In re Bacigalupo , 55 Cal. 4th 312 ( 2012 )


Menu:
  • Filed 8/27/12
    IN THE SUPREME COURT OF CALIFORNIA
    In re MIGUEL ANGEL BACIGALUPO       )
    )                      S079656
    on Habeas Corpus.        )
    ____________________________________)
    On petitioner‟s automatic appeal in this death penalty case, we affirmed the
    judgment. Thereafter, petitioner filed a habeas corpus petition. We ordered an
    evidentiary hearing on petitioner‟s claim that the prosecution had failed to disclose
    evidence that would have supported a case in mitigation at the penalty phase that
    petitioner committed the two murders because of a Colombian drug cartel‟s death
    threats against him and his family. After hearing the testimony of 17 witnesses,
    the referee found merit to petitioner‟s claim. We uphold that determination by the
    referee, and we grant petitioner‟s habeas corpus petition for relief from the
    judgment of death.
    I. PROCEDURAL BACKGROUND
    In April 1987, a jury found petitioner Miguel Angel Bacigalupo guilty of
    the December 29, 1983, murders of brothers Orestes and Jose Luis Guerrero.
    (Pen. Code, § 187; further undesignated statutory references are to the Penal
    Code.) The jury also found to be true special circumstance allegations of multiple
    murder (§ 190.2, subd. (a)(3)) committed during a robbery (former § 190.2, subd.
    1
    (a)(17)(i)).1 The jury returned a verdict of death. In June 1987, the trial court
    sentenced defendant to death. Four years later, this court affirmed the judgment in
    its entirety. (People v. Bacigalupo (1991) 
    1 Cal.4th 103
    .)
    Thereafter, the United States Supreme Court, ruling on petitioner‟s
    certiorari petition challenging our decision, vacated our judgment and remanded
    the matter to our court for reconsideration (Bacigalupo v. California (1992) 
    506 U.S. 802
    ) in light of the then recent decision in Stringer v. Black (1992) 
    503 U.S. 222
    . In Stringer, the high court set aside a Mississippi death judgment because the
    jury had considered an unconstitutionally vague aggravating factor in its penalty
    decision. (Id. at p. 237.) After the parties‟ briefing and after oral argument on
    whether the Stringer analysis applied in this case, we again affirmed the judgment.
    (People v. Bacigalupo (1993) 
    6 Cal.4th 457
    , 475.) We concluded that because of
    differences between the California and the Mississippi death penalty schemes,
    Stringer did not apply to this California case. (Ibid.) The high court then denied
    the petition for certiorari. (Bacigalupo v. California (1994) 
    512 U.S. 1253
    .)
    Petitioner‟s first habeas corpus petition, filed in May 1993, was denied by
    us in May 1994, based on the merits as well as untimeliness. This, his second
    petition, was filed in June 1999. In March 2001, we ordered the California State
    Department of Corrections (which has custody of prisoners sentenced to death) to
    show cause why petitioner was not entitled to relief from the judgment of death
    (our order did not pertain to either of the two murder convictions or the special
    circumstance findings) in light of petitioner‟s claim that the prosecution before
    trial failed to disclose evidence that at the penalty phase would have supported
    1      The robbery-murder special circumstance has been renumbered as section
    190.2, subd. (a)(17)(A).
    2
    petitioner‟s claim of having killed under duress. (See § 190.3, factor (g) [allowing
    evidence regarding “[w]hether or not defendant acted under extreme duress or
    under the substantial domination of another person”].) After the parties‟ briefing
    of that question, this court in November 2003 ordered an evidentiary hearing
    before a referee.
    Initially, because petitioner‟s trial occurred in Santa Clara County, we
    referred the matter to the presiding judge of that county‟s superior court for
    selection of a referee. Petitioner, however, sought to have all of the judges of the
    Santa Clara County Superior Court disqualified because Judge Joyce Allegro of
    that court had been the prosecutor in petitioner‟s capital trial. We then vacated our
    initial order and reassigned the matter to the Contra Costa County Superior
    Court‟s presiding judge, who proposed as referee retired Judge Richard Arnason.
    In March 2004, we appointed Judge Arnason as referee, directing him to supervise
    discovery, take evidence, and make findings on specified questions. Particularly
    relevant here is whether the prosecution failed to disclose information it obtained
    from a confidential informant (Gale Kesselman) who on September 6, 1985,
    testified at a pretrial ex parte hearing in this case held on the defense request to
    disclose the informant‟s identity.
    At the reference proceeding, which began in 2004 and had several hearings
    over a three-year period, 17 witnesses were called (the proceedings comprise some
    3,700 transcript pages). Based on the evidence presented, the referee in June 2009
    issued his report, which is before us. The referee found that the prosecution knew
    from its confidential informant, Gale Kesselman, that her former boyfriend, Jose
    Angarita (a Colombian native, who was a major drug dealer in San Jose,
    California, and knew the murder victims) had made statements implicating himself
    in ordering the killings. The referee further found that more than a year before
    Kesselman‟s testimony at the September 1985 pretrial ex parte hearing, she had
    3
    told the prosecution about a meeting between Angarita and petitioner on the night
    before the murders. These pieces of information from Kesselman, the referee
    found, were not turned over to the defense by the prosecution and would have lent
    support to a penalty phase case in mitigation that petitioner killed the two
    Guerrero brothers while under Colombian Mafia death threats against him and his
    family.
    The Attorney General filed objections to the referee‟s findings, and
    petitioner filed a response to those objections. After reviewing those filings, the
    referee‟s report, and the record of the reference hearing, as well as the
    documentary evidence filed in connection with the habeas corpus petition, and the
    appellate record in petitioner‟s capital case, we conclude that the withheld
    evidence was both favorable and material (Brady v. Maryland (1963) 
    373 U.S. 83
    ,
    87) on the issue of penalty, thus entitling petitioner to relief from the judgment of
    death.
    II. 1987 TRIAL EVIDENCE
    We summarize the evidence presented in petitioner‟s April 1987 capital
    trial that is of relevance here.
    In the afternoon of December 29, 1983, petitioner, who had recently come
    from New York, began working in a San Jose, California, jewelry store owned by
    Orestes Guerrero, a Peruvian immigrant. The job had been arranged by
    petitioner‟s mother, a Peruvian native who knew Orestes through the Peruvian
    community in the San Francisco Bay area. Present in the jewelry store on
    December 29 were owner Orestes Guerrero, his brother Jose Luis Guerrero, a
    Peruvian immigrant named Carlos Valdiviezo, and petitioner. Later that day,
    petitioner ordered Valdiviezo at gunpoint to lie down. Instead, Valdiviezo ran and
    hid in the store‟s bathroom; he came out only after hearing someone leave the
    4
    store through the front door. Valdiviezo then discovered the dead bodies of
    Orestes and Jose Luis Guerrero; both had been shot. That evening, police arrested
    petitioner at the Palo Alto home of his mother and stepfather, just as the stepfather
    was preparing to take petitioner to the airport. Found in petitioner‟s suitcases was
    jewelry taken from Orestes‟s store.
    Petitioner waived his constitutional rights under Miranda v. Arizona (1966)
    
    384 U.S. 436
    , and agreed to talk to the arresting officers about the murders.
    Initially, petitioner denied any involvement in the killings, claiming he had spent
    the entire day alone at his mother and stepfather‟s house. He blamed the crimes
    on an acquaintance, Karlos Tijiboy, saying that Tijiboy looked “a lot like”
    petitioner and that Tijiboy was “connected with the Mafia.”
    Later, however, petitioner admitted killing the two Guerrero brothers,
    claiming he had been ordered to do so two weeks earlier by the Colombian Mafia
    under threats to kill petitioner and his family, and that it was Tijiboy who had
    given him the order. The tape recording of petitioner‟s interview with the police
    was introduced into evidence by the prosecution at the guilt phase of petitioner‟s
    capital trial. Tijiboy, called as a witness for the prosecution, identified petitioner,
    but denied ordering petitioner to kill the Guerrero brothers.
    In closing arguments to the jury at the guilt phase of the trial, the
    prosecution made this statement: “Now Mr. Aaron [defense counsel] is going to
    have to find something to talk about. What will it be? Perhaps he will argue that
    there was a Peruvian [sic: Colombian] Mafia that ordered the defendant to rob and
    kill Jose Luis and Orestes Guerrero. But there is absolutely no evidence of that.”
    The prosecutor added: “The evidence is very clear . . . defendant didn‟t receive
    any instructions from anyone about robbing and killing the Guerreros. Only his
    greed sent him there.” The prosecution reiterated that point at the close of the
    penalty phase of the trial, when it told the jury the defense had offered no
    5
    mitigating evidence that petitioner had “acted under extreme duress or under the
    substantial domination of another person.” (§ 190.3, factor (g).) The prosecutor
    stressed at the penalty phase: “The defendant acted alone. In spite of the fact that
    he tried to blame others for his conduct, there is no evidence of that. The only
    duress was his greed. The only domination was his total indifference to human
    life.”
    III. FACTS LEADING TO THE 2004 POSTTRIAL EVIDENTIARY HEARING
    A. Pretrial (September 1985) Ex Parte Hearing
    In August 1985, while petitioner was still awaiting trial for the two
    murders, his counsel asked the trial court to order the prosecution to disclose the
    name and whereabouts of a confidential informant who was known to the
    prosecution and who, according to the defense, was a material witness on the issue
    of petitioner‟s guilt of the killings. Attached to the written request was a
    “Supplementary Offense Report” prepared on May 4, 1984, by San Jose Police
    Department Sergeant John Kracht and obtained by the defense through discovery.
    The report stated that Kracht was at a meeting held on April 18, 1984, at the Santa
    Clara County District Attorney‟s Office, where prosecution investigators Sandra
    Williams and Ron McCurdy “provided a confidential informant for purpose of an
    interview,” which was tape-recorded.
    Sergeant Kracht‟s May 1984 report stated: “The informant, relaying
    statements Jose Angarita made after the murders, suggested that revenge and not
    robbery was the motive and that the incident that was revenged happened some
    years ago.” The report also mentioned that in April 1984 Sergeant Kracht had
    interviewed Attorney Joseph DiLeonardo, who once represented Angarita. The
    police contacted DiLeonardo, Kracht‟s report explained, “because of statements
    attributed to him describing the murders of the Guerrero brothers as a contract
    6
    killing.” At the interview, which was tape-recorded, DiLeonardo denied
    describing the murders as contract killings. According to DiLeonardo, the
    mention of contract killings came from Santa Clara Police Department Sergeant
    Tom Hensley, who was preparing a case against one Ronnie Nance, who was then
    in the Santa Clara County Jail charged with the attempted armed robbery of a drug
    trafficker.
    In opposing the August 1985 defense motion for disclosure of the
    confidential informant‟s identity, the prosecution asserted its evidentiary privilege
    not to reveal that identity, arguing that here the public interest in nondisclosure
    outweighed the necessity for disclosure. (Evid. Code, § 1041, subd. (a)(2).) A
    hearing on that issue (Evid. Code, § 1042, subd. (d)) was then held on September
    6, 1985, in the chambers of Santa Clara County Superior Court Judge Read
    Ambler. At that hearing, at which the defense was not present, the judge heard the
    testimony of two witnesses: Sandra Williams and the confidential informant (Gale
    Kesselman). Judge Ambler also listened to the April 1984 tape recording of the
    police interview of the confidential informant. (The contents of this tape
    recording are described on pp. 11-12, post.)
    On September 24, 1985, Judge Ambler denied the defense motion for
    disclosure of the confidential informant‟s identity, issuing this order: “The Court has
    conducted an in camera hearing pursuant to Evidence Code Section 1042(d), the
    People having claimed the privilege set forth in Evidence Code Section 1041
    [protecting the identity of a confidential informant]. Based on the evidence presented,
    including the tape recording in question, the Court concludes that the informant is not
    a material witness on the issue of guilt and that there is no reasonable possibility that
    non-disclosure of the identity of the informant might deprive the defendant of a fair
    trial. The Court further finds that revealing any portion of the tape would tend to
    disclose the identity of the informant.” The order further stated: “The transcript of all
    7
    proceedings held in camera, and the tape introduced into evidence, are ordered sealed,
    and only a court may have access to same.”2 Thereafter, the prosecution never
    disclosed to the defense the identity of the confidential informant.
    Petitioner later raised issues pertaining to the confidential informant in his
    second habeas corpus petition, which is now before us.
    B. Second Petition for Writ of Habeas Corpus
    Pertinent here is claim G raised in petitioner‟s second habeas corpus
    petition and later presented at the evidentiary hearing we ordered on this issue.
    Claim G asserts that the prosecution withheld evidence that would have lent
    support to a case in mitigation at the penalty phase of petitioner‟s capital trial that
    petitioner killed the victims because of Colombian Mafia death threats against him
    and his family. Central to this claim is the testimony presented at the pretrial
    September 1985 ex parte hearing pertaining to the defense request for disclosure
    of the identity of the confidential informant.
    1. Testimony at the September 1985 ex parte hearing
    At the September 1985 ex parte pretrial hearing in the chambers of Judge
    Read Ambler, the prosecution called two witnesses: Sandra Williams, an
    investigator for the Santa Clara County District Attorney‟s Office, and Gale
    Kesselman, the confidential informant, each of whom testified out of the presence
    of the other witness.
    Williams testified that while investigating petitioner‟s murder case, she
    learned about confidential informant Kesselman through Ronnie Nance, who was
    2      In November 2003, when this court ordered the posttrial evidentiary
    hearing, we also sent petitioner‟s habeas corpus counsel a copy of the transcript of
    the September 1985 pretrial ex parte hearing. That transcript was later admitted
    into evidence at the evidentiary hearing.
    8
    then in the Santa Clara County Jail awaiting trial on charges of attempted murder
    and robbery. Nance said that Kesselman told him that her former boyfriend, Jose
    Angarita (a Colombian native and a major drug dealer in San Jose, California),
    had information about the two murders with which petitioner had been charged.
    Williams was able to find both Kesselman and Angarita, and she talked to them
    separately. Kesselman denied telling Nance that Angarita had any involvement in
    the killings of the two Guerrero brothers. Kesselman told investigator Williams
    that Angarita “was moving a lot of cocaine through Colombia into Florida,” and
    ultimately California, and that he knew murder victim Orestes Guerrero who had
    rented a small space in the back of Angarita‟s jewelry store in San Jose.
    Williams further testified at the September 1985 pretrial hearing that
    Kesselman had given federal agents information that led to a federal drug
    prosecution against several defendants charged with narcotics violations. In that
    federal case, Kesselman was a confidential informant and was “being protected.”
    Williams then explained that before becoming an investigator in the district
    attorney‟s office, she had been a “special agent” for the California Department of
    Justice, where she spent two years in an undercover capacity. She expressed the
    view that in the capital case against petitioner, the disclosure of Kesselman‟s
    identity would endanger Kesselman‟s life. Williams then left the ex parte hearing
    in Judge Ambler‟s chambers, and the prosecution called Kesselman as a witness.
    Kesselman testified that former boyfriend, Jose Angarita, had been
    distraught over the death of his friend, Orestes Guerrero, and that he had
    speculated that “it really wasn‟t just a robbery.” Angarita told Kesselman that he
    learned about the details of the murder scene from his jewelry business partner,
    Dan Burke.
    The prosecutor then asked Kesselman whether Angarita ever indicated that
    he knew petitioner, who was charged with killing the two Guerrero brothers.
    9
    Kesselman replied, “He didn‟t say one way or the other.” The bodies of the two
    Guerrero brothers were in different rooms, Kesselman said, “So [Angarita] was
    wondering how, you know, if [the killer] was just some robber, how did that
    robber manage to kill both people within such a short amount of time, without,
    you know, being heard and escaping. So that‟s why [Angarita] was speculating,
    well, maybe it could have been—maybe it was a revenge killing. Maybe it was a
    contract killing . . . . He was only speculating. He was wondering why someone,
    you know, if only the robber could be that fast or maybe there were two people.
    That‟s another speculation he used. Maybe there were two people.”
    According to Kesselman, Angarita was drawing upon his experience as a
    mercenary in Colombia and his knowledge of firearms when he speculated that the
    killer “had to be very fast or fairly well trained” or there must have been “two
    people.” In response to questions by the prosecutor, Kesselman said that Angarita
    made no mention of having information that the murders were either revenge
    killings or contract killings. The prosecutor then asked whether Kesselman had
    formed any opinion “as to the reason for the killings based on [her] conversations
    with Jose Angarita,” to which Kesselman replied, “No.” After concluding her
    testimony, Kesselman left the pretrial ex parte hearing, and prosecution
    investigator Williams was re-called to testify.
    The prosecutor asked Williams whether Kesselman had said that Angarita
    was the source of the information she had given to Williams. Williams replied:
    “She doesn‟t know anyone else in this case.” Williams further stated that a
    reference to Angarita was contained in Sergeant Kracht‟s May 1984
    “Supplemental Offense Report,” which had been turned over to the defense.
    At the end of the September 1985 pretrial ex parte hearing, Judge Ambler
    said that before ruling on the defense request for disclosure of the confidential
    10
    informant‟s identity, he wanted to listen to the tape recording of Sergeant Kracht‟s
    April 1984 interview of confidential informant Kesselman.
    2. Sergeant Kracht’s tape-recorded interview of
    confidential informant Gale Kesselman
    In a tape-recorded interview with Sergeant Kracht in April 1984 (three
    years before petitioner‟s capital trial), Kesselman described what former boyfriend
    Angarita had told her about the killings of the two Guerrero brothers. According
    to Kesselman, Angarita had been “real excited” when he told her that two of his
    friends had been killed. He said: “They say it was a robbery. But I know it
    wasn‟t.” When Kesselman asked the reason for the killings, Angarita replied that
    it was “an organized murder” because of “something that happened years ago.”
    He added that “one of the people was not supposed to die,” wondering aloud why
    the “other guy” had to be there. Angarita had described the murders as
    “professional” based on the positions of the bodies, each in a different room. He
    said that the guy who “was picked up” in connection with the murders was “gonna
    take the . . . fall,” and that there was someone else involved, who was “already on
    [his] way back to New York.”
    In the tape-recorded interview, Sergeant Kracht asked Kesselman whether
    she knew of anything else that might suggest that Angarita “was involved or not”
    in the killings. Kesselman replied: “[W]hile I was talking to [prosecution
    investigator] Sandy [Williams] and seeing the picture of the guy that, that was
    arrested for the murders, I think it‟s the same man that I had driven Jose [Angarita]
    to [meet] in San Francisco.”
    Kesselman then described driving with Angarita to a hotel on Nob Hill in
    San Francisco to meet a man who, Angarita said was from New York and was a
    “big” Colombian “drug dealer.” At one point, Angarita told Kesselman to
    telephone the hotel for directions. Following the desk clerk‟s directions, they
    11
    arrived at a hotel that Kesselman thought might have been a Hyatt Regency hotel.
    Standing by the hotel‟s door was a man Kesselman described as being in his mid-
    to-late 30‟s, or possibly younger. The man got into the car, and Kesselman drove
    around while Angarita and the man had a brief conversation in Spanish, a
    language that Kesselman did not understand. Kesselman was “almost positive”
    that Angarita called the man “Miguel” (petitioner‟s name is Miguel).
    3. Additional evidence presented in support of the second habeas
    corpus petition
    Claim G in petitioner‟s second habeas corpus petition asserts that the
    prosecution, before petitioner‟s capital trial, had failed to disclose evidence that
    would have supported a case in mitigation at the penalty phase of petitioner‟s
    capital trial that he had killed the two Guerrero brothers while acting under
    duress — that is, under Colombian Mafia death threats against him and his family.
    In support of this claim, petitioner presented two declarations by Gale Kesselman,
    both dated August 7, 1997.
    Kesselman‟s first declaration said that she had testified in chambers in
    petitioner‟s capital case, and that she also testified in a federal drug prosecution.
    After the federal case ended in convictions, she declined an offer by the federal
    Drug Enforcement Agency to place her in its witness protection program, as she
    perceived no threat to her personal safety.
    Kesselman‟s second declaration described extensive cocaine smuggling and
    dealing activities of former boyfriend, Jose Angarita. The declaration then states:
    “One day, around late December 1983, Jose asked me . . . to drive with him
    to San Francisco to meet someone from New York who was going to work for
    him. I remember we were to meet this man around a hotel and we had some
    trouble finding the right hotel. When we arrived at the hotel, we picked up Miguel
    Bacigalupo [petitioner]. Miguel was very casually dressed and he looked nervous
    12
    and out of place. Jose got in the back seat of the car with Miguel . . . . Jose and
    Miguel conversed in Spanish, which I do not understand fully. Jose was obviously
    discussing some kind of business arrangement with Miguel. The next day or so, I
    heard that two Peruvians[,] Orestes and Jose Guerrero, were killed in their jewelry
    shop on The Alameda, in San Jose. From that day on, Jose [Angarita] started
    acting very strangely. He was very nervous, and literally sweating when he
    watched the reports of the murders on television.”
    Kesselman‟s second declaration added that the two murdered Guerrero
    brothers had previously worked in Angarita‟s jewelry shop, and that Angarita told
    her he had “an obligation to set them up in a store,” which he considered “a
    burden.” The declaration attributes to Angarita a statement suggesting that “if
    people crossed him that their whole family would be killed.” The declaration also
    stated that Kesselman herself “began to suspect that Jose [Angarita] had been
    ordered to kill the Guerrero brothers.”
    Kesselman‟s second declaration also described a meeting with prosecution
    investigator Sandra Williams, who questioned Kesselman about Angarita‟s
    possible involvement in the killings of the two Guerrero brothers. Kesselman told
    Williams about Angarita‟s drug-dealing activities, and Williams turned that
    information over to the federal Drug Enforcement Agency. Kesselman estimated
    that when she was dating Angarita in 1983, he “was probably making one million
    dollars a week” dealing drugs.
    Kesselman‟s second declaration further stated that she told prosecution
    investigator Williams “everything” set forth in the declaration. According to
    Kesselman, Williams told her before the September 1985 pretrial ex parte hearing
    “not to mention [at that hearing] the possibility that the Guerrero brothers‟
    murders were contract hits ordered by Jose [Angarita].”
    13
    4. Evidence in support of the Attorney General’s return to our
    March 2001 order to show cause
    After we issued an order to show cause (returnable before this court)
    directing the prosecution to show why petitioner should not be entitled to relief
    from the death judgment, the Attorney General filed a return. With the return was
    a declaration by prosecution investigator Sandra Williams, who denied that she
    ever told confidential informant Kesselman to withhold information or to testify
    falsely at the September 1985 pretrial ex parte hearing.
    The Attorney General also submitted transcripts of two habeas corpus-
    related interviews of Kesselman conducted in May 2001 by John Kracht, who at
    the time of petitioner‟s 1987 trial was a sergeant with the San Jose Police
    Department, but who in May 2001 was an investigator for the California
    Department of Justice. In those two interviews, Kracht showed Kesselman a copy
    of the second of the two declarations she had signed on August 7, 1997, in support
    of the second habeas corpus petition (at issue here). As noted Kesselman said in
    that declaration that prosecution investigator Williams had told her not to mention
    at the September 1985 pretrial ex parte hearing “the possibility that the Guerrero
    brothers‟ murders were contract hits ordered by Jose [Angarita].” When Kracht
    asked Kesselman to point out any inaccuracy in that declaration, she replied that
    Williams had not told her to withhold information at the ex parte hearing. Kracht
    also showed Kesselman a photographic lineup, which included a photograph of
    petitioner taken in 1984 (shortly after the murders of the Guerrero brothers) and
    photographs of five other Latino men in the same age range. Kracht then asked
    Kesselman if she could identify the man she and Angarita had met on December
    28, 1983 (the night before the murders), at the San Francisco hotel. After initially
    saying she was unsure, Kesselman ultimately picked out a photograph other than
    petitioner‟s.
    14
    5. Kesselman’s third declaration
    In support of the traverse that petitioner submitted in response to the
    Attorney General‟s return, petitioner included a third declaration by Kesselman
    that was signed on May 25, 2002, a year after the just-described tape-recorded
    interviews with Attorney General investigator Kracht. In that third declaration,
    Kesselman stated that “everything” mentioned in her two previous declarations
    signed on August 7, 1997 (in support of the habeas corpus petition) was “accurate
    and true.”
    IV. ORDER OF REFERENCE
    A. Questions for the Referee
    In November 2003 we issued an order of reference in connection with
    petitioner‟s second habeas corpus petition. The order directed the referee to resolve at
    an evidentiary hearing several factual issues arising from petitioner‟s claim G. That
    claim asserts that the prosecution before petitioner‟s 1987 capital trial failed to
    disclose evidence supportive of petitioner‟s statement to the police that he had killed
    the two Guerrero brothers because of the Colombian Mafia‟s death threats against him
    and his family. Such evidence, according to petitioner, would have enabled him to
    present a case in mitigation based on duress at the penalty phase of his capital trial.
    We consider our questions to the referee on pages 21-25, post, when we discuss them
    in connection with the referee‟s factual findings.
    B. Reference Hearing Testimony
    Below, we summarize the testimony relevant to claim G that petitioner
    presented at the posttrial evidentiary hearing ordered by this court in November
    2003.
    1. Confidential informant Gale Kesselman
    Petitioner‟s primary witness in support of the second petition for a writ of
    habeas corpus was Gale Kesselman, the confidential informant whose identity the
    15
    defense sought to obtain before petitioner‟s 1987 capital trial for the murders of
    the two Guerrero brothers. At the posttrial evidentiary hearing before the referee,
    Kesselman testified to the series of events leading to her involvement in this case.
    In 1983, Kesselman became romantically involved with Jose Angarita, a
    Colombian native living in San Jose, California. She described Angarita as a San
    Francisco Bay area cocaine dealer, who sold 20 to 40 kilograms of cocaine each
    week, netting “around a million dollars or so a week.” Angarita, according to
    Kesselman, operated certain seemingly “legitimate” businesses in the San Jose
    area, including a gold and silver exchange as well as jewelry stores. Kesselman
    met Angarita through a mutual friend, who put the two together because
    Kesselman was in financial trouble. The plan was for Kesselman to work for
    Angarita in his illegal drug business and to earn enough money to pay off her
    debts. Kesselman made “drops” of drugs and money for Angarita.
    Sometime in 1984, Kesselman became a witness in a federal prosecution
    against several defendants charged with trafficking in cocaine. (In that case,
    Angarita was not a defendant; the lead defendant was a “lieutenant” in Angarita‟s
    drug trade, and at the reference hearing was, for safety reasons, given the assumed
    name of simply “Joseph.”) Prosecution investigator Sandra Williams had
    introduced Kesselman to federal Drug Enforcement Agency Agent Rod Alvarez,
    and Williams told Kesselman to tell Alvarez what she knew about Angarita‟s drug
    dealings. Kesselman testified in chambers before a federal judge, describing what
    she knew about Angarita‟s drug dealings. By the time of Kesselman‟s testimony
    in federal court, Angarita had fled the San Jose area; Kesselman believed him to
    be dead.
    After the defendants in the federal case were convicted, federal agents gave
    Kesselman $5000 and offered to place her in their witness protection program, an
    offer she declined.
    16
    Kesselman mentioned an interview with prosecution investigator Sandra
    Williams in connection with the murders of the two Guerrero brothers. Kesselman
    said she told Williams “everything” she knew about Angarita‟s drug dealings,
    which according to Kesselman extended from San Francisco to Los Angeles to
    Miami, and she mentioned Angarita‟s association with the Medellin drug cartel in
    Colombia.
    Kesselman further testified at the evidentiary hearing that she had told
    prosecution investigator Williams that on the night before the Guerrero murders,
    she drove Angarita and his drug trade associate, Joseph (see ante, p. 16), to a hotel
    in San Francisco‟s Nob Hill area. Angarita said they would be meeting at the
    hotel a “new supplier” who was from New York City. Angarita planned to talk to
    the supplier for “just a few minutes.” (At the hearing, Kesselman identified
    petitioner as the person she had met in December 1983 outside the San Francisco
    hotel.)
    Kesselman then mentioned stopping the car in front of the hotel, where
    petitioner was waiting. Petitioner got into the car, and he and Angarita started
    talking in Spanish (which Kesselman could not understand), while Kesselman
    drove the car around the block a few times. After dropping petitioner off at the
    hotel, Kesselman drove the two male passengers back to San Jose.
    Kesselman said that just before testifying at the September 1985 pretrial ex
    parte hearing she had discussed the issues with prosecution investigator Williams.
    In that discussion, one thing that “kept coming up” was Angarita‟s statement to
    Kesselman that the murders of the two Guerrero brothers were murders “for hire.”
    Angarita had told Kesselman that he had “instrumented” [sic] the killings of the
    Guerrero brothers by meeting with petitioner and “directing him to San Jose to the
    jewelry store” owned by murder victim Orestes Guerrero. Kesselman stated at the
    17
    reference hearing that she mentioned this information to prosecution investigator
    Williams before the pretrial ex parte hearing.
    Kesselman also testified at the reference hearing that had she been called as
    a witness at petitioner‟s 1987 capital trial, she would have testified to the same
    information she had provided prosecution investigator Williams, namely,
    Angarita‟s statements incriminating himself in the murders of the Guerrero
    brothers as well as the fact that Angarita had met with petitioner the night before
    the murders.
    In cross-examining Kesselman at the reference hearing, the prosecutor
    asked whether in her tape-recorded interviews with Attorney General investigator
    John Kracht in May 2001 Kesselman had lied when she told Kracht, contrary to
    her declaration submitted in support of the habeas corpus petition, that prosecution
    investigator Sandra Williams had not told her to lie at the September 1985 pretrial
    ex parte hearing. Kesselman then explained at the reference hearing that when
    Kracht kept wanting to “go over this point again,” she just wanted to get it over
    with, so she told Kracht, “Yes, all that I said” in the previous declarations “was
    nothing but a lie.”
    2. Prosecution investigator Sandra Williams
    Sandra Williams testified at the posttrial evidentiary hearing that in 1984
    she was an investigator for the Santa Clara County District Attorney‟s office. She
    became the lead investigator in petitioner‟s capital case on January 9, 1984, some
    11 days after the murders of the two Guerrero brothers.
    On February 14, 1984, Sergeant Joe Brockman of the San Jose Police
    Department told Williams that Santa Clara County Jail inmate Ronnie Nance
    might have some information about the Guerrero murders. On February 17,
    Williams and Brockman interviewed Nance in the jail. Nance mentioned talking
    to Gale Kesselman, who indicated to him that someone possibly connected to the
    18
    murders owned a gold and silver exchange in Sunnyvale, California. According to
    Williams, she passed on to David Gonzales, an investigator with the Santa Clara
    County Public Defender‟s Office, “everything that Nance was saying.” On March
    6, 1984, Williams interviewed Scott Burke (the son of Dan Burke, Angarita‟s
    jewelry business partner), who mentioned Jose Angarita to Williams; this was the
    first time that Williams had heard that name.
    Williams then tracked down Gale Kesselman, who when first interviewed
    by Williams denied knowing anyone named “Miguel,” petitioner‟s first name.
    Kesselman insisted that Angarita could not have been involved in killing the two
    Guerrero brothers because they were his friends. Kesselman initially described
    Angarita as a “former boyfriend” whom she had “dated” for three months. Later,
    however, Kesselman said her romantic involvement with Angarita lasted only 30
    days. In describing at the reference hearing her conversations with Kesselman,
    Williams said: “Everything changed with her every time I talked to her.”
    Williams also testified that she had looked into Kesselman‟s claim that on
    December 28, 1983 (the night before the murders) Kesselman and Angarita
    stopped in front of a hotel on Nob Hill in San Francisco to pick up a man
    resembling petitioner. Williams contacted hotels in the Nob Hill area and found
    that for the night of December 28, 1983, none of the guest registers listed any
    person with a Spanish surname. Nor could Williams verify Kesselman‟s claim
    that Angarita was a major drug dealer.
    3. San Jose Police Sergeant John Kracht
    At the reference hearing, John Kracht testified that in April 1984, he was a
    sergeant in the San Jose Police Department assigned to the capital case against
    petitioner. While working on the case, Kracht made personal notes. According to
    Kracht, he would not at the time have given those personal notes to anyone in the
    district attorney‟s office. Those personal notes included this entry: “[Prosecution
    19
    investigators Ron McCurdy and Sandra Williams] indicated that they had
    tentatively associated [petitioner] with Angarita on the evening before the double
    murder and had been told by several persons that the homicides were a hit or
    carried out for financial gain at the direction of another. The other that they
    suspected was Jose Angarita.” Angarita‟s name, and a suggestion that robbery
    might not have been the motive for the Guerrero murders, did make it into the
    “Supplementary Offense Report” that Kracht prepared in May 1984 and that was
    provided to the defense sometime before August 1985 (when petitioner‟s counsel
    attached a copy to the request for disclosure of the confidential informant).
    Kracht testified that while working as an investigator for the state Attorney
    General‟s Office, he met with Kesselman on May 15 and again on May 17, 2001.
    He asked her to go over her two 1997 declarations, which supported the habeas
    corpus petition and were prepared by petitioner‟s habeas corpus counsel.
    Kesselman spontaneously pointed out errors in the declarations. Kracht denied
    pressuring Kesselman to disavow any statements in either of the declarations.
    4. Attorney John Aaron
    Also testifying at the reference hearing was John Aaron, who in 1987 was a
    deputy public defender in Santa Clara County and represented petitioner at trial;
    previously, petitioner‟s counsel had been Deputy Public Defender Michelle
    Forbes. Aaron stated that before trial he had no evidence to corroborate
    petitioner‟s claim to the police that he killed the two Guerrero brothers because of
    Colombian Mafia death threats against him and his family. Had he known of such
    evidence, Aaron said, he would have offered it at the trial‟s penalty phase as
    mitigating evidence that the killings were committed under duress.
    20
    C. Referee’s Factual Findings on the Questions in Our Order of
    Reference
    The referee‟s report, filed in this court in June 2009, comprises some 150
    pages, including 39 pages of factual findings in response to the questions we asked
    in our March 2004 order of reference. Those questions are set forth below,
    followed by pertinent summaries of the referee‟s answers.
    Our first question to the referee asked: “What information did the
    prosecution obtain before or during petitioner‟s capital trial regarding a possible
    connection between one Jose Luis Angarita and the murders of Orestes and Jose
    Luis Guerrero? What, if any, of this information was given to the defense?”
    The referee found that at the time of the capital trial proceedings against
    petitioner, the prosecution knew from a confidential informant (Gale Kesselman,
    the former girlfriend of Angarita‟s) of a statement made by Angarita to
    Kesselman, that, as phrased by the referee, “the murders were drug-related
    revenge killings or contract hits on behalf of a drug cartel arising out of a dispute
    about an old drug debt,” and that Angarita acknowledged having been an
    “instrument in the murders.” The referee also found that Kesselman had told the
    prosecution about a meeting in San Francisco between Jose Angarita and
    petitioner the night before the murders.
    In addition, the referee found that based on the personal notes of San Jose
    Police Sergeant John Kracht in 1984, three years before petitioner‟s capital trial,
    the prosecution had this information:
    “[Investigators] Williams and McCurdy gave a presentation [at the district
    attorney‟s office] associating Jose Angarita, a former employer of Orestes
    Guerrero, with cocaine trafficking. They indicated they had tentatively associated
    Miguel Padilla [petitioner] with Angarita on the evening before the double murder,
    21
    and had been told by several persons that the homicides were a „hit,‟ or carried out
    for financial gain at the direction of another. The other that they suspected was
    Jose Angarita.”
    The above mentioned information, the referee concluded, had not been
    disclosed to the defense, but the prosecution did provide the defense before trial
    with a copy of Sergeant Kracht‟s May 1984 “Supplementary Offense Report.”
    That report mentioned a “confidential informant” who said that “Jose Angarita”
    had suggested that the “motive” for the Guerrero murders was “revenge and not
    robbery.”
    Our second inquiry to the referee asked: “Did the confidential informant
    who testified at the ex parte hearing on September 6, 1985, tell a district attorney
    investigator or other member of law enforcement connected with this case that the
    informant had witnessed petitioner‟s meeting with Angarita and others a day or so
    before the murders? If so, did the prosecution convey this information to the
    defense?” Our question further asked: “If the confidential informant told a
    district attorney investigator or other member of law enforcement about a meeting
    between petitioner and Angarita, was this information reliable?”
    The referee found that the confidential informant (Gale Kesselman) had
    told prosecution investigator Sandra Williams that Kesselman was present at a
    meeting between petitioner and Jose Angarita in San Francisco the night before
    the murders of the two Guerrero brothers, that this information about the meeting
    was not disclosed to the defense, and that the information was reliable.
    Our third question asked the referee: “Did the prosecution from any source
    . . . obtain any information that it did not provide to the defense that would have
    supported petitioner‟s claim to the police that he had killed Orestes and Jose
    Guerrero acting under the Colombian Mafia‟s death threats to himself or his
    family?” The referee found that the prosecution knew from Gale Kesselman, the
    22
    confidential informant, about Angarita‟s extensive drug dealing activities, his
    statements incriminating himself in the killings, and his involvement with a
    Colombian drug cartel, but did not disclose this information to the defense. The
    referee also found that “the prosecution through Sandra Williams affirmatively
    told the defense that the information about any putative connection between the
    killings and a drug-related contract hit was not correct.”
    Our fourth question to the referee asked: “If the prosecution withheld from
    the defense information (a) about a possible connection between Jose Luis
    Angarita and the murders of Orestes and Jose Guerrero; or (b) about a meeting
    between petitioner, Angarita and others a day or so before the killings; or (c) that
    would have supported petitioner‟s claim to police that he killed the Guerrero
    brothers acting under death threats to him and his family, what penalty phase
    evidence not otherwise known or available to the defense at the time of trial would
    have come to light had the withheld information been disclosed?”
    The referee found that the prosecution had withheld from the defense
    information about a connection between Jose Angarita and the killings of the two
    Guerrero brothers and also about a meeting between Angarita and petitioner the
    night before the killings. Had the prosecution disclosed this information to the
    defense, the referee said, petitioner‟s trial counsel could have presented mitigating
    evidence at the penalty phase of petitioner‟s capital trial that “there was a bigger
    fish,” namely Jose Angarita, who had manipulated petitioner, a “frightened 21-
    year-old,” to commit the killings, and that Angarita was a major drug dealer with
    links to a Colombian drug cartel. Disclosure of this information, the referee
    concluded, would have supported petitioner‟s claim to the police that he
    committed the murders under death threats from the Colombian Mafia.
    Our fifth inquiry to the referee was: “Did a district attorney investigator or
    other member of law enforcement connected to this case instruct the confidential
    23
    informant to withhold information at the ex parte hearing held on September 6,
    1985? If so, what information, if any, did the confidential informant withhold at
    that ex parte hearing? Did the district attorney investigator testify truthfully at the
    September 6, 1985, ex parte hearing?”
    The referee found that shortly before the September 1985 pretrial ex parte
    hearing before Judge Ambler, prosecution investigator Sandra Williams told
    confidential informant Gale Kesselman “to withhold information . . . and not to
    testify to all relevant facts” at the September 1985 hearing, and to disavow, in the
    referee‟s words, “direct knowledge that [the killings] were contract killing[s].”
    The referee also found that “Jose Angarita had informed [Kesselman] that the
    killings were contract and/or revenge killings,” and that Kesselman passed this
    information on to prosecution investigator Williams. The referee concluded that at
    the 1985 pretrial ex parte hearing Kesselman had “lied” when she testified that
    Angarita had made no mention to her that the Guerrero murders were “revenge”
    killings, and that Sandra Williams had “convinced her that . . . all she knew was
    speculation.”
    The referee also found that at the September 1985 pretrial ex parte hearing
    Kesselman did not mention her presence at a meeting between Angarita and
    petitioner in San Francisco the night before the murders of the two Guerrero
    brothers. Nor did prosecution investigator Williams say anything on that subject
    in her testimony at the ex parte hearing even though, as the referee found,
    Williams knew from Kesselman that Kesselman had been present at a meeting
    between Angarita and petitioner on the night before the murders. The referee
    found that at the September 1985 pretrial ex parte hearing Williams “did not
    testify truthfully” when she said that Kesselman had “no information” about the
    murders, and when she answered “no” when asked if Kesselman had indicated “in
    24
    any way that Jose Angarita said he had heard from any source” that the Guerrero
    murders were revenge killings.
    Our sixth question asked the referee: “Is it likely that disclosure of the
    confidential informant‟s identity to the defense would have led to evidence not
    otherwise known or available to the defense at the time of trial that would have
    supported petitioner‟s claim to have acted under death threats from the Colombian
    Mafia?” The referee so found. In response to our further question, the referee
    determined that had the prosecution disclosed the confidential informant‟s identity
    to the defense, petitioner‟s trial counsel would have interviewed her and learned
    about Jose Angarita‟s extensive drug dealings, his connection to the Colombian
    Medellin drug cartel, and his meeting with petitioner in San Francisco the night
    before the Guerrero murders. This evidence, the referee concluded, would have
    lent support to petitioner‟s claim to the police that the Colombian Mafia had
    ordered him to kill the two Guerrero brothers, and that he had done so because of
    death threats against him and his family.
    Our seventh inquiry to the referee was: “At the time of trial, what
    information was known to the prosecution that would have supported a theory that
    petitioner was hired to commit the murders or that otherwise could have been used
    to impeach a penalty phase case in mitigation based on petitioner‟s having acted
    under duress?” The referee found that certain information given to the prosecution
    by confidential informant Gale Kesselman suggested that petitioner had been hired
    to kill the two Guerrero brothers.
    V. DISCUSSION
    A. Legal Principles
    A petition for a writ of habeas corpus is a collateral attack on a
    presumptively valid judgment. (In re Bolden (2009) 
    46 Cal.4th 216
    , 224; In re
    Clark (1993) 
    5 Cal.4th 750
    , 764.) Therefore, “ „the petitioner bears a heavy
    25
    burden initially to plead sufficient grounds for relief, and then later to prove
    them.‟ ” (In re Price (2011) 
    51 Cal.4th 547
    , 559.) When a petitioner states “a
    prima facie case for relief on one or more claims,” and this court issues an order to
    show cause, that order creates a “new cause” that is “limited to that specific claim
    or claims.” (People v. Superior Court (Pearson) (2010) 
    48 Cal.4th 564
    , 572.)
    Once this court issues an order to show cause, the petitioner‟s custodian
    “file[s] a responsive pleading, called a return, justifying the confinement.”
    (People v. Duvall (1995) 
    9 Cal.4th 464
    , 475.) In response to the return, the habeas
    corpus petitioner may file a traverse, or “the parties may stipulate that the original
    habeas corpus petition be treated as a traverse.” (Id. at p. 477.) If, after
    considering the return and the traverse, we determine there are material facts in
    dispute, we appoint a referee to conduct an evidentiary hearing. (Id. at p. 478.) At
    that hearing, by a preponderance of the evidence, the petitioner must establish
    facts that provide a basis for relief. (In re Crew (2011) 
    52 Cal.4th 126
    , 149; In re
    Bolden, supra, 46 Cal.4th at p. 224.) The main reason for an evidentiary hearing
    is to have the referee determine the credibility of the testimony given at the
    hearing. (In re Thomas (2006) 
    37 Cal.4th 1249
    , 1256.) Because the referee
    observes the demeanor of the witnesses as they testify, we generally defer to the
    referee‟s factual findings and “give great weight” to them when supported by
    substantial evidence. (Ibid.)
    Petitioner‟s claim here is that before his capital trial for the murder of the
    two Guerrero brothers, the prosecution failed to disclose to the defense certain
    information that would have supported a penalty phase case in mitigation that
    petitioner killed under duress. Under the federal Constitution‟s due process
    clause, as interpreted by the high court in Brady v. Maryland, 
    supra,
     
    373 U.S. 83
    ,
    87 (Brady), the prosecution has a duty to disclose to a criminal defendant evidence
    that is “ „both favorable to the defendant and material on either guilt or
    26
    punishment.‟ ” (People v. Earp (1999) 
    20 Cal.4th 826
    , 866; In re Sassounian
    (1995) 
    9 Cal.4th 535
    , 543.) The prosecution‟s withholding of favorable and
    material evidence violates due process “irrespective of the good faith or bad faith
    of the prosecution.” (Brady, 
    supra, at p. 87
    .)
    As the United States Supreme Court has explained, “the term „Brady
    violation‟ is sometimes used to refer to any breach of the broad obligation to
    disclose exculpatory evidence — that is, to any suppression of so-called „Brady
    material‟ — although, strictly speaking, there is never a real „Brady violation‟
    unless the nondisclosure was so serious that there is a reasonable probability that
    the suppressed evidence would have produced a different verdict.” (Strickler v.
    Greene (1999) 
    527 U.S. 263
    , 281, fn. omitted.)
    Favorable evidence is material when “ „it could reasonably be taken to put
    the whole case in such a different light as to undermine confidence in the
    verdict.‟ ” (Strickler v. Green, 
    supra,
     527 U.S. at p. 290, quoting Kyles v. Whitley
    (1995) 
    514 U.S. 419
    , 435.) Put another way, the question is whether, deprived of
    the information withheld by the prosecution, the defendant received “a trial
    resulting in a verdict worthy of confidence.” (Kyles v. Whitley, 
    supra, at p. 434
    .)
    In deciding whether evidence not disclosed to the defense was material
    under these standards, we consider how the nondisclosure affected the defense
    investigation and trial strategy. (People v. Zambrano (2007) 
    41 Cal.4th 1082
    ,
    1132; see United States v. Bagley (1985) 
    473 U.S. 667
    , 683 [“the reviewing court
    may consider any adverse effect that the prosecutor‟s [nondisclosure] might have
    had on the preparation and presentation of the defendant‟s case”].) A
    determination that the prosecution violated its disclosure obligations under Brady,
    
    supra,
     
    373 U.S. 83
    , requires reversal without any need for additional harmless
    error analysis. (Kyles v. Whitley, 
    supra,
     514 U.S. at p. 435; People v. Zambrano,
    supra, at p. 1133.)
    27
    B. Analysis
    At issue here is whether the verdict of death resulting from petitioner‟s
    penalty phase trial is “worthy of confidence.” (Kyles v. Whitley, 
    supra,
     514 U.S.
    at p. 434.) More specifically, we consider how the penalty verdict may have been
    affected by the prosecution‟s failure to disclose to the defense information that it
    had received from the confidential informant, Gale Kesselman.
    In making this assessment, we accept the referee‟s factual findings, which
    we conclude are supported by substantial evidence. As relevant here, the referee
    found that the evidence known to the prosecution but not disclosed to the defense
    included several incriminating statements made to Kesselman by Jose Angarita,
    who was her former boyfriend, a Colombian native, and a major drug trafficker in
    San Jose, California. Kesselman told the prosecution that Angarita told her that he
    was associated with the Medellin drug cartel operating out of Colombia, that he
    himself had arranged the December 1983 killings of the two Guerrero brothers,
    and that the murders were contract killings. Kesselman also told the prosecution
    that she saw Angarita meet petitioner in San Francisco on the night before the
    killings.
    As the referee found, had the prosecution disclosed Kesselman‟s identity to
    the defense, together with the just-described information she had given the
    prosecution, petitioner‟s trial counsel could have called Kesselman as a witness at
    the penalty phase of petitioner‟s capital trial to testify in support of petitioner‟s
    claim to the police that, in killing the Guerrero brothers, he had acted under
    duress. (See § 190.3, factor (g) [at the penalty phase of a capital trial, the trier of
    fact must consider, among other things, “[w]hether or not [the] defendant acted
    under extreme duress or under the substantial domination of another person.”].)
    Her testimony, given as a defense witness at the penalty phase of petitioner‟s
    28
    capital trial, would have enhanced petitioner‟s claim that he had been ordered to
    commit the murders, and by reasonable inference would have supported his further
    claim that this order was accompanied by a threat that he and his entire family
    would be killed if he did not comply. Without this evidence, the jury likely
    disregarded as self-serving and implausible petitioner‟s claims to police that the
    Colombian Mafia had ordered him to kill the Guerrero brothers, and that his entire
    family would have been killed had he disobeyed that order.
    Support for that conclusion is found in the prosecutor‟s arguments to the
    jury at both the guilt and penalty phases of petitioner‟s capital trial. At the guilt
    phase, the prosecutor ridiculed petitioner‟s claim of having acted under Colombian
    Mafia death threats. At the penalty phase, the prosecutor argued that there was
    “no evidence” of duress whatsoever, and that the evidence instead showed that
    petitioner had acted alone and that greed was his sole motive for killing the two
    Guerrero brothers. The prosecutor could not have made those arguments to the
    jury if Kesselman had testified, as part of petitioner‟s penalty phase case in
    mitigation, that a major drug trafficker associated with the Colombian Medellin
    drug cartel had admitted to her that he had arranged the Guerrero killings by
    directing petitioner to murder victim Orestes Guerrero‟s jewelry store. Such
    testimony would have cast the penalty phase case presented to the jury in a
    completely “ „different light.‟ ” (Strickler v. Green, 
    supra,
     527 U.S. at p. 290.)
    Therefore, we cannot be confident that had such testimony been presented to the
    jury, it would have returned a penalty verdict of death. (See Kyles v. Whitley,
    
    supra,
     514 U.S. at p. 435.)3
    3      Some 20 years after petitioner‟s capital trial, one of the witnesses testifying
    on his behalf at the evidentiary hearing was a man whom confidential informant
    Kesselman described at the hearing as a “lieutenant” in Angarita‟s drug trade. For
    (footnote continued on next page)
    29
    The referee found that prosecution investigator Sandra Williams told the
    confidential informant (Gale Kesselman) to withhold evidence at the September
    1985 pretrial ex parte hearing. This conduct, although quite troubling, is not
    determinative here. As the high court observed in Brady, 
    supra,
     
    373 U.S. 83
    , 87,
    good faith or bad faith on the prosecution‟s part plays no role in deciding a due
    process claim that the prosecution has failed to disclose favorable and material
    evidence to the defense.
    At oral argument in this matter, the Attorney General argued that any
    obligation the prosecution may have had to disclose to the defense either Gale
    Kesselman‟s identity or the information she had provided was excused by a
    pretrial ruling that she was not a material witness. We disagree. The ruling in
    question was made by Judge Ambler at the conclusion of an ex parte hearing held
    (footnote continued from previous page)
    safety reasons, the man testified at the hearing under the assumed name of simply
    “Joseph.” (See ante, p. 16.) According to Joseph, shortly before the murders of
    the two Guerrero brothers, petitioner told him that petitioner “had to do a job” for
    Angarita (presumably to commit the murders), and that failure to do so would lead
    to the killings of petitioner‟s entire family, beginning with his mother. Joseph
    attributed to the Colombian Mafia drug cartel the practice of killing the family
    members of those who defied certain orders. It was not disputed at the reference
    hearing that the prosecution at petitioner‟s capital trial did not know of this
    particular information by Joseph and thus could not have disclosed that
    information to the defense. With regard to Joseph, the referee found that if, at
    some point before trial, the prosecution had disclosed to the defense the identity of
    the confidential informant (Kesselman), the defense could have garnered from the
    informant the identity of Joseph, his connection to Angarita‟s drug dealings, and
    his then service in federal prison. That information would have enabled the
    defense to contact Joseph.
    30
    before him in September 1985, and it was limited to whether Kesselman was a
    material witness on the issue of petitioner‟s guilt of the Guerrero brothers‟
    murders. Judge Ambler never addressed whether Kesselman was a material
    witness on the issue of penalty for those murders. As we have stated, the
    prosecution‟s disclosure obligations extend to evidence that is material on either
    guilt or penalty. (See People v. Earp, supra, 20 Cal.4th at p. 866; In re
    Sassounian, 
    supra,
     9 Cal.4th at p. 543.)
    Petitioner has established through evidence that he presented at the
    reference hearing and that the referee found to be credible that the prosecution
    violated its disclosure obligations under Brady, 
    supra,
     
    373 U.S. 83
    , when it
    withheld from the defense the above discussed information it had obtained from
    Gale Kesselman. As the referee found, that information would have supported
    petitioner‟s claim to have acted under Colombian Mafia death threats in his killing
    of the Guerrero brothers. Because substantial evidence supports the referee‟s
    determination, and it is reasonably probable that petitioner‟s penalty phase jury
    would have returned a verdict of life imprisonment without parole had it heard the
    evidence withheld by the prosecution, we grant petitioner‟s requested relief from
    the judgment of death.
    DISPOSITION
    The petition for writ of habeas corpus is granted insofar as it seeks relief
    from the judgment of death. The judgment of the Santa Clara County Superior
    Court in People v. Miguel Angel Bacigalupo, No. 93351, is vacated to the extent
    31
    that it imposes a sentence of death. The petition‟s remaining claims that challenge
    petitioner‟s murder convictions or the special circumstance findings will be
    resolved by later order to be filed separately.
    Upon finality of our opinion, the Clerk of the Supreme Court is to remit a
    certified copy of the opinion and the order to the Santa Clara County Superior
    Court for filing, and respondent Attorney General is to serve a copy of the opinion
    on the prosecuting attorney. (See Pen. Code, § 1382, subd. (a)(2); see also In re
    Sixto (1989) 
    48 Cal.3d 1246
    , 1265-1266; In re Hall (1981) 
    30 Cal.3d 408
    , 435, fn.
    9.)
    KENNARD, J.
    WE CONCUR:
    CANTIL-SAKAUYE, C. J.
    BAXTER, J.
    WERDEGAR, J.
    CHIN, J.
    CORRIGAN, J.
    LIU, J.
    32
    CONCURRING OPINION BY LIU, J.
    I join the court‟s opinion. The prosecution‟s withholding of favorable,
    material evidence that would have been provided by a confidential informant, Gale
    Kesselman, violated petitioner‟s right to due process under Brady v. Maryland
    (1963) 
    373 U.S. 83
    , 87 and entitles him to relief. I write separately to highlight
    three additional points in favor of the court‟s holding.
    The first concerns the significance of Judge Ambler‟s pretrial ruling that
    Kesselman was not a material witness. The court rejects the Attorney General‟s
    argument that “any obligation the prosecution may have had to disclose to the
    defense either Gale Kesselman‟s identity or the information she had provided was
    excused” by that ruling. (Maj. opn., ante, at p. 29.) As the court explains, Judge
    Ambler‟s pretrial ruling “was limited to whether Kesselman was a material
    witness on the issue of petitioner‟s guilt of the Guerrero brothers‟ murders. Judge
    Ambler never addressed whether Kesselman was a material witness on the issue of
    penalty for those murders. As we have stated, the prosecution‟s disclosure
    obligations extend to evidence that is material on either guilt or penalty.” (Ibid.)
    Equally significant, in my view, is the referee‟s finding that prosecution
    investigator Sandra Williams lied and induced Gale Kesselman to lie at the
    September 1985 ex parte hearing that led to Judge Ambler‟s pretrial ruling. After
    hearing Kesselman and Williams testify at the reference hearing, the referee found
    that Kesselman was a credible witness and that Williams was not. The referee
    1
    further found that Williams told Kesselman “to withhold information . . . and not
    to testify to all relevant facts” at the September 1985 hearing. Specifically, the
    referee found that Kesselman “lied” when she denied at the hearing that Angarita
    had given her “any information that he knew [the murders were] contract
    killing[s]” and that Kesselman did so because “Williams had convinced her
    that . . . all she knew was speculation” despite the fact that “Angarita had told
    [Kesselman] in so many words that this was a contract killing.” The referee
    further found that at the September 1985 hearing, “Williams did not testify
    truthfully when she testified . . . that [Kesselman] had no information about the
    murder case” and when Williams answered “no” to the question whether
    Kesselman “indicate[d] in any way that Jose Angarita said that he had heard from
    any source” that the murders were revenge killings. Therefore, Judge Ambler‟s
    determination that Kesselman was not a material witness was, according to the
    referee‟s findings, unmistakably tainted by the prosecution‟s misconduct. That
    misconduct concealed the very information that would have led Judge Ambler to
    conclude that Kesselman was a material witness at least for the penalty phase of
    the trial.
    The second point concerns the referee‟s finding, noted by the court, that
    had the defense gained access to Kesselman, it “would have” uncovered another
    key witness, someone who had worked in Angarita‟s operation and who testified
    at the reference hearing on condition of anonymity using the name “Joseph.”
    Joseph worked for Angarita around the time of the murders and knew a great deal
    about Angarita‟s operation. Kesselman knew Joseph, and she further knew that
    Joseph was in federal prison for sale of cocaine at the time of petitioner‟s trial
    because her cooperation with the Drug Enforcement Agency had helped to put him
    there. A police report in defense counsel‟s possession had identified Joseph as an
    2
    associate of Angarita, but had incorrectly and misleadingly reported that Joseph
    had “bailed and split” and that his whereabouts were unknown.
    The referee found that Joseph was a credible witness. Contrary to the
    Attorney General‟s argument, any minor factual discrepancies in his testimony
    about events that occurred 23 years earlier do not undermine that finding, for we
    assume the referee considered those discrepancies, along with Jospeh‟s demeanor,
    while testifying, before concluding he was a credible witness. (In re Price (2011)
    
    51 Cal.4th 547
    , 559 [“Because the referee observes the demeanor of testifying
    witnesses, and thus has an advantage in assessing their credibility, this court
    ordinarily gives great weight to the referee‟s findings on factual questions.”].)
    From Joseph, the defense would have learned about Angarita‟s drug operation and
    his ruthless methods of enforcement. Critically, the defense also would have
    learned about Angarita‟s statements to Joseph that the murder victims, the
    Guerrero brothers, stole two kilos of cocaine from Angarita and that he wanted
    them killed and intended to have them killed. Joseph also would have
    corroborated Kesselman‟s account of a meeting between petitioner and Angarita
    the night before the murders. Joseph confirmed at the reference hearing that if he
    had been contacted in prison, he would have been willing to provide this
    information to petitioner‟s attorney.
    Most significantly, the referee found that Joseph would have provided
    evidence of a conversation between him and petitioner before the Guerrero
    brothers were murdered. In that conversation, petitioner recounted that Angarita
    had ordered petitioner to do a “job” and that if he did not do it, Angarita would kill
    members of petitioner‟s family, starting with his mother. According to Joseph,
    petitioner‟s eyes were filled with tears as he revealed his predicament, and Joseph
    told him not to do it. This was the last Joseph saw of petitioner. This testimony
    would have strongly corroborated petitioner‟s penalty phase duress defense.
    3
    The Attorney General is not correct that the rule against hearsay evidence
    bars us from considering Joseph‟s testimony. First, Joseph‟s testimony at the
    reference hearing was admissible for the non-hearsay purpose of determining what
    evidence the defense would have uncovered but for the prosecution‟s misconduct,
    a determination directly responsive to the sixth question this court put to the
    referee: “Is it likely that disclosure of the confidential informant‟s identity to the
    defense would have led to evidence not otherwise known or available to the
    defense at the time of trial that would have supported petitioner‟s claim to have
    acted under death threats from the Colombian Mafia?” Second, much of Joseph‟s
    testimony would have been admissible at the penalty phase of petitioner‟s trial had
    Joseph been called as a witness. Joseph‟s testimony recounted statements by
    Angarita that were against Angarita‟s penal interest and hence admissible under
    Evidence Code section 1230 as statements that “subjected [the declarant] to the
    risk of civil or criminal liability.” In addition, Joseph‟s testimony of his
    conversation with petitioner would have been admissible under Evidence Code
    section 1250 as evidence of petitioner‟s then-present state of mind — in particular,
    that petitioner was under duress at the time he committed the murders. (See
    6 Wigmore, Evidence (Chadbourn rev. 1976) § 1714, p. 90 [“the judicial doctrine
    has been that there is a fair necessity, for lack of other better evidence, for
    resorting to a person‟s own contemporary statements of his mental or physical
    condition”].) Further, there is no evidence that petitioner‟s statements to Joseph
    were “made under circumstances such as to indicate its lack of trustworthiness.”
    (Evid. Code, § 1252.)
    As the Attorney General notes, petitioner would have known about his
    conversation with Joseph. But defense counsel — unaware of Joseph‟s
    whereabouts and unable to otherwise corroborate petitioner‟s statement to the
    police that the murder was for hire and committed under duress — reasonably
    4
    concluded that the duress defense was not worth pursuing. Without corroboration,
    the duress defense might have done more harm than good; the jury might have
    viewed it as a deceptive attempt by petitioner to evade responsibility for the
    murders, as the prosecution argued at trial. (Maj. opn., ante, at p. 28.) The
    referee‟s finding that defense counsel would have prepared a credible duress
    defense had they gained access to Kesselman and Joseph is supported by
    substantial evidence in the record.
    Even if the prosecution did not know what testimony Joseph would have
    given at trial, we may still consider that potential testimony in determining the
    materiality of the prosecution‟s failure to disclose evidence supplied by
    Kesselman. As the United States Supreme Court said in United States v. Bagley
    (1985) 
    473 U.S. 667
    , 682, evidence withheld by the prosecution “is material only
    if there is a reasonable probability that, had the evidence been disclosed to the
    defense, the result of the proceeding would have been different.” Importantly, the
    high court made clear that “the reviewing court may consider directly any adverse
    effect that the prosecutor‟s failure to respond might have had on the preparation or
    presentation of the defendant‟s case.” (Id. at p. 683.) We have not previously
    considered the outer limits of this aspect of Brady‟s liability, and we need not do
    so here given the specificity of the referee‟s findings. Here, the referee found, the
    prosecution was aware of, and made a conscious attempt to suppress, the fact that
    Kesselman had substantial information about Jose Angarita and his drug
    trafficking that corroborated petitioner‟s claim of a murder for hire. One of the
    major adverse effects of the prosecution‟s improper efforts to suppress the
    Kesselman evidence and to prevent the defense from contacting Kesselman was
    that the defense failed to uncover the critical evidence corroborating petitioner‟s
    duress defense that Joseph‟s testimony would have provided.
    5
    Third, the referee found that Williams played an active role in discouraging
    defense counsel from pursuing a duress defense. Defense investigator Alayne
    Bolster had conducted a pretrial interview of District Attorney investigator Ron
    McCurdy in February 1986. During that interview, McCurdy disclosed that
    Karlos Tijiboy, whom petitioner had identified as the person who ordered him to
    kill the Guerreros, was involved in Angarita‟s drug trafficking operation.
    McCurdy also described Angarita‟s connections to the victims and to the wife of
    one of the victims. He told Bolster that Angarita had three or four drug lieutenants
    in his drug business, including Joseph. McCurdy also told Bolster that Williams
    might know more.
    When Bolster followed up with Williams, Williams told Bolster that the
    information relayed by McCurdy was incorrect. Williams said that Tijiboy had
    nothing to do with drugs or with Angarita, and that she could find no connection
    between Angarita and the drug trade — even though Williams was clearly aware
    of such a connection, according to the referee‟s findings. She also told Bolster
    that there was no drug-related connection between Angarita and the victims or
    between Angarita and petitioner — even though the referee repeatedly found
    Williams‟s testimony that she saw no connection between Angarita and the
    murders not to be credible.
    According to the referee, “the prosecution through Sandra Williams
    affirmatively told the defense that the information the defense had about any
    putative connection between the killings and a drug-related contract hit was not
    correct.” As a result, defense counsel believed and relied on Williams‟s
    representations that further investigation of a drug connection to the murders
    would be a dead end. Thus, the prosecution did not simply suppress favorable,
    material evidence. It also affirmatively dissuaded the defense from pursuing a line
    6
    of inquiry that would have uncovered such evidence. (See United States v.
    Bagley, 
    supra,
     473 U.S. at p. 682.)
    For purposes of assessing materiality, we must consider collectively all
    undisclosed evidence in order to assess its cumulative effect. (In re Brown (1998)
    
    17 Cal.4th 873
    , 887.) Accordingly, for the reasons above, and for the reasons
    stated in the court‟s opinion, I agree that petitioner is entitled to relief.
    LIU, J.
    WE CONCUR: CANTIL-SAKAUYE, C. J.
    WERDEGAR, J.
    CORRIGAN, J.
    7
    See next page for addresses and telephone numbers for counsel who argued in Supreme Court.
    Name of Opinion In re Bacigalupo
    __________________________________________________________________________________
    Unpublished Opinion
    Original Appeal
    Original Proceeding XXX
    Review Granted
    Rehearing Granted
    __________________________________________________________________________________
    Opinion No. S079656
    Date Filed: August 27, 2012
    __________________________________________________________________________________
    Court: Superior
    County: Santa Clara
    Judge: Thomas Hastings
    __________________________________________________________________________________
    Counsel:
    Robert R. Bryan, under appointment by the Supreme Court, Michael G. Millman, Karen S. Schryver,
    Steven W. Parnes, Robert S. Mahler and Kevin Little for Petitioner Miguel Angel Bacigalupo
    Bill Lockyer, Edmund G. Brown, Jr., and Kamala D. Harris, Attorneys General, David P. Druliner, Robert
    R. Anderson and Dane R. Gillette, Chief Assistant Attorneys General, Ronald A. Bass and Gerald A.
    Engler, Assistant Attorneys General, Ronald S. Matthias, Stan M. Helfman, Glenn R. Pruden and Jeffrey
    M. Laurence, Deputy Attorneys General, for Respondent State of California.
    Counsel who argued in Supreme Court (not intended for publication with opinion):
    Robert R. Bryan
    Law Offices of Robert R. Bryan
    2107 Van Ness Avenue, Suite 203
    San Francisco, CA 94109-2572
    (415) 292-2400
    Jeffrey M. Laurence
    Deputy Attorney General
    455 Golden Gate Avenue, Suite 11000
    San Francisco, CA 94102-7004
    (415) 703-5897