United States v. Bagley , 105 S. Ct. 3375 ( 1985 )

Justice Blackmun

announced the judgment of the Court and delivered an opinion of the Court except as to Part III.

In Brady v. Maryland, 373 U. S. 83, 87 (1963), this Court held that “the suppression by the prosecution of evidence favorable to an accused upon request violates due process where the evidence is material either to guilt or punishment.” The issue in the present case concerns the standard of materiality to be applied in determining whether a conviction should be reversed because the prosecutor failed to disclose requested evidence that could have been used to impeach Government witnesses.

I-H

In October 1977, respondent Hughes Anderson Bagley was indicted in the Western District of Washington on 15 charges of violating federal-narcotics and firearms statutes. On November 18, 24 days before trial, respondent filed a discovery motion. The sixth paragraph of that motion requested:

“The names and addresses of witnesses that the government intends to call at trial. Also the prior criminal records of witnesses, and any deals, promises or inducements made to witnesses in exchange for their testimony.” App. 18.¹

The Government’s two principal witnesses at the trial were James F. O’Connor and Donald E. Mitchell. O’Connor and Mitchell were state law enforcement officers employed by the Milwaukee Railroad as private security guards. Between April and June 1977, they assisted the federal Bureau of Alcohol, Tobacco and Firearms (ATF) in conducting an undercover investigation of respondent.

The Government’s response to the discovery motion did not disclose that any “deals, promises or inducements” had been made to O’Connor or Mitchell. In apparent reply to a request in the motion’s ninth paragraph for “[c]opies of all Jencks Act material,”² the Government produced a series of affidavits that O’Connor and Mitchell had signed between April 12 and May 4, 1977, while the undercover investigation was in progress. These affidavits recounted in detail the undercover dealings that O’Connor and Mitchell were having at the time with respondent. Each affidavit concluded with the statement, “I made this statement freely and voluntarily without any threats or rewards, or promises of reward having been made to me in return for it.”³

Respondent waived his right to a jury trial and was tried before the court in December 1977. At the trial, O’Connor and Mitchell testified about both the firearms and the narcotics charges. On December 23, the court found respondent guilty on the narcotics charges, but not guilty on the firearms charges.

In mid-1980, respondent filed requests for information pursuant to the Freedom of Information Act and to the Privacy Act of 1974, 5 U. S. C. §§552 and 552a. He received in response copies of ATF form contracts that O’Connor and Mitchell had signed on May 3, 1977. Each form was entitled “Contract for Purchase of Information and Payment of Lump Sum Therefor.” The printed portion of the form stated that the vendor “will provide” information to ATF and that “upon receipt of such information by the Regional Director, Bureau of Alcohol, Tobacco and Firearms, or his representative, and upon the accomplishment of the objective sought to be obtained by the use of such information to the satisfaction of said Regional Director, the United States will pay to said vendor a sum commensurate with services and information rendered.” App. 22 and 23. Each form contained the following typewritten description of services:

“That he will provide information regarding T-I and other violations committed by Hughes A. Bagley, Jr.; that he will purchase evidence for ATF; that he will cut [sic] in an undercover capacity for ATF; that he will assist ATF in gathering of evidence and testify against the violator in federal court.” Ibid.

The figure “$300.00” was handwritten in each form on a line entitled “Sum to Be Paid to Vendor.”

Because these contracts had not been disclosed to respondent in response to his pretrial discovery motion,⁴ respondent moved under 28 U. S. C. § 2255 to vacate his sentence. He alleged that the Government’s failure to disclose the contracts, which he could have used to impeach O’Connor and Mitchell, violated his right to due process under Brady v. Maryland, supra.

The motion came before the same District Judge who had presided at respondent’s bench trial. An evidentiary hearing was held before a Magistrate. The Magistrate found that the printed form contracts were blank when O’Connor and Mitchell signed them and were not signed by an ATF representative until after the trial. He also found that on January 4, 1978, following the trial and decision in respondent’s case, ATF made payments of $300 to both O’Connor and Mitchell pursuant to the contracts.⁵ Although the ATF case agent who dealt with O’Connor and Mitchell testified that these payments were compensation for expenses, the Magistrate found that this characterization was not borne out by the record. There was no documentation for expenses in these amounts; Mitchell testified that his payment was not for expenses, and the ATF forms authorizing the payments treated them as rewards.

The District Court adopted each of the Magistrate’s findings except for the last one to the effect that “[n]either O’Connor nor Mitchell expected to receive the payment of $300 or any payment from the United States for their testimony.” App. to Pet. for Cert. 7a, 12a, 14a. Instead, the court found that it was “probable” that O’Connor and Mitchell expected to receive compensation, in addition to their expenses, for their assistance, “though perhaps not for their testimony.” Id., at 7a. The District Court also expressly rejected, ibid., the Magistrate’s conclusion, id., at 14a, that:

“Because neither witness was promised or expected payment for his testimony, the United States did not withhold, during pretrial discovery, information as to any ‘deals, promises or inducements’ to these witnesses. Nor did the United States suppress evidence favorable to the defendant, in violation of Brady v. Maryland, 373 U. S. 83 (1963).”

The District Court found beyond a reasonable doubt, however, that had the existence of the agreements been disclosed to it during trial, the disclosure would have had no effect upon its finding that the Government had proved beyond a reasonable doubt that respondent was guilty of the offenses for which he had been convicted. Id., at 8a. The District Court reasoned: Almost all of the testimony of both witnesses was devoted to the firearms charges in the indictment. Respondent, however, was acquitted on those charges. The testimony of O’Connor and Mitchell concerning the narcotics charges was relatively very brief. On cross-examination, respondent’s counsel did not seek to discredit their testimony as to the facts of distribution but rather sought to show that the controlled substances in question came from supplies that had been prescribed for respondent’s personal use. The answers of O’Connor and Mitchell to this line of cross-examination tended to be favorable to respondent. Thus, the claimed impeachment evidence would not have been helpful to respondent and would not have affected the outcome of the trial. Accordingly, the District Court denied respondent’s motion to vacate his sentence.

The United States Court of Appeals for the Ninth Circuit reversed. Bagley v. Lumpkin, 719 F. 2d 1462 (1983). The Court of Appeals began by noting that, according to precedent in the Circuit, prosecutorial failure to respond to a specific Brady request is properly analyzed as error, and a resulting conviction must be reversed unless the error is harmless beyond a reasonable doubt. The court noted that the District Judge who had presided over the bench trial concluded beyond a reasonable doubt that disclosure of the ATF agreement would not have affected the outcome. The Court of Appeals, however, stated that it “disagree[d]” with this conclusion. Id., at 1464. In particular, it disagreed with the Government’s — and the District Court’s — premise that the testimony of O’Connor and Mitchell was exculpatory on the narcotics charges, and that respondent therefore would not have sought to impeach “his own witness.” Id., at 1464, n. 1.

The Court of Appeals apparently based its reversal, however, on the theory that the Government’s failure to disclose the requested Brady information that respondent could have used to conduct an effective cross-examination impaired respondent’s right to confront adverse witnesses. The court noted: “In Davis v. Alaska, . . . the Supreme Court held that the denial of the ‘right of effective cross-examination’ was ‘ “constitutional error of the first magnitude” ’ requiring automatic reversal.” 719 F. 2d, at 1464 (quoting Davis v. Alaska, 415 U. S. 308, 318 (1974)) (emphasis added by Court of Appeals). In the last sentence of its opinion, the Court of Appeals concluded: “we hold that the government’s failure to provide requested Brady information to Bagley so that he could effectively cross-examine two important government witnesses requires an automatic reversal.” 719 F. 2d, at 1464.

We granted certiorari, 469 U. S. 1016 (1984), and we now reverse.

II

The holding in Brady v. Maryland requires disclosure only of evidence that is both favorable to the accused and “material either to guilt or to punishment.” 373 U. S., at 87. See also Moore v. Illinois, 408 U. S. 786, 794-795 (1972). The Court explained in United States v. Agurs, 427 U. S. 97, 104 (1976): “A fair analysis of the holding in Brady indicates that implicit in the requirement of materiality is a concern that the suppressed evidence might have affected the outcome of the trial.” The evidence suppressed in Brady would have been admissible only on the issue of punishment and not on the issue of guilt, and therefore could have affected only Brady’s sentence and not his conviction. Accordingly, the Court affirmed the lower court’s restriction of Brady’s new trial to the issue of punishment.

The Brady rule is based on the requirement of due process. Its purpose is not to displace the adversary system as the primary means by which truth is uncovered, but to ensure that a miscarriage of justice does not occur.⁶ Thus, the prosecutor is not required to deliver his entire file to defense counsel,⁷ but only to disclose evidence favorable to the accused that, if suppressed, would deprive the defendant of a fair trial:

“For unless the omission deprived the defendant of a fair trial, there was no constitutional violation requiring that the verdict be set aside; and absent a constitutional violation, there was no breach of the prosecutor’s constitutional duty to disclose. . . .

“. . . But to reiterate a critical point, the prosecutor will not have violated his constitutional duty of disclosure unless his omission is of sufficient significance to result in the denial of the defendant’s right to a fair trial.” 427 U. S., at 108.

In Brady and Agurs, the prosecutor failed to disclose exculpatory evidence. In the present case, the prosecutor failed to disclose evidence that the defense might have used to impeach the Government’s witnesses by showing bias or interest. Impeachment evidence, however, as well as exculpatory evidence, falls within the Brady rule. See Giglio v. United States, 405 U. S. 150, 154 (1972). Such evidence is “evidence favorable to an accused,” Brady, 873 U. S., at 87, so that, if disclosed and used effectively, it may make the difference between conviction and acquittal. Cf. Napue v. Illinois, 360 U. S. 264, 269 (1959) (“The jury’s estimate of the truthfulness and reliability of a given witness may well be determinative of guilt or innocence, and it is upon such subtle factors as the possible interest of the witness in testifying falsely that a defendant’s life or liberty may depend”).

The Court of Appeals treated impeachment evidence as constitutionally different from exculpatory evidence. According to that court, failure to disclose impeachment evidence is “even more egregious” than failure to disclose exculpatory evidence “because it threatens the defendant’s right to confront adverse witnesses.” 719 F. 2d, at 1464. Relying on Davis v. Alaska, 415 U. S. 308 (1974), the Court of Appeals held that the Government’s failure to disclose requested impeachment evidence that the defense could use to conduct an effective cross-examination of important prosecution witnesses constitutues “‘constitutional error of the first magnitude’” requiring automatic reversal. 719 F. 2d, at 1464 (quoting Davis v. Alaska, supra, at 318).

This Court has rejected any such distinction between impeachment evidence and exculpatory evidence. In Giglio v. United States, supra, the Government failed to disclose impeachment evidence similar to the evidence at issue in the present case, that is, a promise made to the key Government witness that he would not be prosecuted if he testified for the Government. This Court said:

“When the ‘reliability of a given -witness may well be determinative of guilt or innocence/ nondisclosure of evidence affecting credibility falls -within th[e] general rule [of Brady]. We do not, however, automatically require a new trial whenever ‘a combing of the prosecutors’ files after the trial has disclosed evidence possibly useful to the defense but not likely to have changed the verdict . . . A finding of materiality of the evidence is required under Brady. ... A new trial is required if ‘the false testimony could ... in any reasonable likelihood have affected the judgment of the jury . . . 405 U. S., at 154 (citations omitted).

Thus, the Court of Appeals’ holding is inconsistent with our precedents.

Moreover, the court’s reliance on Davis v. Alaska for its “automatic reversal” rule is misplaced. In Davis, the defense sought to cross-examine a crucial prosecution witness concerning his probationary status as a juvenile delinquent. The defense intended by this cross-examination to show that the witness might have made a faulty identification of the defendant in order to shift suspicion away from himself or because he feared that his probationary status would be jeopardized if he did not satisfactorily assist the police and prosecutor in obtaining a conviction. Pursuant to a state rule of procedure and a state statute making juvenile adjudications inadmissible, the trial judge prohibited the defense from conducting the cross-examination. This Court reversed the defendant’s conviction, ruling that the direct restriction on the scope of cross-examination denied the defendant “the right of effective cross-examination which “‘would be constitutional error of the first magnitude and no amount of showing of want of prejudice would cure it.” Brookhart v. Janis, 384 U. S. 1, 3.’” 415 U. S., at 318 (quoting Smith v. Illinois, 390 U. S. 129, 131 (1968)). See also United States v. Cronic, 466 U. S. 648, 659 (1984).

The present case, in contrast, does not involve any direct restriction on the scope of cross-examination. The defense was free to cross-examine the witnesses on any relevant subject, including possible bias or interest resulting from inducements made by the Government. The constitutional error, if any, in this case was the Government’s failure to assist the defense by disclosing information that might have been helpful in conducting the cross-examination. As discussed above, such suppression of evidence amounts to a constitutional violation only if it deprives the defendant of a fair trial. Consistent with “our overriding concern with the justice of the finding of guilt,” United States v. Agurs, 427 U. S., at 112, a constitutional error occurs, and the conviction must be reversed, only if the evidence is material in the sense that its suppression undermines confidence in the outcome of the trial.

Ill

A

It remains to determine the standard of materiality applicable to the nondisclosed evidence at issue in this case. Our starting point is the framework for evaluating the materiality of Brady evidence established in United States v. Agurs. The Court in Agurs distinguished three situations involving the discovery, after trial, of information favorable to the accused that had been known to the prosecution but unknown to the defense. The first situation was the prosecutor’s knowing use of perjured testimony or, equivalently, the prosecutor’s knowing failure to disclose that testimony used to convict the defendant was false. The Court noted the well-established rule that “a conviction obtained by the knowing use of perjured testimony is fundamentally unfair, and must be set aside if there is any reasonable likelihood that the false testimony could have affected the judgment of the jury.” 427 U. S., at 103 (footnote omitted).⁸ Although this rule is stated in terms that treat the knowing use of perjured testimony as error subject to harmless-error review,⁹ it may as easily be stated as a materiality standard under which the fact that testimony is perjured is considered material unless failure to disclose it would be harmless beyond a reasonable doubt. The Court in Agurs justified this standard of materiality on the ground that the knowing use of perjured testimony involves prosecutorial misconduct and, more importantly, involves “a corruption of the truth-seeking function of the trial process.” Id., at 104.

At the other extreme is the situation in Agurs itself, where the defendant does not make a Brady request and the prosecutor fails to disclose certain evidence favorable to the accused. The Court rejected a harmless-error rule in that situation, because under that rule every nondisclosure is treated as error, thus imposing on the prosecutor a constitutional duty to deliver his entire file to defense counsel.¹⁰ 427 U. S., at 111-112. At the same time, the Court rejected a standard that would require the defendant to demonstrate that the evidence if disclosed probably would have resulted in acquittal. Id., at 111. The Court reasoned: “If the standard applied to the usual motion for a new trial based on newly discovered evidence were the same when the evidence was in the State’s possession as when it was found in a neutral source, there would be no special significance to the prosecutor’s obligation to serve the cause of justice.” Ibid. The standard of materiality applicable in the absence of a specific Brady request is therefore stricter than the harmless-error standard but more lenient to the defense than the newly-discovered-evidence standard.

The third situation identified by the Court in Agurs is where the defense makes a specific request and the prosecutor fails to disclose responsive evidence.¹¹ The Court did not define the standard of materiality applicable in this situation,¹² but suggested that the standard might be more lenient to the defense than in the situation in which the defense makes no request or only a general request. 427 U. S., at 106. The Court also noted: “When the prosecutor receives a specific and relevant request, the failure to make any response is seldom, if ever, excusable.” Ibid.

The Court has relied on and reformulated the Agurs standard for the materiality of undisclosed evidence in two subsequent cases arising outside the Brady context. In neither case did the Court’s discussion of the Agurs standard distinguish among the three situations described in Agurs. In United States v. Valenzuela-Bernal, 458 U. S. 858, 874 (1982), the Court held that due process is violated when testimony is made unavailable to the defense by Government deportation of witnesses “only if there is a reasonable likelihood that the testimony could have affected the judgment of the trier of fact.” And in Strickland v. Washington, 466 U. S. 668 (1984), the Court held that a new trial must be granted when evidence is not introduced because of the incompetence of counsel only if “there is a reasonable probability that, but for counsel’s unprofessional errors, the result of the proceeding would have been different.” Id., at 694.¹³ The Strickland Court defined a “reasonable probability” as “a probability sufficient to undermine confidence in the outcome.” Ibid.

We find the Strickland formulation of the Agurs test for materiality sufficiently flexible to cover the “no request,” “general request,” and “specific request” cases of prosecu-torial failure to disclose evidence favorable to the accused: The evidence 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. A “reasonable probability” is a probability sufficient to undermine confidence in the outcome.

The Government suggests that a materiality standard more favorable to the defendant reasonably might be adopted in specific request cases. See Brief for United States 31. The Government notes that an incomplete response to a specific request not only deprives the defense of certain evidence, but also has the effect of representing to the defense that the evidence does not exist. In reliance on this misleading representation, the defense might abandon lines of independent investigation, defenses, or trial strategies that it otherwise would have pursued. Ibid.

We agree that the prosecutor’s failure to respond fully to a Brady request may impair the adversary process in this manner. And the more specifically the defense requests certain evidence, thus putting the prosecutor on notice of its value, the more reasonable it is for the defense to assume from the nondisclosure that the evidence does not exist, and to make pretrial and trial decisions on the basis of this assumption. This possibility of impairment does not necessitate a different standard of materiality, however, for under the Strickland formulation 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. The reviewing court should assess the possibility that such effect might have occurred in light of the totality of the circumstances and with an awareness of the difficulty of reconstructing in a post-trial proceeding the course that the defense and the trial would have taken had the defense not been misled by the prosecutor’s incomplete response.

B

In the present case, we think that there is a significant likelihood that the prosecutor’s response to respondent’s discovery motion misleadingly induced defense counsel to believe that O’Connor and Mitchell could not be impeached on the basis of bias or interest arising from inducements offered by the Government. Defense counsel asked the prosecutor to disclose any inducements that had been made to witnesses, and the prosecutor failed to disclose that the possibility of a reward had been held out to O’Connor and Mitchell if the information they supplied led to “the accomplishment of the objective sought to be obtained ... to the satisfaction of [the Government].” App. 22 and 23. This possibility of a reward gave O’Connor and Mitchell a direct, personal stake in respondent’s conviction. The fact that the stake was not guaranteed through a promise or binding contract, but was expressly contingent on the Government’s satisfaction with the end result, served only to strengthen any incentive to testify falsely in order to secure a conviction. Moreover, the prosecutor disclosed affidavits that stated that O’Connor and Mitchell received no promises of reward in return for providing information in the affidavits implicating respondent in criminal activity. In fact, O’Connor and Mitchell signed the last of these affidavits the very day after they signed the ATF contracts. While the Government is technically correct that the blank contracts did not constitute a “promise of reward,” the natural effect of these affidavits would be misleadingly to induce defense counsel to believe that O’Connor and Mitchell provided the information in the affidavits, and ultimately their testimony at trial recounting the same information, without any “inducements.”

The District Court, nonetheless, found beyond a reasonable doubt that, had the information that the Government held out the possibility of reward to its witnesses been disclosed, the result of the criminal prosecution would not have been different. If this finding were sustained by the Court of Appeals, the information would be immaterial even under the standard of materiality applicable to the prosecutor’s knowing use of perjured testimony. Although the express holding of the Court of Appeals was that the nondisclosure in this case required automatic reversal, the Court of Appeals also stated that it “disagreed” with the District Court’s finding of harmless error. In particular, the Court of Appeals appears to have disagreed with the factual premise on which this finding expressly was based. The District Court reasoned that O’Connor’s and Mitchell’s testimony was exculpatory on the narcotics charges. The Court of Appeals, however, concluded, after reviewing the record, that O’Connor’s and Mitchell’s testimony was in fact inculpatory on those charges. 719 F. 2d, at 1464, n. 1. Accordingly, we reverse the judgment of the Court of Appeals and remand the case to that court for a determination whether there is a reasonable probability that, had the inducement offered by the Government to O’Connor and Mitchell been disclosed to the defense, the result of the trial would have been different.

It is so ordered.

Justice Powell took no part in the decision of this case.

1 In addition, ¶ 10(b) of the motion requested “[p]romises or representations made to any persons the government intends to call as witnesses at trial, including but not limited to promises of no prosecution, immunity, lesser sentence, etc.,” and ¶11 requested “[a]ll information which would establish the reliability of the Milwaukee Railroad Employees in this case, whose testimony formed the basis for the search warrant.” App. 18-19.

2 The Jencks Act, 18 U. S. C. § 3600, requires the prosecutor to disclose, after direct examination of a Government witness and on the defendant’s motion, any statement of the witness in the Government’s possession that relates to the subject matter of the witness’ testimony.

3 Brief for United States 3, quoting Memorandum of Points and Authorities in Support of Pet. for Habeas Corpus, CV80-3592-RJK(M) (CD Cal.) Exhibits 1-9.

4 The Assistant United States Attorney who prosecuted respondent stated in stipulated testimony that he had not known that the contracts existed and that he would have furnished them to respondent had he known of them. See App. to Pet. for Cert. 13a.

5 The Magistrate found, too, that ATF paid O’Connor and Mitchell, respectively, $90 and $80 in April and May 1977 before trial, but concluded that these payments were intended to reimburse O’Connor and Mitchell for expenses, and would not have provided a basis for impeaching O’Connor’s and Mitchell’s trial testimony. The District Court adopted this finding and conclusion. Id., at 7a, 13a.

6 By requiring the prosecutor to assist the defense in making its ease, the Brady rule represents a limited departure from a pure adversary model. The Court has recognized, however, that the prosecutor’s role transcends that of an adversary: he “is the representative not of an ordinary party to a controversy, but of a sovereignty . . . whose interest ... in a criminal prosecution is not that it shall win a case, but that justice shall be done.” Berger v. United States, 295 U. S. 78, 88 (1935). See Brady v. Maryland, 373 U. S., at 87-88.

7 See United States v. Agurs, 427 U. S. 97, 106, 111 (1976); Moore v. Illinois, 408 U. S. 786, 795 (1972). See also California v. Trombetta, 467 U. S. 479, 488, n. 8 (1984). An interpretation of Brady to create a broad, constitutionally required right of discovery “would entirely alter the character and balance of our present systems of criminal justice.” Giles v. Maryland, 386 U. S. 66, 117 (1967) (dissenting opinion). Furthermore, a rule that the prosecutor commits error by any failure to disclose evidence favorable to the accused, no matter how insignificant, would impose an impossible burden on the prosecutor and would undermine the interest in the finality of judgments.

8 In fact, the Brady rule has its roots in a series of eases dealing with convictions based on the prosecution’s knowing use of perjured testimony. In Mooney v. Holohan, 294 U. S. 103 (1935), the Court established the rule that the knowing use by a state prosecutor of perjured testimony to obtain a conviction and the deliberate suppression of evidence that would have impeached and refuted the testimony constitutes a denial of due process. The Court reasoned that “a deliberate deception of court and jury by the presentation of testimony known to be perjured” is inconsistent with “the rudimentary demands of justice.” Id., at 112. The Court reaffirmed this principle in broader terms in Pyle v. Kansas, 317 U. S. 213 (1942), where it held that allegations that the prosecutor had deliberately suppressed evidence favorable to the accused and had knowingly used perjured testimony were sufficient to charge a due process violation.

The Court again reaffirmed this principle in Napue v. Illinois, 360 U. S. 264 (1959). In Napue, the principal witness for the prosecution falsely testified that he had been promised no consideration for his testimony. The Court held that the knowing use of false testimony to obtain a conviction violates due process regardless of whether the prosecutor solicited the false testimony or merely allowed it to go uncorrected when it appeared. The Court explained that the principle that a State may not knowingly use false testimony to obtain a conviction — even false testimony that goes only to the credibility of the witness — is “implicit in any concept of ordered liberty.” Id., at 269. Finally, the Court held that it was not bound by the state court’s determination that the false testimony “could not in any reasonable likelihood have affected the judgment of the jury.” Id., at 271. The Court conducted its own independent examination of the record and concluded that the false testimony “may have had an effect on the outcome of the trial.” Id., at 272. Accordingly, the Court reversed the judgment of conviction.

9 The rule that a conviction obtained by the knowing use of perjured testimony must be set aside if there is any reasonable likelihood that the false testimony could have affected the jury’s verdict derives from Napue v. Illinois, 360 U. S., at 271. See n. 8, supra. See also Giglio v. United States, 405 U. S. 150, 154 (1972) (quoting Napue, 360 U. S., at 271). Napue antedated Chapman v. California, 386 U. S. 18 (1967), where the “harmless beyond a reasonable doubt” standard was established. The Court in Chapman noted that there was little, if any, difference between a rule formulated, as in Napue, in terms of “ ‘whether there is a reasonable possibility that the evidence complained of might have contributed to the conviction,’ ” and a rule “ ‘requiring the beneficiary of a constitutional error to prove beyond a reasonable doubt that the error complained of did not contribute to the verdict obtained.’” 386 U. S., at 24 (quoting Fahy v. Connecticut, 375 U. S. 85, 86-87 (1963)). It is therefore clear, as indeed the Government concedes, see Brief for United States 20, and 36-38, that this Court’s precedents indicate that the standard of review applicable to the knowing use of perjured testimony is equivalent to the Chapman harmless-error standard.

10 This is true only if the nondisclosure is treated as error subject to harmless-error review, and not if the nondisclosure is treated as error only if the evidence is material under a not “harmless beyond a reasonable doubt” standard.

11 The Court in Agurs identified Brady as a case in which specific information was requested by the defense. 427 U. S., at 106. The request in Brady was for the extrajudicial statements of Brady’s accomplice. See 373 U. S., at 84.

12 The Court in Agurs noted: “A fair analysis of the holding in Brady indicates that implicit in the requirement of materiality is a concern that the suppressed evidence might have affected the outcome of the trial.” 427 U. S., at 104. Since the Agurs Court identified Brady as a “specific request” case, see n. 11, supra, this language might be taken as indicating the standard of materiality applicable in such a case. It is clear, however, that the language merely explains the meaning of the term “materiality.” It does not establish a standard of materiality because it does not indicate what quantum of likelihood there must be that the undisclosed evidence would have affected the outcome.

13 In particular, the Court explained in Strickland: “When a defendant challenges a conviction, the question is whether there is a reasonable probability that, absent the errors, the factfinder would have had a reasonable doubt respecting guilt.” 466 U. S., at 695.