dissenting.
I would grant defendants a new trial. The Government deprived defense counsel of the best weapons it could have used to impeach the truthfulness of the Government’s witnesses, Ronald Bergantzel and Merle Vermuele. This result followed from the withholding of police reports summarizing statements made by those witnesses which contradicted their trial testimony. Because attacking the testimony of those witnesses would have materially affected the outcome of Tallman and Green’s trial, see Brady v. Maryland, 373 U.S. 83, 87, 83 S.Ct. 1194, 1196, 10 L.Ed.2d 215 (1963), I dissent from this court’s decision affirming their convictions.
Ronald Bergantzel provided the Government with its sole source of information on many aspects of Tallman and Green’s drug trafficking activities. Bergantzel alone testified that Tallman bought and sold massive amounts of cocaine, providing evidence that would serve as the basis for Tallman’s nineteen-year sentence and Green’s eight-year sentence. Yermuele also testified that he purchased cocaine from both Green and Tallman and sold cocaine that he bought from Tallman to law enforcement officers.
The Government admits that it improperly withheld reports of statements by Ber-gantzel and Vermuele to police. Those reports show that, when first questioned by police, they denied any involvement in drug trafficking. The existence and admission of that evidence would have presented two alternative choices for the jury. If what Bergantzel and Vermuele had told police was true, then they lied under oath in testifying to the contrary. If their trial testimony, detailing extensive involvement in drug trafficking with Tallman and Green, was true, then they gave false statements to police officers when first questioned. Either way, this evidence proved that the witnesses lied; that they were unreliable witnesses who changed their stories and implicated their friends in drug activities to avoid long prison sentences for themselves. The jury, and not the district court, should have decided whether those witnesses were credible.
Although Tallman’s counsel ably cross-examined Bergantzel, counsel did not possess evidence discrediting Bergantzel’s truthfulness. Counsel pointed to ambiguities in Bergantzel’s memory of the facts, to the benefit Bergantzel received for cooperating with the Government and that Ber-gantzel was in jail at the time of trial because he had tested positive for marijuana in violation of his probation, IV Tr. at 532. However, defense counsel possessed no evidence that Bergantzel at one time had told police a different story than the one he told on the stand. The suppressed evidence, vital to impeachment, was not cumulative. Cf. United States v. Roberts, *170848 F.2d 906, 908 (8th Cir.) (holding withheld evidence not material when counsel effectively cross-examined without withheld evidence, or when withheld evidence was cumulative), cert. denied, 488 U.S. 931, 109 S.Ct. 322, 102 L.Ed.2d 340 (1988).
The district court determined that the Government submitted ample evidence implicating Tallman and Green, making Ber-gantzel’s and Vermuele’s testimony not material to the outcome of the trial. Specifically, the district court found that tapes of conversations between the defendants discussing drug dealing, physical evidence found at Tallman’s apartment (large amounts of cash, guns and cocaine) and testimony of other witnesses proved beyond a reasonable doubt that Tallman and Green were guilty of the crimes for which they were convicted.
For the jury to convict Tallman of the crimes charged, it needed to find Bergant-zel’s version of the facts credible. The jury found Tallman guilty of counts I, V, VI, VII and VIII, and Green guilty of counts I, V, VI and VII. Other evidence at trial, besides Bergantzel’s and Vermuele’s testimony, corroborated count I, which involved Tallman and Green conspiring to distribute cocaine, and count VIII, which related to Tallman possessing cocaine with intent to distribute.
The jury also found Tallman and Green guilty on counts V, VI and VII, relating to sales to undercover agents of cocaine by Terri Langston and Vincent Handy. Handy, who sold cocaine to an undercover agent, testified that he purchased his cocaine from Bergantzel, II Tr. at 232-34; III Tr. at 235-55. Bergantzel identified Tall-man as his sole supplier of cocaine. Ill Tr. at 321-25. Bergantzel never identified the supplier to Handy, referring to the supplier only as “Milk and Toast.” Ill Tr. at 255-56. Only Bergantzel’s testimony connects Tallman and Green to Handy’s sales of drugs to an undercover agent. If the jury discredited Bergantzel as a witness, the jury might have determined the evidence insufficient to establish Tallman as the sole supplier of cocaine to Bergantzel.3 The issue of Bergantzel’s credibility became very material to Tallman’s and Green’s convictions on counts V, VI and VII.
Despite defense counsel’s inability to impeach Bergantzel and Vermuele and the existence of other evidence of drug dealing by defendants, the jury apparently believed this to be a close case, acquitting Tallman of two charges and acquitting Green of three charges. The jury deliberated for several days, asked the district court for assistance on numerous occasions and sent the district court a note indicating that some jurors were harassing a juror with a minority opinion. At one point during the course of deliberations, the district court remarked “counsel have rightly indicated that there are indicia of the jury’s [sic] having difficulty arriving at a decision.” IV Tr. at 950.
As Justice Blackmun has noted, a reasonable probability is one that would “undermine confidence in the outcome” of the proceeding. United States v. Bagley, 473 U.S. 667, 682, 105 S.Ct. 3375, 3383, 87 L.Ed.2d 481 (1985). In light of this evidence discrediting the Government’s main witness, we cannot be confident that the jury would have convicted.
Impeachment evidence also becomes material under Brady if it discredits testimony crucial to a defendant’s sentence. Pennsylvania v. Ritchie, 480 U.S. 39, 57, 107 S.Ct. 989, 1001, 94 L.Ed.2d 40 (1987). Only Bergantzel’s testimony connects Tail-man and Green to at least five kilograms of cocaine, resulting in Tallman’s nineteen-year sentence and Green’s eight-year sentence under the Guidelines. Although others testified to seeing Tallman handling kilos of cocaine, Bergantzel’s testimony *171provides the sole basis for connecting Tail-man to five kilos. If defense counsel could have confronted Bergantzel and effectively impeached him on cross-examination, Ber-gantzel’s reliability would have been in question. A reasonable probability exists that the district court may have assessed Tallman and Green as being responsible for a smaller amount of drugs, resulting in a lesser sentence.
Accordingly, I dissent and would grant Tallman and Green a new trial, permitting them to fully cross-examine the Government’s witnesses Bergantzel and Vermuele utilizing the withheld documents.
. This is not to say that no other evidence ties Tallman to the cocaine purchased by Handy. Terri Wentworth testified that Bergantzel referred to Tallman as “Milk and Toast,” IV Tr. at 773, and Bergantzel told Handy that his source had that name. Also, the cocaine that Bergant-zel gave Handy was packaged in the same manner that Wentworth testified that Tallman packaged his cocaine, wrapped in folded magazine paper and placed in a plastic bag, IV Tr. at 748. This circumstantial evidence does not foreclose the possibility that Bergantzel testified falsely about Tallman being his sole supplier.