
    The petitioner claims the habeas court improperly
    concluded that he had no statutory or constitutional
    right to counsel in his petition for a new trial and thus
    no corresponding right to effective assistance. He con-
    tends that every federal circuit to address this issue
    has concluded that a posttrial, preappeal motion for a
    new trial is a critical stage of the criminal proceedings,
    to which the constitutional right to counsel attaches,
    and that his petition for a new trial is subject to this
    same treatment. We disagree.
    A predicate to the right to effective assistance of
    counsel is the right to counsel. See McMann v. Richard-
    son, 
    397 U.S. 759
    , 771 n.14, 
    90 S. Ct. 1441
    , 
    25 L. Ed. 2d 763
    (1970) (‘‘[i]t has long been recognized that the right
    to counsel is the right to the effective assistance of
    counsel’’). ‘‘The [s]ixth [a]mendment safeguards to an
    accused who faces incarceration the right to counsel
    at all critical stages of the criminal process.’’ Iowa v.
    
    Tovar, supra
    , 
    541 U.S. 80
    –81. As the respondent prop-
    erly points out, there are substantive differences
    between a motion for a new trial and a petition for a
    new trial under Connecticut law that explain why the
    former is a critical stage of the criminal process and
    the latter is not.
    A motion for a new trial is filed ‘‘within the technical
    confines of the docketed criminal case. No separate
    civil action [i]s brought. . . . [A] petition [for a new
    trial] is instituted by a writ and complaint served on
    the adverse party; although such an action is collateral
    to the action in which a new trial is sought, it is by
    its nature a distinct proceeding. The judgment on the
    petition terminates the suit which renders it final. On
    the contrary, a motion for a new trial is filed in a case
    then in progress or pending and is merely a gradation
    in that case leading to a final judgment. . . . [E]rrors
    which are claimed to have been committed in rendering
    the judgment on a petition for a new trial are not review-
    able on an appeal from the judgment rendered in the
    action in which a new trial is sought. . . . On the other
    hand, errors which are claimed in relation to a motion
    for a new trial may be assigned on the appeal from the
    judgment rendered in the case in which the motion is
    made.’’ (Citations omitted; emphasis added; footnote
    omitted.) State v. Asherman, 
    180 Conn. 141
    , 143–44,
    
    429 A.2d 810
    (1980); accord State v. Goodwin, 3 Conn.
    Cir. Ct. 386, 388, 
    215 A.2d 913
    , cert. denied, 
    153 Conn. 725
    , 
    213 A.2d 525
    (1965).
    For the preceding reasons, a motion for a new trial
    is a critical stage of the criminal proceedings, to which
    the right to counsel attaches, whereas a petition for a
    new trial is a distinct proceeding. The latter is related
    to and can affect the criminal judgment in the same
    way that a habeas proceeding may. There is no constitu-
    tional right to habeas counsel, however, only a statutory
    right. See Gipson v. Commissioner of Correction, 
    257 Conn. 632
    , 646 nn.19 and 20, 
    778 A.2d 121
    (2001). The
    statutory right to counsel has not been extended to
    petitions for a new trial. See General Statutes § 51-296
    (a). Therefore, the habeas court properly determined
    that the petitioner could not advance a claim of ineffec-
    tive assistance of counsel in his petition for a new trial.
    C
    Cumulative Error
    The petitioner contends that the habeas court
    improperly concluded that his claims that the cumula-
    tive prejudicial effect of counsel’s deficient perfor-
    mance either constituted ineffective assistance or a
    violation of due process were not cognizable under
    Connecticut law. He contends that cumulative error is
    a valid basis on which to grant relief under federal and
    Connecticut case law.
    It appears to be an open question whether such claims
    are cognizable under Connecticut law. Compare Hinds
    v. Commissioner of Correction, 
    321 Conn. 56
    , 95, 
    136 A.3d 596
    (2016) (‘‘even if we were to recognize the [due
    process] cumulative error doctrine as articulated in the
    federal courts and to deem it applicable to habeas pro-
    ceedings, the trial improprieties in the present case
    would not justify relief under that doctrine’’), with State
    v. Harris, 
    182 Conn. 220
    , 232, 
    438 A.2d 38
    (1980) (‘‘The
    final portion of the cumulative error argument concerns
    the ineffectiveness of the defendant’s trial counsel.
    Because this claim has an independent basis in the sixth
    amendment to the United States constitution, we review
    the defendant’s contentions in this respect both as com-
    bining with the first two categories of cumulative error
    resulting in the denial of a fair trial and on its own
    merits with respect to the defendant’s independent right
    to the effective assistance of counsel.’’). Nonetheless,
    we need not resolve this question in the present case.
    We have previously concluded that any purported defi-
    ciencies caused no prejudice to the petitioner in light
    of his refusal to aid in presenting mitigation evidence
    and his resolute instructions to his attorneys not to
    present any such evidence. In other words, there is no
    prejudice to aggregate.
    D
    Brady Violation for Failing to
    Disclose 1966 Transcripts
    Finally, the petitioner contends that the habeas court
    improperly concluded that the state did not suppress
    the 1966 transcripts in violation of Brady because
    defense counsel’s discovery requests did not seek these
    documents and the state’s open file policy was sufficient
    to discharge its Brady obligations. In light of our conclu-
    sions in part III A 1 of this opinion, the petitioner cannot
    prevail even if this contention is correct.
    ‘‘In order to prove a Brady violation, the defendant
    must show: (1) that the prosecution suppressed evi-
    dence after a request by the defense; (2) that the evi-
    dence was favorable to the defense; and (3) that the
    evidence was material.’’ (Internal quotation marks omit-
    ted.) State v. Smith, 
    313 Conn. 325
    , 348, 
    96 A.3d 1238
    (2014). ‘‘[T]he test for materiality under Brady and the
    test for prejudice under Strickland [for ineffective assis-
    tance of counsel] are the same . . . .’’ Lapointe v. Com-
    missioner of Correction, 
    316 Conn. 225
    , 266–67, 
    112 A.3d 1
    (2015). Because we have already concluded that
    the petitioner failed to establish prejudice under Strick-
    land in relation to these transcripts, he cannot establish
    that they are material under Brady.
    E
    Conclusion
    The habeas court properly concluded that the peti-
    tioner had not established a basis for relief on any of
    his claims challenging his judgment of conviction. In
    light of intervening changes in the law, the petitioner’s
    claims challenging the penalty phase and resulting sen-
    tence of death have been rendered moot. The petitioner
    is free to file a motion to correct an illegal sentence
    pursuant to Practice Book § 43-22.
    The appeal is dismissed with respect to the petition-
    er’s claims regarding the imposition of a sentence of
    death; the judgment is affirmed.
    In this opinion the other justices concurred.
    * This case was originally argued before a panel of this court consisting
    of Chief Justice Rogers and Justices Palmer, Zarella, Eveleigh, McDonald
    and Robinson. Thereafter, Justice Zarella retired from this court and did
    not participate in the consideration of the case.
    1
    The trial court, Heiman, J., rendered judgment with respect to the capital
    felony count only and not the lesser included murder counts in light of
    the double jeopardy clause of the fifth amendment to the United States
    constitution. See State v. Breton, 
    264 Conn. 327
    , 333, 
    824 A.2d 778
    , cert.
    denied, 
    540 U.S. 1055
    , 
    124 S. Ct. 819
    , 
    157 L. Ed. 2d 708
    (2003); State v.
    Breton, 
    235 Conn. 206
    , 215 n.8, 
    663 A.2d 1026
    (1995).
    2
    General Statutes (Rev. to 1987) § 53a-54a provides in relevant part: ‘‘(a)
    A person is guilty of murder when, with intent to cause the death of another
    person, he causes the death of such person . . . except that in any prosecu-
    tion under this subsection, it shall be an affirmative defense that the defen-
    dant committed the proscribed act or acts under the influence of extreme
    emotional disturbance for which there was a reasonable explanation or
    excuse, the reasonableness of which is to be determined from the viewpoint
    of a person in the defendant’s situation under the circumstances as the
    defendant believed them to be, provided nothing contained in this subsection
    shall constitute a defense to a prosecution for, or preclude a conviction of,
    manslaughter in the first degree or any other crime.
    ‘‘(b) Evidence that the defendant suffered from a mental disease, mental
    defect or other mental abnormality is admissible, in a prosecution under
    subsection (a), on the question of whether the defendant acted with intent
    to cause the death of another person. . . .’’
    3
    The petitioner’s account was remarkably similar to the narrative that
    the state had presented to the jury at the guilt phase, which it had constructed
    on the basis of physical evidence at the scene. See Breton 
    II, supra
    , 
    235 Conn. 212
    –14.
    4
    In Breton III, this court interpreted a statement Borden made to mean
    that the petitioner had said that he thought he had seen someone walking
    around ‘‘inside.’’ Breton I
    II, supra
    , 
    264 Conn. 346
    . No one expressly referred
    to inside, however, and it is clear from the totality of the evidence that
    the petitioner indicated that he thought he had seen someone outside the
    apartment. Borden initially testified that the petitioner had stated that while
    he was sitting in his truck, he thought he saw ‘‘someone walking around
    the house,’’ and later clarified that the petitioner had said that he had seen
    someone walking around outside. The latter is consistent with a contempora-
    neous report of the petitioner’s narrative to Borden, as well as the petitioner’s
    account of the events after he entered the apartment, which do not reflect
    any concern that a stranger might be present inside. In fact, a witness
    testified at the guilt phase that he was outside at the apartment complex
    at approximately 4:30 a.m. when he observed the petitioner leaving the
    apartment and thought that the petitioner had looked right at him.
    5
    The state suggested that this comment reflected the petitioner’s anger
    that neither his son nor his former wife had sent a card for the petitioner’s
    birthday, which was December 10, three days earlier.
    6
    The record does not make clear why the petition was withdrawn with
    prejudice.
    7
    The long gap between the criminal trial and the habeas trial stems from
    several factors. As a result of the petitioner’s three appeals to this court,
    and a petition for certification to appeal to the United States Supreme Court,
    the judgment in the petitioner’s criminal trial was not final until 2003. Then,
    several years lapsed due to a shared assumption by the parties that this
    habeas case would not go forward until the resolution of another habeas
    proceeding concluded in which the petitioner’s claim of unconstitutional
    racial disparities in the administration of the death penalty was consolidated
    with those of other petitioners raising that claim. Eventually, the present
    habeas action proceeded, after it became evident that the consolidated
    habeas action was not going to conclude in the near term. The latter was
    concluded in 2013. See In re Death Penalty Disparity Claims, Superior
    Court, judicial district of Tolland, Docket No. CV-05-4000632-S (October
    11, 2013).
    8
    ‘‘While intoxication is neither a defense nor an affirmative defense to a
    murder charge in Connecticut, evidence of a defendant’s intoxication is
    relevant to negate specific intent which is an essential element of the crime
    of murder.’’ State v. Stevenson, 
    198 Conn. 560
    , 568, 
    504 A.2d 1029
    (1986);
    see General Statutes § 53a-7 (‘‘[i]ntoxication shall not be a defense to a
    criminal charge, but in any prosecution for an offense evidence of intoxica-
    tion of the defendant may be offered by the defendant whenever it is relevant
    to negate an element of the crime charged’’).
    9
    Mark Rademacher filed the petition in 1999, but Norman Pattis and
    James Nugent assumed representation of the petitioner in 2002. Pattis and
    Nugent were claimed to have been ineffective.
    10
    The majority also concluded that the mitigating evidence at issue would
    not have changed the result. See Schriro v. 
    Landrigan, supra
    , 
    550 U.S. 481
    .
    11
    In cases in which there was only a challenge to counsel’s failure to
    present mitigating evidence, not to counsel’s failure to investigate such
    evidence, several state courts have required, as a matter of state law, that
    a waiver of the right to present mitigating evidence must be knowing, volun-
    tary, and intelligent. See State v. Hausner, 
    230 Ariz. 60
    , 84–86, 
    280 P.3d 604
    (2012) (en banc); Koon v. Dugger, 
    619 So. 2d 246
    , 248–50 (Fla. 1993); St.
    Clair v. Commonwealth, 
    140 S.W.3d 510
    , 560–61 (Ky. 2004); State v. Short,
    
    129 Ohio St. 3d 360
    , 368–69, 
    952 N.E.2d 1121
    (2011); State v. Johnson, 
    401 S.W.3d 1
    , 13 (Tenn.), cert. denied,          U.S.      , 
    134 S. Ct. 513
    , 187 L.
    Ed. 2d 371 (2013). At least one state court has treated this standard as
    constitutionally mandated, albeit prior to Schriro. See State v. Woods, 
    143 Wash. 2d 561
    , 609, 
    23 P.3d 1046
    (‘‘[l]ike other constitutional rights, a defendant
    may waive the right to present mitigating evidence so long as the waiver is
    made ‘knowingly, voluntarily, and intelligently’ ’’), cert. denied, 
    534 U.S. 964
    ,
    
    122 S. Ct. 374
    , 
    151 L. Ed. 2d 285
    (2001). Most of these state courts require
    a colloquy to ensure that this standard has been met. There is a split among
    these courts as to whether it is proper to inquire into the nature of the
    mitigating evidence that counsel had discussed with the defendant.
    12
    The Ninth Circuit appears to be alone in concluding that Schriro ‘‘is
    inapplicable where the defendant did not threaten to obstruct the presenta-
    tion of any mitigating evidence that counsel found,’’ and therefore does not
    apply when a defendant directs counsel not to present mitigation evidence.
    (Internal quotation marks omitted.) Stankewitz v. Wong, 
    698 F.3d 1163
    , 1170
    n.2 (9th Cir. 2012); see, e.g., Newland v. Hall, 
    527 F.3d 1162
    , 1205 (11th Cir.
    2008) (‘‘[w]hile [the] petitioner’s conduct in this case is not as extreme as
    the defendant’s conduct in Schriro, we follow the [c]ourt in drawing a
    distinction between a defendant’s passive [noncooperation] and his active
    instruction to counsel not to engage in certain conduct’’), cert. denied, 
    555 U.S. 1183
    , 
    129 S. Ct. 1336
    , 
    173 L. Ed. 2d 607
    (2009).
    13
    We agree with the petitioner that his refusal to admit to committing the
    crimes would not preclude the presentation of such a defense solely through
    expert testimony. We also agree with the petitioner that the risk that he
    might insist on testifying to disavow having committed the crimes would
    not preclude successfully establishing that defense. In fact, in Borden’s
    testimony at the first penalty phase hearing to establish mitigation, defense
    counsel elicited testimony on that very issue. Borden testified that, after
    their first meeting, the petitioner disavowed having committed the crimes
    and, when confronted with his earlier confession, the petitioner claimed
    that it was just ‘‘a story.’’ Borden discussed this retraction in a manner to
    bolster his diagnosis of severe mixed personality disorder.
    14
    North Carolina v. Alford, 
    400 U.S. 25
    , 37, 
    91 S. Ct. 160
    , 
    27 L. Ed. 2d 162
    (1970).
    15
    As the Eleventh Circuit explained: ‘‘[A] mentally competent, intelligent
    defendant, having been convicted of a brutal murder, faced life imprisonment
    or death. Insisting on doing things his way, he chose death and prevented
    his counsel from attempting to secure a life sentence through the develop-
    ment and presentation of mitigating circumstances evidence. That is not a
    choice that most people would have made, but it is one that he had the
    right to make, and he made it voluntarily and with full awareness of the
    consequences. . . . What [the defendant] does not have is the right to
    escape the consequences of his own decision not to present any mitigating
    circumstances evidence by shifting the blame for it to someone else.’’ (Cita-
    tion omitted.) Allen v. Secretary, Florida Dept. of Correc
    tions, supra
    , 
    611 F.3d 765
    .
    16
    We also note that when Phillips reviewed the 1966 transcripts in 2002,
    she thought that they were significant, but did not contradict previous
    findings. Rather, they provided stronger evidence in support of a conclusion
    that the petitioner was experiencing a dissociative episode when he killed
    his former wife and his son. Like Borden, she believed that further testing
    would be required to make additional diagnoses. The petitioner, however,
    would not meet with the criminal trial experts after December, 1988. No
    effort was made to have Phillips or Borden undertake such testing for
    the habeas trial. Rather, the petitioner’s habeas experts largely relied on
    information previously provided by the petitioner to Borden in February,
    1988, and supplemented that information with tests they administered to
    the petitioner more than twenty years after the criminal trial.
    17
    Blumberg drew a material distinction between PTSD and mixed person-
    ality disorder with respect to whether those conditions would be affected
    by methamphetamine intoxication. He opined that methamphetamine intoxi-
    cation would exacerbate PTSD but not mixed personality disorder.
    18
    Although we base our decision on Strickland’s prejudice prong, we note
    that our review of the record yielded evidence that calls into question
    whether the petitioner proved that counsel’s performance was deficient.
    The habeas court could not envision a tactical reason not to test the sample,
    but that conclusion necessarily presupposed that counsel knew or should
    have known about the effects of Desoxyn on a person with the petitioner’s
    mental condition when investigating the case prior to the 1989 guilt phase.
    Differences in Borden’s testimony at the two penalty phase hearings, how-
    ever, suggest that Desoxyn’s dangers, in general or in specific to someone
    with the petitioner’s mental disorders, were not generally known to the
    medical community in 1989. When Borden testified at the first penalty phase
    in 1989, he offered limited, innocuous testimony about Desoxyn, simply
    describing it as ‘‘a diet pill which gives you a high. [It] was one of the first
    antidepressants.’’ When Borden testified at the second penalty phase in
    1997, he characterized the drug’s effects as far more dangerous—a metham-
    phetamine with a potent stimulant effect, ten times more powerful than
    cocaine, the worst medication that could have been prescribed for someone
    with the petitioner’s mental illness, a drug that could trigger violent behavior,
    and a drug that when used in combination with alcohol would be like
    ‘‘throwing gasoline’’ on a ‘‘simmering fire.’’ When questioned about the differ-
    ences between his testimony, first by the state and then on redirect by the
    defense, Borden explained that the medical community’s knowledge about
    the deleterious effects of the drug had greatly evolved since 1989, so much
    so that the drug was no longer prescribed. An evolved state of knowledge
    would explain why the defense’s list of mitigating factors expressly included
    intoxication in the second penalty phase and not in the first penalty phase.
    In assessing whether the defense’s investigation was deficient, Strickland
    requires us to focus on counsel’s perspective at the time investigative deci-
    sions were made. See Rompilla v. 
    Beard, supra
    , 
    545 U.S. 381
    .
    We note that if neither Borden nor defense counsel knew about Desoxyn’s
    potential dangers, defense counsel’s discussions regarding the use of intoxi-
    cation evidence could have been directed at the petitioner’s use of other
    prescription medications as well as alcohol consumption. Borden also testi-
    fied at the second penalty phase that the effects of Fiorinal, a barbiturate,
    are dangerous for a disturbed person and its effects are amplified when
    mixed with alcohol. Nonetheless, because both parties implicitly assume
    that Borden, and, in turn, the defense, knew about Desoxyn’s dangers, our
    analysis similarly proceeds from such an assumption.
    19
    The petitioner’s sister testified at the second penalty phase that the
    thirty day supply was ‘‘almost all gone’’ when she found it. She was never
    asked to quantify that remark.
    20
    The petitioner’s reliance on Lapointe v. Commissioner of Correction,
    
    316 Conn. 225
    , 293–94, 
    112 A.3d 1
    (2015), for the proposition that he met
    his burden of proof because a jury reasonably could have credited his
    experts’ opinions and find a reasonable doubt as to his specific intent due
    to intoxication is misplaced. In Lapointe, we declined to defer to the habeas
    court’s finding that the opinions of the petitioner’s experts were not persua-
    sive because the habeas court’s criticism of those experts’ opinions was
    not premised on a credibility assessment, but instead on facts that were
    manifestly contradicted by the record. 
    Id., 276–89. In
    light of the lack of
    support for the habeas court’s finding, we scoured the record to determine
    whether it revealed any other apparent reason why a jury would be apt to
    discredit the testimony of the petitioner’s experts. 
    Id., 290. In
    the present
    case, the habeas court reasonably found that the petitioner’s experts had
    failed to establish a credible and adequate foundation for their intoxica-
    tion opinion.