Carriger v. Stewart , 132 F.3d 463 ( 1997 )

SCHROEDER, Circuit Judge:

INTRODUCTION

Paris Hoyt Carriger was convicted and sentenced to death for the brutal murder of Robert Shaw in , 1978. Shaw was beaten on the head with a skillet and strangled with his own necktie’ during a robbery of his Phoenix jewelry store. The chief prosecution witness was Robert Dunbar; Carriger’s defense was that Dunbar committed the murder.

After the trial and unsuccessful appeal, Carriger learned of documents in the state’s records, never disclosed before trial, indicating that Dunbar was a known habitual liar accustomed to blaming others for his own crimes. In our first en banc opinion in the ease, we held that Carriger’s challenge to his counsel’s failure to investigate Dunbar’s background came too late. Carriger v. Lewis, 971 F.2d 329, 333 (9th Cir.1992) (en banc).

After Carriger’s first federal habeas corpus petition had been filed, Dunbar actually confessed in open court that he was the murderer and that Carriger was innocent. Despite the passage of a decade since Dunbar’s sworn confession, and despite numerous attempts by Carriger to raise the issue, we have not yet considered on the merits the effect of Dunbar’s sworn confession on Carri-ger’s continued incarceration and sentence of death.

This habeas proceeding concerns whether Carriger has adequately shown either actual innocence that would foreclose imposition of the death penalty, or sufficient doubt about his guilt to overcome procedural bars and permit consideration of the merits of his constitutional .claims of trial error. The district court and the panel said no. We took the case en banc because of the exceptional importance of the issues concerning whether the state may execute an individual whose guilt is shrouded by doubt and who has raised serious claims of constitutional error at trial. We now hold that we must consider Carriger’s claims, and that those claims warrant a new trial.

I. Procedural History

A. Trial and Sentencing

Carriger was tried in July 1978. The physical evidence at trial was not strong. The prosecution’s case relied principally on the testimony of Robert Dunbar,' who had contacted police the morning following the murder with an offer of information in exchange for immunity. With immunity, Dunbar testified that Carriger had confessed the crime to him immediately after it happened, had described the crime in considerable detail, and had sought Dunbar’s help to dispose of the loot and evidence. Nearly all of the physical evidence used at trial was evidence to which Dunbar had led police the morning following the crime.

Carriger was convicted of robbery and murder. His counsel later testified in post-conviction proceedings that during his investigation and trial preparation he did not take into account that his client faced the death penalty. At the sentencing phase, counsel presented no mitigation ease. The trial judge sentenced Carriger to 99-100 years for the robbery and death for the murder.

B. Appeal

Following sentencing, Carriger dismissed his lawyer and was appointed new counsel. On appeal, Carriger challenged a number of evidentiary rulings, trial counsel’s effectiveness in cross-examining Dunbar, and the constitutionality of Arizona’s death penalty statute. The Arizona Supreme Court affirmed. See State v. Carriger, 123 Ariz. 335, 599 P.2d 788 (1979) (Carriger I).

C. 1982 State Postconviction Proceedings

In 1982, represented by new counsel, Carriger. filed his first petition for state postcon-viction relief. The judge who had presided at Carriger’s trial denied the petition without a hearing. On appeal, the Arizona Supreme Court found- that Carriger’s counsel at sentencing had been ineffective, and ordered a new sentencing hearing. See State v. Carriger, 132 Ariz. 301, 645 P.2d 816, 820 (1982) (Carriger II). The court also ordered that Carriger be given a hearing on his other postconviction claims. See id.

Carriger’s principal postconviction claim was that his trial counsel had been ineffective for failing to investigate Dunbar adequately and for failing to obtain Dunbar’s Department of Corrections file, despite a request from Carriger that he do so. After remand, Carriger for the first time obtained Dunbar’s corrections file through court-ordered discovery. The file contained evidence that Dunbar had long been known to state authorities as an habitual liar with a soeiopathic personality, who had a lengthy history of burglaries, violence, and attémpts at pinning his crimes on others. Counsel called a number of witnesses who testified to Dunbar’s reputation as a liar. The trial court resenteneed Carri-ger to death, and denied postconviction relief. R.T. 10/27/82 at 58, Supp. R.T. 10/27/82 at 14.

The Arizona Supreme Court affirmed, ruling that Carriger’s claim of ineffective assistance was known to Carriger at the time of his appeal, should have been raised then, and had been waived. See State v. Carriger, 143 Ariz. 142, 692 P.2d 991, 995, 996 (1984) (Carriger III). The court also rejected on the merits claims that Carriger was entitled to a lesser-included instruction under the rule of Beck v. Alabama, 447 U.S. 625, 100 S.Ct. 2382, 65 L.Ed.2d 392 (1980), see Carriger III, 692 P.2d at 996—97, and that Arizona’s death penalty was unconstitutional. See id. at 1008-11.

D. 1985: First Federal Habeas

In 1985, Carriger filed his first federal petition for habeas corpus, presenting the claims exhausted in Carriger III. The district court granted Arizona’s motion for summary judgment. Carriger filed a notice of appeal, but soon after requested that this court stay consideration of his appeal while he pursued a new state postconvietion petition, based on newly discovered exculpatory evidence. See Carriger v. Lewis, 971 F.2d 329, 331 (9th Cir.1992) (en banc) (Carriger IV) (superseding Carriger v. Lewis, 948 F.2d 588 (9th Cir.1991) (panel opinion)). We granted Carriger’s motion and stayed his appeal.

E. 1987 State Postconviction Proceedings

Carriger’s second state postconviction petition was based on new information from Dunbar’s family and friends indicating Dunbar had lied at trial regarding his whereabouts during the crime,' had bragged of framing Carriger, and had instructed his family to lie to investigators and at trial.

By 1987, the judge who had presided at Carriger’s trial had retired. At July and August hearings before a new judge, Joyce Stevens (Dunbar’s wife at the time of the murder) and her children testified that Dunbar’s alibi and Stevens’ corroboration of it at trial were false. Stevens also testified that Dunbar left the house that afternoon and upon returning confessed the crime to her. Several witnesses, including a close friend of Dunbar’s, testified that Dunbar had bragged of framing Carriger for the crime. Stevens and her children testified that Dunbar was an abusive person who had beaten them, had previously instructed them to lie, and had threatened their lives if they did not comply. Dunbar then took the stand and denied the allegations of abuse, and stated his trial testimony had been truthful. The evidentiary hearing was continued to permit counsel to investigate further evidence bearing on the credibility of the conflicting testimony given in the July and August hearings.

Not long after his testimony, Dunbar (through his own counsel) contacted Carri-ger’s counsel. Dunbar, imprisoned on an unrelated conviction, was seriously ill. Dunbar said he believed he was dying, wanted to make his peace with God, and then confessed that he had robbed and murdered Robert Shaw, and had framed Carriger.

In October 1987, at the reconvened eviden-tiary hearing, Dunbar confessed under oath. He described the crime in great detail, and diagrammed the jewelry store, accurately depicting where Shaw’s body was found. Dunbar testified that he and Stevens had committed the crime together, and that Stevens had struck the first blow to Mr. Shaw.

Three weeks after his sworn in-court confession, Dunbar wrote to the judge and recanted. Recalled to the stand in December 1987, Dunbar testified that his 1978 tidal testimony had been truthful and his recent sworn confession a lie.

In February 1988, the trial court denied postconviction relief. The judge, who had not presided at trial and therefore could make no demeanor comparisons, rejected both Stevens’ testimony and Dunbar’s confession as incredible, principally because he thought them inconsistent with the trial evidence. The trial court also noted that Stevens recanted her trial testimony after being given immunity, and that Dunbar’s confession was short-lived and motivated by claimed desires for money and revenge. State v. Carriger, No. CR 101609 (Ariz.Sup. Ct. Feb. 22, 1988). The Arizona Supreme Court affirmed without comment.

F. 1991-92: Second Federal Habeas Proceedings

Carriger then returned to federal court, and sought to.raise his claims based on the 1987 state court testimony both in the district court and directly in this court. In a 1992 en banc opinion, we held that Carriger had not followed procedures adequate to give either this court or the district court jurisdiction to .consider his new claims. See Carriger IV, 971 F.2d at 331. As a resuit of those jurisdictional rulings, the merits of Carriger’s claims based on the 1987 evidence were not considered in the 1991-92 federal habeas proceedings, and, until now, have never been considered by this court.

In the 1992 en banc proceeding, we did finally reach the claims raised in Carriger’s first habeas petition, i.e., the claims rejected by the Arizona Supreme Court in Carriger III. A divided en bane court rejected Carri-ger’s ineffective assistance claim as procedurally barred, and rejected on the merits his claim of entitlement to a lesser-included instruction under Beck v. Alabama, and his challenge to the constitutionality of Arizona’s death, penalty statute. See Carriger IV, 971 F.2d at 333-36.

G. 1993: Third State Postconviction Petition

In 1993 Carriger, again represented by new counsel, filed a third state postconviction petition. His petition was based on new evidence that Dunbar had again confessed the crime, this time to a cellmate in 1991, shortly before Dunbar’s death. Carriger also raised numerous other claims, including the claim that the State withheld exculpatory evidence. In 1994, the trial court denied relief. See State v. Carriger, No. CR 101609 (Ariz.Sup.Ct. Apr. 11, 1994). The Arizona Supreme Court affirmed without comment in July 1995.

H. The Current Federal Habeas Proceedings

In August 1995, Carriger filed his current petition, in which he argues that all of the now-available evidence, including Dunbar’s confession and the contents of Dunbar’s corrections file, demonstrates that Dunbar committed the crime and that Carriger is actually innocent. Carriger also raises serious claims of constitutional violations at his trial, including a claim that the state suppressed the contents of the corrections file and that the government misled the jury when it told them Dunbar was not a liar. The district court rejected Carriger’s claim of actual innocence, and held that his claim of withheld evidence could have been raised earlier, and therefore constituted an abuse of the writ. See Carriger v. Stewart, No. CIV-95-1617PHX-PGR, Memorandum of Decision and Order at 10-19, 20-22, (D.Ariz. Nov. 2, 1995).

A panel of this court affirmed the district court’s ruling that Carriger had failed either to show that he was actually innocent of the crime or to create a sufficient doubt about the accuracy of the verdict to permit consideration of his otherwise abusive claims. See Carriger v. Stewart, 95 F.3d 755, 758-61, 762-63 (9th Cir.1996) (Carriger V). The panel expressed considerable doubt about the integrity of the jury’s verdict in light of the present record, and suggested, but did not order, that the state reconsider its decision to execute Carriger. See id. at 761. We granted rehearing en banc. See Garriger v. Stewart, 106 F.3d 1415, 1416 (9th Cir.1997). We now vacate the panel opinion, and reverse the district court. We hold that Carriger is entitled to a new trial.

II. Facts

A. The Robbery and Murder

In December 1977, Paris Carriger was released from prison, and soon contacted Robert Dunbar, a prison acquaintance. Carriger acquired a van and some tools, and began doing construction work. When he needed a place to stay, Dunbar agreed that Carriger could park his van on Dunbar’s property and live in it. On March 12, 1978, Carriger parked his van next to the house Dunbar shared with his wife, Joyce Stevens, and her children.

The next morning, March 13, Carriger called in sick at work. He then spent the day with Dunbar. The two visited a number of gun shops, and Dunbar eventually purchased a .22 caliber Luger pistol. Because it was illegal for Dunbar, a convicted felon, to purchase a gun, Dunbar lied on the federal gun purchase form, falsely claiming to have no felony convictions. Later in the day, the two visited Shaw’s jewelry store, where Dunbar had his watch repaired. After leaving the store, one remarked to the other that the store would be an easy place to “hit.” Dunbar testified at trial that Carriger made this remark, though Dunbar later testified in postconviction proceedings that he said it himself.

The men returned to Dunbar’s house from Shaw’s store between 3:00 and 3:30 p.m., and then went their separate ways. They met again at Dunbar’s house between 5:30 and 6:30 that evening. In the interim, the robbery and murder were committed at Shaw’s jewelry store.

In their later testimony, Dunbar and Car-riger each accused the other of committing the crime. Carriger testified at his 1982 postconviction hearing that upon returning to Dunbar’s house shortly after 3:00, Dunbar got into an argument with his wife, at which point Carriger left in his van and went to a nearby restaurant. Carriger testified he then went shopping for jeans, browsed briefly in an adult bookstore, and returned to Dunbar’s house. Parking his van, he walked to a nearby convenience store and back, finally returning at about 6:00. Carriger testified that shortly after his return, as he sat in his van listening to the radio, Dunbar showed up. According to Carriger, Dunbar had a guilty look, and was holding a pair of Carri-ger’s boots. Dunbar allegedly told Carriger that Carriger should replace the boots because they were “hot,” suggesting Dunbar had worn them during the commission of a crime. Carriger testified that Dunbar then showed Carriger a bag containing a half dozen watches, and offered the watches to satisfy a debt Dunbar owed Carriger. Carriger refused the offer.

Dunbar, on the other hand, testified at trial that upon returning home sometime after 8:15, he retired for a nap with his wife. He said he was awakened sometime between 5:30 and 6:30 by Carriger, who summoned Dunbar outside. According to Dunbar, Car-riger said he had robbed Shaw’s jewelry store, and asked for Dunbar’s help in getting rid of “this stuff.” Dunbar said Carriger took Dunbar outside to his van, where he showed Dunbar an attache ease containing jewelry and watches, and asked for Dunbar’s help in removing the tags. Dunbar testified that together they removed the tags from the jewelry, and placed the tags in a paper bag. Dunbar also testified that Carriger described how he had tied up Shaw and killed him by beating him with a skillet and then choking him with his own necktie.

Dunbar’s and Carriger’s stories agree that after they rejoined at Dunbar’s house, both knew that at least a robbery had been committed. Shortly afterward, Dunbar and Car-riger went out together. Their first stop was the home of Jackie White, Dunbar’s stepdaughter, who had recently moved out of Dunbar’s house and who had a friendly relationship with Carriger. Carriger gave White two small cases, asking her to hold onto them. One of the cases turned out to be the case for the gun Dunbar had purchased that morning and contained only a gun cleaning kit, holster, and manual. The other case, an attache case, contained most of the stolen jewelry, the gun itself, and ammunition. The gun case and the cleaning kit inside it bore Carriger’s - fingerprints. The jewelry inside the attache case, however, bore only Dunbar’s fingerprints, not Carriger’s. The gun yielded no fingerprints.

Carriger and Dunbar then went to a massage parlor. While there, Dunbar produced a loose diamond taken from Shaw’s and tried to sell it to a massage parlor employee. Dunbar and Carriger continued on to a shopping mall,, where Dunbar again tried several times to sell pieces of the stolen jewelry that he had with him. While Dunbar showed the jewelry to a number of mall jewelers, Carri-ger bought new boots. The two then returned to Dunbar’s house.

B. Dunbar’s Role in the Investigation

The following morning, Dunbar contacted detectives of the Phoenix Police Department and told them he had information regarding the murder and robbery. He also told them he had committed a recent (unrelated) burglary, and wanted immunity in exchange for his information and testimony. Detectives met Dunbar at a mall coffee shop, where Dunbar gave them pieces of jewelry taken during the robbery. He told the detectives that Carriger had committed the robbery and murder, and had asked for Dunbar’s help in selling the stolen jewelry and getting rid of the evidence.

Dunbar told the detectives that Carriger might be armed with the handgun Dunbar had purchased the previous day, and that Dunbar considered Carriger to be extremely dangerous. Dunbar said that Carriger would kill police officers if he saw them approaching the residence. At the detectives’ request, Dunbar called Carriger with a lie designed to get Carriger out of the house. Once Carriger left Dunbar’s house, police pulled his van over and arrested him. Carri-ger was unarmed and did not resist arrest.

Dunbar also told the detectives he and Carriger had gone driving north of Phoenix the previous evening to dispose of the evidence. According to Dunbar, Carriger threw evidence out the window as Dunbar drove. After arranging the ruse leading to Carri-ger’s arrest, Dunbar retraced his drive of the previous evening accompanied by a homicide detective, and led the detective to evidence discarded along the roadside, including a jacket, gloves, and boots allegedly worn by Carriger during the robbery, business cards from Shaw Jewelers, Robert Shaw’s wallet and driver’s license, and the cut-up pieces of Shaw’s credit cards. Dunbar also directed police to the home of Ms. White, where they recovered the two cases Carriger had left the previous evening. Finally, Dunbar led police to a pair of jeans in the canal behind Dunbar’s house, where he said Carriger had discarded them. The canal was nearly dry and the jeans were partially submerged in a shallow puddle. The jeans had a piece of one inside pocket cut out in a place where Carri-ger customarily marked his jeans, with his name or initials.

One of the detectives who met Dunbar at the mall testified at trial that the detectives took the story Dunbar told them ,at face value. The same detective stated in a 1994 affidavit that one reason he took Dunbar’s word was that he knew at the time that Dunbar was a longtime informant for the Phoenix Police burglary unit. That status was not made known to the defense or brought out at trial. Dunbar’s history as an informant, as will be discussed, turned out to be somewhat less than reliable, and the detective who knew of Dunbar’s informant status and took his story at face value in 1978 stated in his 1994 affidavit that he now believes Dunbar participated in Shaw’s taurder. Dunbar was never taken into custody, and neither his'person nor his house was ever searched.

C. The Evidence and Arguments at Trial

At trial, Dunbar, granted the immunity he requested, was the state’s chief witness. He testified that he had been home asleep at the time of the robbery, and that Carriger had awakened him and confessed the crime. Dunbar’s wife corroborated Dunbar’s testimony that the two had been asleep together between 4:00 and 6:00 that afternoon.

In closing argument, the prosecutor vouched for Dunbar’s credibility, stating repeatedly that Dunbar was not a liar. The prosecutor assured the jury that “[i]f there was any indication of his [Dunbar’s] guilt or complicity in this, he would be on trial with him [Carriger].”

In addition to Dunbar’s testimony and the physical evidence Dunbar had provided to the police, the state presented two additional pieces of physical evidence against Carriger. The first was a key to the attache case containing the stolen jewelry, which the arresting officer testified was found in Carri-ger’s wallet when he was arrested. The second was a single fingerprint of Carriger’s, which was found on the adhesive tape used to bind the wrists of the victim. The tape was the same type as Carriger kept in a first-aid kit in his van.

Because Carriger did not testify at trial, he offered no direct explanation of the key. Defense counsel did introduce evidence showing it was possible to plant a key in Carriger’s prison property locker, and suggesting that the only keys in Carriger’s possession when he was arrested were keys to his van and Dunbar’s house. The defense explanation of the fingerprint was that the tape was Carri-ger’s, and his fingerprint was already on the end of the roll when Dunbar took the tape from Carriger’s van and used it to commit the crime.

D. Post-trial Discovery of Dunbar’s Corrections File

As a result of court-ordered discovery in the 1982 state postconviction proceedings, Carriger’s counsel for the first time obtained Dunbar’s corrections file. The file revealed that Dunbar was well known by state authorities to be a liar. Using Dunbar’s file, Carri-ger’s 1982 postconviction counsel located prison superintendents, guards and fellow prisoners who testified that Dunbar was a pathological liar, with a reputation for manipulation and deceit well beyond even that expected in the generally dishonest prison environment.

Dunbar’s file showed him to be a prolific career burglar, whose career included committing ninety-two burglaries in one six-month period. Most important, the file revealed a pattern of lying to police and shifting blame to others. After one commercial burglary, Dunbar falsely accused police officers of keeping money they recovered from him after his arrest. After another, Dunbar falsely accused the police of lifting his fingerprints from a water glass and then lying about it. Following a third commercial burglary, Dunbar claimed to have found the money lying in the street, and further claimed to have sought and received legal advice before deciding to keep it. Dunbar’s pattern when caught lying was to seek a deal with the police as soon as possible. Following a 1976 burglary, Dunbar displayed behavior strikingly similar to his behavior following the 1978 Shaw robbery/murder: immediately after committing the burglary, Dunbar, on his own initiative, approached a police officer with a story to shift the blame for his burglary. Dunbar claimed that he had been robbed, and tried to paint the supposed robber as the one who committed the burglary.

Dunbar’s corrections file revealed other facts inconsistent with Dunbar’s trial testimony. Although Dunbar had testified that he was “not a robber” and had never used force, violence, or a gun in a burglary, his file contained admissions that he had committed armed robberies of savings and loans, that he had aided and abetted armed robberies of convenience stores, and that he had used a gun in at least one burglary. The file also contained a claim by Dunbar that he had been involved in a shootout with Phoenix police.

Finally, Dunbar’s file revealed a long history of violence. Dunbar had been committed to the Arizona State Hospital because of violent rages and threats against his family, including an incident in which he wielded a knife against his parents, threatening to kill them. Dunbar was also dishonorably discharged from the Army for uncontrolled aggressive behavior and physical assaults. A presentenee report in the corrections file noted that Dunbar had been found manipulative toward other people, and that he reacted violently when he didn’t get what he wanted. Another report stated that Dunbar had been diagnosed as having a sociopathic personality.

E. Dunbar’s Confessions

In 1987, at an evidentiary hearing on Carrier's postconviction petition, Dunbar confessed under oath in open court that he had robbed Shaw’s jewelry store and murdered Robert Shaw. He testified that he had committed the crime along with his wife, Joyce Stevens, and that he had framed Carriger to avoid prosecution. At the hearing, Dunbar described the crime in detail, including the layout of the store and the back room where Shaw’s body was found. Dunbar accurately described the method of Shaw’s death, and the position in which his body was left. He stated that his wife had first struck Shaw with the skillet, but that he then finished Shaw off with the skillet and the necktie. Dunbar stated that he and his wife had worn gloves during the crime, and that he had bound Shaw’s wrists using adhesive tape from the first-aid kit in Carriger’s van.

Dunbar testified that in the past he had often shifted the blame to others for his own crimes. He said that consistent with his past practice, his thoughts after committing the crime immediately turned to finding someone on whom to pin the blame. That someone, he testified, happened to be Carriger.

Dunbar also confessed the crime in a four-page letter to a woman with whom he corresponded through a prison ministry program. Dunbar’s letter described the crime in sufficiently vivid detail that it frightened the ministry correspondent, who stopped her correspondence with Dunbar. The correspondent has declared in an affidavit that she reported the letter to the Arizona Attorney General’s office, and was asked to forward the letter to them by mail, which she did. The Attorney General’s office never stated whether it received the letter or knows of its whereabouts; the letter itself has never been produced.

Joyce Stevens testified at the 1987 post-conviction hearing that Dunbar had confessed the .crime to her. Several witnesses testified that after a 1981 television special on capital prisoners had included a profile of Carriger, Dunbar boasted that he had set Carriger up. Larry White, Joyce Stevens’ oldest son, also testified that Dunbar once later described to him what it was like to see someone’s head crushed with a skillet.

Shortly before his death in 1991, Dunbar again confessed, this time to his cellmate. He told the cellmate that he had killed Robert Shaw so that Shaw could not identify him, and that he had blamed Carriger to avoid taking the “fall.”

F. Other Postconviction Evidence Implicating Dunbar

Joyce Stevens testified in 1987 that she had lied at trial when she corroborated Dunbar’s alibi that he was napping with her at the time of the robbery. Stevens testified that Dunbar had a common practice of telling the children he was going to take a nap, and then slipping out of the house through a bedroom door leading outside, and committing burglaries while he was supposedly asleep. She stated that Dunbar did just that on the afternoon of March 13, 1978, leaving the house from the bedroom shortly after calling her into the bedroom to join him for a “nap.” According to Stevens, Dunbar later told her he had committed the crime. Stevens explained that she had lied at trial out of fear of Dunbar, who had threatened her life and those of her children if she told the truth.¹

Several of Stevens’ children testified that Dunbar was an abusive and controlling figure, who regularly beat them and instructed them to lie to the prosecution concerning his involvement in this case. Stevens also testified that the day after the robbery,-while she was doing the family laundry, she found the clothes Dunbar had worn the previous day, and that there was blood on the pants that she could not get. out. She testified that when Dunbar saw the blood-stained pants drying on the porch, he became angry that Stevens had found them, and told her to leave his things alone. He took the pants, and she never saw them again.

Richard' Fein, a close friend of Dunbar’s, testified in July 1987 that Dunbar had told him several different times that his favored method of getting rid of evidence was to cut it up into pieces and then drive around the desert, disposing of it a little at a time, so it couldn’t be connected up. Fein also testified that Dunbar described his technique for maintaining a consistent lie when he was shifting blame for his crimes to others.

Finally, both Stevens and her mother testified that Dunbar had often stated that he would never leave a witness to a crime he had committed.

G. Dunbar’s Recantation of His Confession

Dunbar recanted his October 1987 sworn confession in a letter to the judge three weeks later. Recalled to the stand, Dunbar claimed he had falsely confessed because he was angry at Stevens and her children for accusing him, and at the prosecutors and the state because of the length of the unrelated burglary sentence he was then serving and the particulars of his confinement. Dunbar also testified that his attorney was aware Dunbar’s confession , was false, and that the attorney had conspired with Dunbar to present a false story of a frame-up, in hopes of getting a book or movie deal and splitting the proceeds.

Dunbar claimed that the reason his confession testimony had been accurate and detailed was because Carriger’s lawyer had shown him diagrams of the store and transcripts of trial testimony in prehearing meetings with Dunbar. Testimony from Carri-ger’s and Dunbar’s lawyers established that Dunbar had been shown no such diagrams or transcripts, and that Dunbar’s counsel had had nothing to’ do with any scheme by Dunbar to testify falsely and profit from it.

Dunbar admitted at the December 1987 hearing that, given the inconsistency of his separate sworn stories, he had necessarily committed perjury in the Carriger case. He also stated that he had lied to prosecutors “in a lot of different cases and places.” The trial court found Dunbar’s confession was false and his 1978 -trial testimony was truthful.

Dunbar died in 1991.

III. The District Court’s Decision and Its Deference to the State Court’s Credibility Determination

In his current petition, Carriger claims that he is actually innocent of the crime, and that his conviction and death sentence cannot stand because the state failed to disclose exculpatory evidence.² The district court denied relief, ruling that: (1) Carriger had not shown actual innocence sufficient either to bar his execution under Herrera v. Collins, 506 U.S. 390, 113 S.Ct. 853, 122 L.Ed.2d 203 (1993), or to permit consideration of proee-durally barred claims under Schlup v. Delo, 513 U.S. 298, 115 S.Ct. 851, 130 L.Ed.2d 808 (1995); (2) Carriger’s claim of withheld evidence could have been-presented in his first federal habeas petition, and was therefore barred as an abuse of the writ; (3) Carriger had not shown cause or prejudice entitling him to consideration of the otherwise abusive claim, and (4) the claim of withheld evidence was in any event meritless.

Critical to the district court’s conclusion that Carriger had not met the “miscarriage of justice” standard outlined in Schlup was the court’s deference to the Arizona court’s rejection of Dunbar’s 1987 confession and Joyce Stevens’ 1987 testimony implicating Dunbar. The district court noted that the Arizona court found both Dunbar’s confession and Stevens’ testimony incredible, and that witness credibility findings are factual determinations entitled to deference by federal courts if they are fairly supported by the record. See Carriger v. Stewart, No. CIV-95-1617-PHX-PGR, Memorandum of Decision and Order at 15-16 (D.Ariz. Nov. 2, 1995) (citing Marshall v. Lonberger, 459 U.S. 422, 432, 103 S.Ct. 843, 850-51, 74 L.Ed.2d 646 (1983)).

Dunbar’s sworn confession is the most dramatic piece of evidence exonerating Carriger. Before reaching Carriger’s claims, we consider first whether we may rely in any part on Dunbar’s confession, or whether the district court correctly deferred to the state court’s rejection of the confession.

We must defer to the state court’s credibility finding unless the finding is not fairly supported by the record considered as a whole. See 28 U.S.C/§ 2254(d)(8) (1994)³; Marshall v. Lonberger, 459 U.S. 422, 432-35, 103 S.Ct. 843, 849-51, 74 L.Ed.2d 646 (1983). The Arizona e.ourt’s credibility determination, made in 1988 by a judge who had not been the trial judge, was based on the court’s conclusions that the physical evidence at trial was consistent with Dunbar’s trial testimony and inconsistent with his confession, and that Dunbar had motivations to lie in 1987.

With regard to the evidence at trial, the state court pointed specifically to “[Carri-gerj’s fingerprint on the tape binding the victim’s hands, the attache case key found in Petitioner’s property, the discarded clothes with the inside pockets removed where Car-riger customarily placed his initials, Carri-ger’s prints on the gun case, and the boots worn during the robbery which a number of witnesses., in previous proceedings testified belonged to Petitioner.” See State v. Carriger, No. CR 101609, slip op. at 5-6 (Ariz.Sup. Ct. Feb. 22, 1988).

Close examination of this evidence in the context of the entire course of proceedings, however, reveals that each piece of evidence is as consistent with Dunbar’s confession as it is with his trial testimony. We' look at each in turn:

The fingerprint on the tape. Dunbar explained that he had taken the adhesive tape, used to bind Shaw’s hands, from Carriger’s van. The tape belonged to Car-riger, and this would explain Carriger’s fingerprint on the tape. Had Carriger left the print while binding the victim, as the state contends, it is difficult to understand how he could have left only one print. The State points to an offer of proof made at the 1987 hearing, in which a criminalist testified that he had reconstructed the tape and determined that Carriger’s fingerprint was located some 21 inches from an end of the tape. This testimony suggests that the print was left during the binding of Shaw’s hands.

Cross examiriation was able to bring out an internal inconsistency in the expert’s testimony: the expert stated he could piece together all of the segments of tape cut from the victim’s wrists by matching the irregularity of the edges, but admitted he could not match either end of the reconstructed tape to the end of the roll. The state court did not admit the criminalist’s testimony into evidence, and made no findings as to its relationship. The defense never had an opportunity to examine the tape, in either reconstructed or unreconstructed form, or to have its own expert test the state’s criminalist’s conclusions. Although we may consider the offer of proof in our inquiry, we find no basis to conclude the criminalist’s conclusions are reliable and therefore determine they should be accorded little weight.⁴

The attache case key. Dunbar testified that he gave Carriger the attache case to give to Jackie White to hold; he did not explain what he did with the key. He may have given Carriger the key as well.

Alternatively, Dunbar and Carriger may both have had keys to the case. The state court ignored the uncontradicted evidence that the fingerprints on the jewelry inside the case were. Dunbar’s, not Carriger’s.

The discarded clothes. Dunbar testified in his confession that the clothes he led the police to were the clothes he, Dunbar, had worn during the robbery. Nothing establishes that the clothes had been worn by Carriger, rather than Dunbar. (Postconviction evidence established they fit both men.) Additionally, when he confessed, Dunbar stated he planted Carriger’s jeans in the canal before leading police to them. No blood was found on the jeans, despite evidence at trial that blood would likely have spattered on the killer’s pants. The canal was nearly dry at the time.

Carriger’s fingerprints on the gun case. It is undisputed that Carriger and Dunbar were together when Dunbar bought the gun. There is no reason Carriger’s prints would not have been on the gun case.

The discarded boots. Carriger does not dispute the boots were his. He testified in 1982 that Dunbar wore the boots during the crime. Postconviction testimony established that the boots fit Dunbar. In his confession, Dunbar testified that he discarded the clothes he wore during the crime, including the boots, and then, with the police along, re-collected them and said Carriger had worn them. The boots are no more consistent with Carriger’s guilt than with Dunbar’s.

Much of the other physical evidence at trial undercuts Dunbar’s trial testimony, and supports Dunbar’s guilt. First, it is significant that all of the stolen jewelry was in Dunbar’s possession, not Carriger’s. There was no connection between any of the stolen jewelry and Carriger, other than Carriger’s having handed the attache case to Jackie White, and this Dunbar later testified he asked Carriger to do. To explain why the stolen jewelry in the attache case bore only his fingerprints, not Carriger’s, Dunbar claimed that he and Carriger sat together in Carriger’s van removing the tags. If Carri-ger did this without leaving fingerprints on the jewelry, while Dunbar did leave prints, Carriger must have worn gloves while Dunbar did not. Yet Dunbar said nothing at trial about Carriger wearing gloves to remove the tags, despite being questioned specifically about what Carriger was wearing while they removed the tags, and whether he had ever seen Carriger wear gloves. Moreover, if Carriger wore gloves, it is implausible that Dunbar would not have seen them and done the same.

There is other significant evidence supporting the credibility of Dunbar’s confession that was not considered by either the state court or the district court. First, when he confessed to the crime in 1987, Dunbar was able to diagram Shaw’s jewelry store in detail, including the location of the safe and the layout of the back room, and was. able to depict accurately the location and position in which Shaw’s body was found in the bathroom in back of the store. Dunbar could only have known those details if he had participated in the crime.

His knowledge was never adequately explained by any other evidence. According to Dunbar’s trial testimony he had never been in the back of the store: Dunbar’s December 1987 explanation that Carriger’s counsel had shown him diagrams of the store and transcripts of trial testimony was shown to be false. Testimony from all others present at counsel’s meetings with Dunbar established that Dunbar was lying and had been shown no diagrams or transcripts. (During his 1987 in-court confession, Dunbar also testified that he had never seen any diagrams, and that his recollection of the store interior was independent.) Dunbar’s recollection of details only a participant in the crime could have known is strong evidence that his- confession was truthful, and his trial testimony false.

Second, Dunbar’s December 1987 recantation of his confession was itself rife with inconsistencies and false statements. In addition to lying about having been shown diagrams and transcripts, Dunbar claimed that his lawyer had conspired with him to sell a false frameup story and split the book and movie proceeds. Testimony from Dunbar’s lawyer, as well as inconsistencies in Dunbar’s story, established that Dunbar’s lawyer had had nothing to do with any such plan, and that selling the story had been Dunbar’s idea. When asked to explain inconsistencies in his story, Dunbar was vague and evasive, twice resorting to claims of recent mental problems.

Finally, when he confessed the Shaw murder in October 1987, Dunbar testified with no immunity of any kind. He acknowledged on the stand that by confessing, he was opening himself to prosecution for capital murder and a possible sentence of death. By contrast, both at trial and when he recanted his confession in December 1987, Dunbar testified with a grant of testimonial immunity. Asked in December 1987 why he had decided to retract his confession, Dunbar replied, “I don’t believe I recall the exact reason other than I don’t really want to be prosecuted for murder. I don’t want to go on death row.” Dunbar’s admission that he recanted to avoid prosecution makes the recantation highly suspect, while the fact that he confessed without immunity and overwhelmingly against his own penal interest is a strong indicator of reliability. See Williamson v. United States, 512 U.S. 594, 599, 114 S.Ct. 2431, 2435, 129 L.Ed.2d 476 (1994) (discussing Fed.R.Evid. 804(b)(3)); accord 5 Wig-more on Evidence, §§ 1457,1477 (Chadbourn rev.1974).

It is true that Dunbar did not stand by his confession very long, and that Dunbar’s anger at Stevens' and at the prosecution gave him some motivation to lie in 1987. There is virtually no other support for the state court’s rejection of Dunbar’s confession. Much of the physical evidence, Dunbar’s history, and the testimony of other witnesses cuts against it. The entire record, viewed as a whole, does not fairly support the state court’s determination that Dunbar was more credible at trial. On the contrary, the record strongly suggests that Dunbar’s post-trial confession was more reliable than either his trial testimony or his December 1987 recantation. Under 28 U.S.C. § 2254(d)(8), because the state court’s credibility determination is not fairly supported by the record as a whole, it is not entitled to a presumption of correctness. We therefore consider Dunbar’s confession as at least some evidence supporting Carriger’s claims.

IV. Carriger’s Freestanding Claim of Actual Innocence: Herrera v. Collins

Carriger’s first contention in his petition and on appeal is that all of the evidence now available establishes that he is actually innocent of the Shaw robbery and murder. Car-riger argues that the evidence sufficiently establishes his innocence to render his execution unconstitutional, irrespective of any constitutional error at his trial or sentencing. This is a “freestanding” actual innocence claim like that discussed in Herrera v. Collins, 506 U.S. 390, 113 S.Ct. 853, 122 L.Ed.2d 203 (1993), where a majority of the Supreme Court assumed, without deciding, that execution of an innocent person would violate the Constitution. A different majority of the Justices would have explicitly so held. Compare id. at 417, 113 S.Ct. at 869 (majority opinion) with id. at 419, 113 S.Ct. at 870 (O’Connor, J., joined by Kennedy, J., concurring) and id. at 430-37, 113 S.Ct. at 876-79 (Blackmun, J., joined by JJ. Stevens and Souter, dissenting).

In Herrera, the Supreme Court did not specify what showing would be required for a habeas petitioner to make out a successful freestanding claim of actual innocence. The Court stated only that the threshold would be “extraordinarily high,” and that the showing would have to be “truly persuasive.” Herrera, 506 U.S. at 417, 113 S.Ct. at 869; accord id. at 426, 113 S.Ct. at 874 (O’Connor, J., concurring). The Court found it unnecessary to be more specific, because Herrera’s showing was unconvincing under any standard. See id. at 417-19, 113 S.Ct. at 869-70; accord id. at 424-27, 113 S.Ct. at 873-74 (O’Connor, J., concurring).

In this appeal, Carriger argues that he is entitled to relief because “no rational finder of fact could convict beyond a reasonable doubt in light of all the presently available evidence.” Carriger thus urges us to adopt the standard discussed in Justice White’s concurring opinion in Herrera. Justice White, assuming with the majority that a freestanding claim of innocence could entitle a habeas petitioner to relief, stated that the required showing would have to be, at the bare minimum, the same as that required to invalidate a conviction because of insufficient evidence under Jackson v. Virginia, 443 U.S. 307, 324, 99 S.Ct. 2781, 2792, 61 L.Ed.2d 560 (1979), taking into account all the evidence, including both the newly proffered evidence and the evidence at trial. See Herrera, 506 U.S. at 429, 113 S.Ct. at 875 (White, J., concurring in the judgment). Justice White, however, addressed only the minimum required showing; he did not find it necessary to decide finally what the threshold would be. See id. Moreover, Justice White did not speak for a majority.

We conclude that the Herrera majority’s statement that the threshold for a freestanding claim of innocence would have to be “extraordinarily high,” id. at 417, 113 S.Ct. at 869; accord id. at 426, 113 S.Ct. at 874 (O’Connor, J., concurring), contemplates a stronger showing than insufficiency of the evidence to convict. We therefore decline to adopt the modified Jackson standard. We believe that the required showing would have to be at least as high as the more demanding standard articulated by Justice Blaekmun in his Herrera dissent. Justice Blaekmun stated that to be entitled to relief, a habeas petitioner asserting a freestanding innocence claim must go beyond demonstrating doubt about his guilt, and must affirmatively prove that he is probably innocent. See Herrera, 506 U.S. at 442-44, 113 S.Ct. at 882-83 (Blackmun, J., dissenting).

Requiring affirmative proof of innocence is appropriate, because when a petitioner makes a freestanding claim of innocence, he is claiming that he is entitled to relief despite a constitutionally valid conviction. As Justice Blackmun explained,

conviction after a constitutionally adequate trial strips the defendant of the presumption of innocence. The government bears the burden of proving the defendant’s guilt beyond a reasonable doubt, but once the government has done so, the burden of proving innocence must shift to the convicted defendant. The actual-innocence inquiry is therefore distinguishable from review for sufficiency of the evidence, where the question is not whether the defendant is innocent but whether the government has met its constitutional burden of proving the defendant’s guilt beyond a reasonable doubt. When a defendant seeks to challenge the determination of guilt after he has been validly convicted and sentenced, it is fair to place on him the burden of proving his innocence, not just raising doubt about his guilt.

Herrera, 506 U.S. at 443, 113 S.Ct. at 882-83 (Blackmun, J., dissenting); accord id. at 399-400 & 407 n. 6, 113 S.Ct. at 860 & 864 n. 6 (majority opinion) (noting that a valid conviction strips petitioner of the presumption of innocence and attaches a presumption of guilt). In light of the presumption of guilt that attaches after a constitutionally valid conviction, “it is fair to place on [a petitioner asserting a Herrera claim] the burden of proving his innocence, not just raising doubt about his guilt.” Id. at 443, 113 S.Ct. at 883 (Blackmun, J., dissenting).

Carriger has not met this burden. Although the posteonviction evidence he presents casts a vast shadow of doubt over the reliability of his conviction, nearly all of it serves only to undercut the evidence presented at trial, not affirmatively to prove Carri-ger’s innocence. Carriger has presented no evidence, for example, demonstrating he was elsewhere at the time of the murder, nor is there any new and reliable physical evidence, such as DNA, that would preclude any possibility of Carriger’s guilt. Although Dunbar’s confession exonerating Carriger does constitute some evidence tending affirmatively to show Carriger’s innocence, we cannot completely ignore the contradictions in Dunbar’s stories and his history of lying. Accordingly, the confession by itself falls short of affirmatively proving that Carriger more likely than not is innocent. Carriger’s freestanding claim of actual innocence must fail.

V. The “Miscarriage of Justice” Gateway: Schlup v. Delo

Unlike the petitioner-in Herrera, Car-riger accompanies his claim of actual innocence with substantial claims of constitutional violations at trial. The constitutional claims Carriger raises could have been raised in his first federal habeas petition in 1985, and therefore would ordinarily be barred under the abuse of the writ doctrine. See McCleskey v. Zant, 499 U.S. 467, 490, 111 S.Ct. 1454, 1468, 113 L.Ed.2d 517 (1991). Carriger may have his otherwise-barred claims considered on the merits, however, if his claim of actual innocence is sufficient to bring him within the “narrow class of cases-... imph-eating a fundamental miscarriage of justice.” Schlup v. Delo, 513 U.S. 298, 315, 115 S.Ct. 851, 861, 130 L.Ed.2d 808 (1995) (quoting McCleskey, 499 U.S. at 494, 111 S.Ct. at 1470).

The terminology in this area is sometimes confusing, because the “miscarriage of justice” exception; like the freestanding claim in Herrera, has been described as a showing of “actual innocence.” See Murray v. Carrier, 477 U.S. 478, 496, 106 S.Ct. 2639, 2649, 91 L.Ed.2d 397 (1986) (requiring petitioner to show that “a constitutional violation has probably resulted in the conviction of one who is actually innocent”). But unlike a Herrera claim,- the “miscarriage of justice” exception is not an independent avenue to relief. Rather, if established, it functions as a “gateway,” permitting a habeas petitioner to have considered on the merits claims of constitutional error that would otherwise be proeedurally barred. See Schlup, 513 U.S. at 315-16, 115 S.Ct. at 861; Herrera, 506 U.S. at 404, 113 S.Ct. at 862.

In Schlup, the Supreme Court explained that fhe threshold for making out the “miscarriage of justice” exception is lower than the “extraordinarily high” threshold for freestanding (Herrera) claims of innocence, for two reasons. First, the “miscarriage of justice” exception does not itself provide an independent basis for relief. The basis for relief is the claimed underlying constitutional violations. More important, because a petitioner claiming he falls within the miscarriage of justice exception asserts constitutional error at trial, his conviction is not entitled to the same degree of respect as one concededly free of constitutional taint. See Schlup, 513 U.S. at 316, 115 S.Ct. at 861. Accordingly, a petitioner asserting both innocence and constitutional error “need carry less of a burden” with respect to innocence than a petitioner like Herrera who claimed only innocence. See id. While a petitioner making a Herrera claim must present evidence of innocence so strong that his execution would be “ ‘constitutionally intolerable’ even if his conviction was the product of a fair trial,” a petitioner making a miscarriage of justice claim need only present evidence of innocence strong enough “that a court cannot have confidence in the outcome of the trial unless the court is also satisfied that the trial was free of nonharmless constitutional error.” Id. (second emphasis added). In the latter case, “the petitioner should be allowed to pass through the gateway and argue the merits of his underlying claims.” Id.

The Court in Schlup went on to precisely articulate the showing a petitioner must make .to pass through the gateway. The Court held that to permit consideration of his procedurally barred claims, a petitioner must show that in light of all the evidence, including new evidence, “it is more likely than not that no reasonable juror would have found petitioner guilty beyond a reasonable doubt.” Schlup, at 327, 115 S.Ct. at 867. The Court emphasized that in considering all the available evidence, the court is not bound by the rules of admissibility, but must consider “all the evidence, including that alleged to have been illegally admitted (but with. due regard to any unreliability of it) and evidence tenably claimed to have been wrongly excluded or to have become available only after the trial.” Id. (quoting Friendly, Is Innocence Irrelevant? Collateral Attack on Criminal judgments, 38 U. Chi. L.Rev. 142, 160 (1970)).

The dissent incorrectly assumes that in order to prevail on- a Schlup claim, Carri-ger must prove that he is actually innocent. As the Court wrote in Schlup, “[Schlup’s] constitutional claims are based not on his innocence, but rather on his contention that ... the withholding of evidence [citation omitted], denied him the full panoply of protections afforded to criminal defendants by the Constitution.” Schlup v. Delo, 513 U.S. 298, 314, 115 S.Ct. 851, 860, 130 L.Ed.2d 808 (1995). Therefore, the petitioner is required to present “evidence of innocence” such that “a court cannot have confidence in the outcome of the trial.” Id. at 316, 115 S.Ct. at 861. In other words, the claim is procedural, not substantive as the dissent suggests. See id. at 312-14, 115 S.Ct. at 860 (“Schlup’s claim of innocence ... is procedural, rather than substantive.”). The Schlup Court contrasted this showing with that required under a Herrera claim in which the court must find that the “new facts unquestionably establish Schlup’s innocence.” Id. at 316, 115 S.Ct. at 862.

Although Carriger has not affirina-tively proved his actual innocence sufficiently to satis~ Herrera, we believe he has more than shown sufficient doubt about the validity of his conviction to satisfy Schiup and permit consideration of his constitutional claims. It is more likely than not that no reasonable juror hearing all of the now-available evidence would vote to convict Carriger beyond a reasonable doubt. See Schlup, at 326-30, 115 S.Ct. at 867-68.

Considering Dunbar’s confession along with the other evidence, which points as directly to Dunbar as to Carriger, we conclude that Carriger has met the Schlup standard. It is unlikely that any reasonable juror, knowing that Dunbar, without immunity, confessed under oath to committing the murder, would nonetheless conclude beyond a reasonable doubt that the murder was committed by Carriger. We are even more certain that no reasonable juror would vote to convict Carriger beyond a reasonable doubt, if such a juror knew:

- that Dunbar, in his sworn confession, accurately described details about the crime and the crime scene that only a participant could have known;

- that Dunbar's confession explained why Carriger's fingerprint was on the tape, although Carriger was not there;

- that Dunbar had boasted in front of friends and family members that he set Carriger up;

- that Dunbar had described to a close friend how he liked to dispose of evidence by cutting it up and discarding it bits at a time while driving around the desert, as was done in this case;

— that Dunbar had described to the same friend his technique for consistently maintaining a lie when blaming . a crime on someone else;

— that Dunbar had told Stevens’ oldest son how gruesome it was to see someone’s head .crushed with a skillet; and

— that Dunbar had a long history, known to state authorities, of violence, lying to police, and trying to pin his crimes on others. . ,

Because Carriger has satisfied the Schlup gateway standard, we may consider the merits of his otherwise-abusive claims of constitutional error at trial. We therefore turn to the dispositive constitutional claim.

VI. Carriger’s Claim of Constitutional Error at Trial: Brady v. Maryland: Giglio v. United States

Carriger’s strongest claim of constitutional error at trial is that the state withheld Dunbar’s Department of Corrections file, which would have revealed Dunbar’s long history of lying to police and blaming his crimes on others. Carriger argues the state was obligated, under Brady v. Maryland, 373 U.S. 83, 88 S.Ct. 1194, 10 L.Ed.2d 215 (1963), and Giglio v. United States, 405 U.S. 150, 92 S.Ct. 763, 31 L.Ed.2d 104 (1972), to disclose to the defense this critical information bearing on Dunbar’s credibility.

The prosecution is obligated by the requirements of due process to disclose material exculpatory evidence on its own motion, without request. See Kyles v. Whitley, 514 U.S. 419, 432-34, 115 S.Ct. 1555, 1565, 131 L.Ed.2d 490 (1995); United States v. Bagley, 473 U.S. 667, 682, 105 S.Ct. 3375, 3383, 87 L.Ed.2d 481 (1985). Evidence is material, and must be disclosed, “if there is a reasonable probability that, had the evidence been disclosed to the defense, the result of the proceeding would have beén different.” Kyles, at 433, 115 S.Ct. at 1565; Bagley, 473 U.S. at 682, 105 S.Ct. at 3383. A “reasonable probability” does not require showing by a preponderance that the outcome would have been different. See Kyles, at 433-35, 115 S.Ct. at 1565-66. Rather, a “ ‘reasonable probability’ is a probability sufficient to undermine confidence in the outcome.” Bagley, 473 U.S. at 682, 105 S.Ct. at 3383.

Material evidence required to be disclosed includes evidence bearing on the credibility of government witnesses. See Bagley,"473 U.S. at 676, 105 S.Ct. at 3380; Giglio, 405 U.S. at 154-55, 92 S.Ct. at 766. The need for disclosure is particularly acute where the government presents witnesses who have been granted immunity from prosecution in exchange for their testimony. We have previously recognized that criminals who are rewarded by the government for their testimony are inherently untrustworthy, and their use triggers an obligation to disclose material information to protect the defendant from being the victim of a perfidious bargain between the state and its witness. We said that informants granted immunity are

[b]y definition ... cut from untrustworthy cloth[,] and must be managed and carefully watched by the government and the courts to prevent them from falsely accusing the innocent, from manufacturing evidence against those under suspicion of crime, and from lying under oath in the court-room_ Because the government decides whether and when to use such witnesses, and what, if anything, to give them for their service, the government stands uniquely positioned to guard against perfidy_ Accordingly, we expect prosecutors and investigators to take all reasonable measures to safeguard the system against treachery. This responsibility includes the duty as required by Giglio to turn over to the defense in discovery all material information casting a shadow on a government witness’s credibility.

United States v. Bernal-Obeso, 989 F.2d 331, 333-34 (9th Cir.1993).

The record is not conclusive as to whether the individual prosecutors in this ease ever actually possessed Dunbar’s corrections file. The prosécutor’s actual awareness (dr lack thereof) of exculpatory evidence in the government’s hands, however, is not determinative of the prosecution’s disclosure obligations. See Kyles, at 435-40, 115 S.Ct. at 1567-68. Rather, the prosecution has a duty to learn of any exculpatory evidence known to others acting on the government’s behalf. See id., 436-38, 115 S.Ct. at 1567. Because the prosecution is in a unique position to obtain information known to other agents of the government, it may not be excused from disclosing what it does not know but could have learned. See id., at 438-40, 115 S.Ct. at 1568. The disclosure obligation exists, after all, not to police the good faith of prosecutors, but to ensure the accuracy and fairness of trials by requiring the adversarial testing of all available evidence bearing on guilt or innocence. See id., at 438-42, 115 S.Ct. at 1568-69; Brady, 373 U.S. at 87, 83 S.Ct. at 1196-97.

In this case, Dunbar was the prosecution’s star witness, and was known by police and prosecutors to be a career burglar and six-time felon, with a criminal record going back to adolescence. When the state decides to rely on the testimony of such a witness, it is the state’s obligation to turn over all information bearing on that witness’s credibility. See Giglio, 405 U.S. at 154, 92 S.Ct. at 765; Bernal-Obeso, 989 F.2d at 333-34. This must include the witness’s criminal record, including prison records, and any information therein which bears on credibility. The state had an obligation, before putting Dunbar on the stand, to obtain and review Dunbar’s corrections file, and to treat its contents in accordance with the requirements of Brady and Giglio.

To the extent defense counsel’s failure to request the file was a cause of the state’s failure to disclose it, that failure constituted clear ineffective assistance of counsel. Either way, Carriger was denied a fair trial. We do not independently consider the ineffective assistance of counsel issue because the Supreme Court has clarified that the state’s Brady obligations do not depend upon the defense’s discovery requests. See Kyles, at 432-34, 115 S.Ct. at 1565; Bagley, 473 U.S. at 682, 105 S.Ct. at 3383.

The question thus becomes whether the file’s contents are “material,” i.e., whether there is a reasonable probability that disclosure of the file would have led to a different result at trial. See Kyles, at 432-34, 115 S.Ct. at 1565. In deciding whether the withheld evidence satisfies this standard, we evaluate its effect cumulatively, not item-by-item. See id., at 436-38, 115 S.Ct. at 1567..

The contents of the Dunbar file must be deemed to be material. Dunbar’s credibility was critical. As Justice Feldman of the Arizona Supreme Court explained in 1984,

Dunbar was the state’s only direct witness .... There was no direct evidence of Carriger’s guilt. The case was tried, therefore, on a simple basic issue: Did Dunbar tell the truth when he blamed the robbery and murder on Carriger, or was Carriger’s contention that the robbery and murder were committed by Dunbar to be believed? All other issues were peripheral.

Carriger III, 692 P.2d at 1012 (Feldman, J., dissenting).

At trial the prosecution, while acknowledging Dunbar to be a career burglar and convicted felon, nonetheless painted him as a nonviolent and truthful man. Dunbar testified, unrebutted, that he was not capable of murder, that he was not a. robber, and that he had never used force, violence, or a gun in any burglary. Most important, the prosecutor argued at length in closing that Dunbar was not a liar (“He is a burglar, he is a crook.... He is a lot of things but he is not a liar.”). Further vouching for Dunbar’s credibility, the prosecutor assured the jury that “[i]f there was any indication of his [Dunbar’s] guilt or complicity in - this, he would be on trial with him [Carriger].”

While the above picture was painted at trial, the undisclosed information in the state’s files showed:

— that Dunbar had been committed to the Arizona state hospital because of violent rages and threats against his family;

— that Dunbar had brandished a knife at his parents and threatened to kill them;

— that Dunbar was dishonorably discharged from the Army for uncontrolled aggressive and physically as-saultive behavior;

— that Dunbar had in the past- falsely accused police officers of keeping money they recovered from him after arresting him for burglary;

— that Dunbar had falsely denied a burglary and falsely accused the police of lifting his fingerprints from a water glass and lying about it;

— that Dunbar admitted he had been involved in a shootout with a Phoenix policeman;

— that Dunbar had stated he had committed armed robberies of savings and loans in Phoenix and California;

— that Dunbar had also denied ever being involved in bank robberies;

— that Dunbar had been found by authorities to be manipulative toward other people, and that he reacted violently when he didn’t' get what he wanted;

— that a psychiatrist had diagnosed Dunbar as having a “sociopathic personality”;

— that Dunbar had aided two armed robberies of convenience stores, and admitted conspiracy in those robberies;

— that Dunbar had used a gun in at least one burglary; and

— that after committing a 1976 commercial burglary, Dunbar had immediately approached police on his own initiative and attempted to blame the burglary on another.

The defense never received, and the jury never heard, any. of this information. In addition, the jury did not know that the state’s files showed Dunbar committed ninety-two admitted burglaries in the six months following his release from his first burglary sentence. . Had this evidence of Dunbar’s prolificacy in his profession been known, the defense could have used it to question the thoroughness or good faith of an investigation that did not include Dunbar as a suspect. See Kyles, at 444-48, 115 S.Ct. at 1571-72.

The evidence revealed in Dunbar’s file need not have been independently admissible to have been material. Evidence is material if it might have been used’ to impeach a government witness, because “if disclosed and used effectively, it may make the, difference between conviction and acquittal.” Bagley, 473 U.S. at 676, 105 S.Ct. at 3380; accord Giglio, 405 U.S. at 154, 92 S.Ct. at 766; Napue v. Illinois, 360 U.S. 264, 269, 79 S.Ct. 1173, 1177, 3 L.Ed.2d 1217 (1959) (“The jury’s estimate of the truthfulness and reliability of a given witness may well be determinative of guilt or innocence .... ”); see also Kyles, at 444-52, 115 S.Ct. at 1571-74 (discussing impeaching uses of undisclosed evidence). As we have observed, “[t]he established safeguards of the Anglo-American legal system leave the veracity of a witness to be tested by cross-examination.” Bernal-Obeso, 989 F.2d at 335. It is for precisely that reason that we require “that relevant evidence bearing on the credibility of an informant-witness be timely revealed” to the defense. Id.

The district court erred when it concluded that Carriger had not been prejudiced by the withholding of the information because the jury already knew Dunbar was a burglar testifying with immunity. The telling evidence that remained undisclosed included the length of Dunbar’s record of burglaries, and, more important, his long history of lying to the police and blaming others to cover up his own guilt.

The district court also noted that the jury had already heard “a wealth of negative information about Dunbar’s veracity.” However, the only evidence before the jury that Dunbar had lied was his admission that he had, falsified the gun registration form. There was no evidence concerning his long history of falsely blaming others for his misdeeds. Furthermore, although the jury heard Dunbar admit he had once slapped his stepdaughter, they heard no evidence of Dunbar’s lifelong history of violence. The latter evidence, had it been disclosed, would have been relevant to Carriger’s defense that Dunbar did it, and to the related issues of the quality of the investigation, and the decision not to charge Dunbar.

We have held that the government cannot satisfy its Brady obligation to disclose exculpatory evidence by making some evidence available and claiming the rest would be. cumulative. See Bernal-Obeso, 989 F.2d at 335. Rather, the government is obligated to disclose “all material information casting a shadow on a government witness’s credibility.” Id. at 334 (emphasis in original).

In this particular case the state’s claim that the undisclosed information made no difference is severely undercut by the prosecutor’s strenuous vouching for Dunbar’s truthfulness in closing argument. The prosecutor acknowledged that the whole case came down to whether Dunbar was telling the truth, or whether, as Carriger contended, Dunbar did it and framed Carriger. R.T. 7/25/78 at 464. Knowing Dunbar’s credibility was the key to the case, the prosecutor emphasized to the jury that even though Dunbar was a career burglar, he was a truthful man:

[H]e is a smart cookie, he is a burglar, he is a crook. He is not a liar. Remember when the probation officer was on the stand. Did you ever catch him in a lie-never. Ever catch him in a lie-no_ What I am trying to put across, I don’t want you [the jury] to get in the position of falling to that kind of logic, letting a murderer go because he is taking pot shots at our star witness. That is the important thing to remember. If there was any indication of his [Dunbar’s] guilt or complicity in this, he would be on trial with him.

Remember, I asked him on the stand, what did I tell you is going to happen to you if you tell a lie, what did I tell you is going to happen to you, what is the penalty for lying in a perjury case? He knew right away, ladies and gentlemen, he did not lie to you. He is a lot of things but he is not a liar.

Id. at 463-64. Entirely apart from being itself improper conduct, see United States v. Young, 470 U.S. 1, 18-19, 105 S.Ct. 1038, 1048, 84 L.Ed.2d 1 (1985); Berger v. United States, 295 U.S. 78, 88-89, 55 S.Ct. 629, 633, 79 L.Ed. 1314 (1935), the prosecutor’s vouching underscores the centrality of Dunbar’s credibility.

We conclude that there is more than a reasonable probability that the outcome of Carriger’s trial would have been different had Dunbar’s records been disclosed. The result was a verdict not worthy of confidence and a trial that denied Carriger due process of law. Carriger is entitled to a new trial.

The panel opinion, 95 F.3d 755, is VACATED.

The district court’s judgment is REVERSED AND REMANDED WITH INSTRUCTIONS TO GRANT THE WRIT OF HABEAS CORPUS.

1 . The dissent seizes upon an inconsistency between Dunbar’s confession, which stated that he and Joyce committed the murder, and Joyce's recantation, which stated that Dunbar left the house alone. The dissent concludes that Joyce’s recantation does not exonerate Carriger but supports the inference that Dunbar and Carriger acted together. There is no basis for this conclusion; the inference that Dunbar acted alone is at least equally plausible. There is no evidence that Dunbar and Carriger acted together to commit the murder.

2 . Because these claims are sufficient to dispose of Carriger’s case, we need not consider his additional claims that he is entitled to resentenc-ing based on a new mitigating circumstance, that he was incompetent to be tried or sentenced, or that his counsel at resentencing was ineffective for failing to raise the competency issues.

3 . Because Carriger’s petition was filed prior to the enactment of the Antiterrorism and Effective Death Penalty Act of 1996, Pub.L. No. 104-132, 110 Stat. 1214 (the "Act”), we apply § 2254(d)(8) as it existed prior to its amendment by the Act. See Jeffries v. Wood, 114 F.3d 1484, 1495-96 (9th Cir. 1997) (en banc); accord Lindh v. Murphy, -U.S. -, ---, 11.7 S.Ct. 2059, 2068, 138 L.Ed.2d 481 (1997) (”[T]he new provisions of chapter 153 generally apply only to cases filed after the Act became effective.”).

4 . The dissent argues that this offer of proof is “the single most damning piece of proof,” infra at 490, and concludes that even after disregarding Dunbar's testimony, “reasonable jurors ... could and would still find plenty on which to convict Carriger," infra at 487. We do not agree with the assumption that the reconstruction is reliable or that our test under Schlup is to decide how a hypothetical jury would regard each bit of new evidence. Our task is to determine whether confidence in the actual verdict is undermined. Schlup, at 314-16, 115 S.Ct. at 861.