Opinion for the Court filed by Circuit Judge GARLAND.
The defendant in this criminal case contends that the government improperly denied his repeated requests for information to which he was entitled under
Brady v. Maryland,
*889 We need not accept either of these broad claims to resolve this case. The information defendant seeks would not merely be impeaching in the sense that it would weaken the credibility of his own witness. Rather, it would be exculpatory in the sense that it would be affirmatively favorable to his assertion of innocence. Accordingly, such information comes within the scope of the government’s Brady obligations. Because the government concedes that it has not searched to determine whether the requested information exists, we grant the defendant’s request that the case be remanded to the district- court. The government must first search to determine whether the information sought by defendant exists and, if it does, the district court must then determine whether that information is “material” within the meaning of Brady and its progeny.
I
In September 1996, an officer of the District of Columbia’s Metropolitan Police Department (MPD) applied for a warrant to search the home of John Doe 1 for a handgun and ammunition. The officer submitted an affidavit stating that an unidentified informant had observed the gun and ammunition there within the last 48 hours. The affidavit continued: “The source that provided this information has ... given information which has led to the arrests of several subjects for narcotics violations, the recovery of one assault weapon, the arrests of subjects wanted on warrants and the issuance of two search warrants.” Def.App. 11. A judge of the Superior Court of the District of Columbia granted the application.
The police executed the warrant the following morning. The officers found one semi-automatic handgun under the mattress in Doe’s basement bedroom, and a second gun, along with ammunition, in a shoebox under the basement stairwell. Doe was arrested and questioned. He denied the guns were his, and denied knowing that they were in the house. He said he had seen one of the guns in the possession of a friend, Thomas Jones, a couple of days earlier. Def.App., Tab A at 51. Doe’s girlfriend later testified that Doe and Jones had picked her up at the hospital the day before the search, and that after returning to Doe’s house, Jones had spent some time in the basement alone. Id., Tab D at 29-30.
Doe was charged with unlawful possession of a firearm and ammunition by a convicted felon, in violation of 18 U.S.C. § 922(g). In a pretrial motion filed in October 1996, Doe sought disclosure of the identity of the government’s informant. Pursuant to
Brady,
he also sought production of information concerning,
inter alia:
(1) “the amount of money ... paid to the source,” and whether it was “paid in exchange for information or otherwise”; (2) “other consideration provided to the source, including ... assistance in avoiding or minimizing harm from pending or threatened charges”; (3) “all benefits, promises of benefits, or statements that the source would not benefit absent cooperation ... in connection with this case”; (4) “the nature of assistance that the source has provided in the past”; and (5) “the source’s prior record, pending cases, and parole and probation status.” Def. App. 21. The court denied the request, ruling that defendant had not met the burden for piercing the government’s informant privilege set forth in
Roviaro v. United States,
Shortly before Doe’s trial was scheduled to begin, Thomas Jones called Doe’s attorney, told her that he had helpful informa *890 tion, and asked to meet with her. In January 1997, the attorney, her investigator, and Jones met in a restaurant parking lot. According to the investigator’s file memorandum, Jones told them that he was the government informant in Doe’s case and that “he wanted to clear his conscience.” Def.App. 29. He said that “he had a big gun and drug case in [District of Columbia] Superior Court and he had to work it off,” and identified three detectives with whom he was cooperating. Jones said the guns found in Doe’s apartment were his (Jones’). He said that the day before the execution of the search warrant, he and Doe had gone to pick up Doe’s girlfriend at the hospital. When they returned to the house, Jones continued, he “hid the guns, one under the mattress and one in a box under the stairs.” He did not tell Doe he was hiding the guns, and Doe did not know what he had done. Jones assured Doe’s attorney that he would testify at Doe’s trial. At the same time, he asked for assistance with his own legal problems: there was an outstanding bench warrant for his arrest, and Jones feared that the police would incarcerate him at the District of Columbia’s correctional facility at Lorton, Virginia. “I can’t go back to Lorton,” he said, “because I snitched on so many people.” Id.
Doe’s trial began a week later. In her opening statement, Doe’s attorney told the jury the evidence would show that Doe was innocent, and that Jones had planted the guns and ammunition in the house without Doe’s knowledge. Def.App., Tab C at 12. Thereafter, Doe’s attorney learned from the attorney in Jones’ Superior Court case that Jones intended to invoke his Fifth Amendment privilege against self-incrimination and would refuse to testify at Doe’s trial. The next morning, Doe’s attorney advised the court that, in order to get Jones’ prior statements before the jury, she planned to introduce them through the testimony of her investigator as statements against Jones’ penal interest, see Fed.R.Evid. 804(b)(3). Def. App., Tab D at 3-4.
At this point, the prosecutor questioned whether Jones really did have a Fifth Amendment privilege. After the court appointed a lawyer to advise Jones, Jones formally asserted his right not to testify. The prosecutor then asked “to speak with [Jones’ lawyer] over the luncheon recess to see if we can reach some sort of accommodation ... which would permit him [Jones] to testify.”
Id.
at 68,
After the luncheon recess, Jones agreed to testify and the government advised the court that it had agreed to make arrangements for his safety. Suspecting that Jones had become an adverse witness during the break, defense counsel again requested production of Jones’ “prior agreements with the government” and “sealed” case records. The court again put off decision, this time indicating it would not consider the issue until after Jones testified. Def.App., Tab E at 11.
Jones was then called to the witness stand by Doe’s counsel. Although he denied that he had told her the names of police officers with whom he was cooperating or that he was “working off’ a conviction in Superior Court, id. at 22, 27, Jones admitted that he had told her he was the confidential informant in Doe’s case, id. at 19. He also admitted to confessing that, while he was alone in the basement, he had planted the guns under the mattress and stairwell without Doe’s knowledge. Id. at 19-21.
On cross-examination by the prosecutor, Jones’ story changed dramatically. He *891 testified that his pre-trial statements to Doe’s counsel were lies. The guns, Jones said, were Doe’s. The day before the search, Doe had taken them out from underneath the mattress and stairwell to show to him. Id. at 33-38. Jones had lied about planting the weapons, he said, because “some dudes” had “threatened, if I didn’t call his lawyer, and tell the guns was mine some bodily harm would be done to me.” Id. at 27-28. After hearing Jones’ testimony, defense counsel asked the court to declare him a hostile witness and to permit her to cross-examine him. See Fed.R.Evid. 611(c). The court agreed. Def.App., Tab E at 39.
At the same time, however, the court rejected defendant’s renewed request for “information regarding [Jones’] sealed cases” and “agreements he’s made with the government regarding those cases.” Id. The court denied the request regarding the sealed cases saying, “I’m not going to at this late juncture make any effort to get those sealed records from the Superior Court.” Besides, the court said, any agreements reflected in the records of those cases “don’t have anything to do with this case anyway.” Id. at 42.
Persistently, but tactfully, defense counsel asked that the court at least direct the government to turn over its own agreements with Jones, noting “[t]hat doesn’t require anything from Superior Court.” Id. The prosecutor replied that there was no agreement in the instant case, but made no representation about agreements in other cases. 2 She did state, however, that “I think there may be some records that the police might have [although] I certainly don’t have anything right now.” More important, she continued, “I don’t think the government has an obligation to produce them to the defense in connection with a defense witness.” Id. The court agreed, ruling that the government was not required to produce records “in regard to a defense witness.” Id. at 43. The court advised defense counsel that she was free, however, to question Jones about any agreements he might have. Id.
Doe’s counsel proceeded to do so, but Jones denied being a “snitch,” id. at 50, said “I haven’t told on anybody,” id. at 53, and denied having “an agreement with the government,” id. at 57-58. Doe’s counsel did not impeach Jones or otherwise offer affirmative evidence of prior agreements or government cooperation. The jury convicted Doe of the offenses charged in the indictment, and the court sentenced him to 92 months in prison.
II
In
Brady v. Maryland,
the Supreme Court held that the Due Process Clause imposes upon the prosecution an obligation to disclose “evidence favorable to the accused ... where the evidence is material either to guilt or to punishment, irrespective of the good faith or bad faith of the prosecution.”
As the Supreme Court recently noted in
Strickler v. Greene,
courts have used the term
“Brady
violation” to cover a multitude of prosecutorial sins involving breach of “the broad obligation to disclose exculpatory evidence,” often called
“Brady
material.” - U.S. -, -,
It appears from the parties’ briefs that, contrary to Doe’s original understanding, the records of Jones’ Superior Court cases 3 were not sealed. Gov’t Br. at 36 n.21; Oral Arg. Tr. 14-15. Hence, Doe’s request for access to those records is effectively moot. His request for the disclosure of agreements between Jones and the government, however, remains very much alive. The government’s appellate brief advises us that Jones did “provid[e] information to the police as a paid special employee,” Gov’t Br. at 34 n.17, and its appendix discloses that Jones was required, as a condition of probation in one of his Superior Court cases, to cooperate with the police, see Gov’t App., Tab C at 3-4. At oral argument, the government also advised that “in candor with the court, it might involve the FBI, it might involve the DEA and other law enforcement agencies” as well. Oral Arg. Tr. at 29.
We therefore proceed to examine the arguments asserted by the government in support of its contention that, even if cooperation agreements exist, it has no
Brady
obligation to produce them. We conduct this examination de novo, since whether the government has breached its obligations under
Brady
is a question of law.
United States v. Cuffie, 80
F.3d 514, 517 (D.C.Cir.1996);
United States v. Lloyd,
A
At trial, the prosecutor argued and the court agreed that
Brady
did not apply because Jones was a defense witness. In response, the defendant points out that the Supreme Court’s description of the government’s
Brady
obligations encompasses
*893
evidence that can be used to impeach the credibility of a witness, and does not on its face distinguish between impeachment of a prosecution witness and impeachment of a witness for the defense.
4
The government replies that the Court’s references to impeachment in
Bagley
and
Giglio
involved prosecution witnesses (the same was true in
Strickler),
and that
Brady
and its progeny therefore do not require disclosure of impeachment evidence concerning a defense witness. “The Due Process Clause,” the government notes, “does not provide ‘a general constitutional right to discovery in a criminal case, and
Brady
did not create one.’” Gov’t Br. at 17 (quoting
Weatherford v. Bursey,
In the usual case there is a conceptual difference between the impeachment of a government witness and the impeachment of a defense witness. Evidence that impeaches the former is almost invariably “favorable” to the accused, because by making the government’s case less credible it enhances the defendant’s chances of acquittal. Evidence that impeaches a defense witness, by contrast, is not generally favorable to the accused; by reducing the credibility of the defendant’s own witness, such impeachment reduces the probability that he will obtain a not guilty verdict. It is ordinarily the prosecutor rather than defense counsel who wants to use the latter kind of evidence — although she may prefer to delay its use (and disclosure) until after the witness testifies, both to prevent tailoring of the testimony in expectation of the cross-examination and to employ the element of surprise to expose the witness’ mendacity.
But Doe’s is not the usual case involving impeachment of a defense witness. First, although it is true that defense counsel’s original plan was to put Jones on the stand as her own witness (either directly or through the testimony of the investigator), had things gone as planned she would have had no reason to impeach Jones’ credibility. It was only after Jones “flipped” and started testifying against Doe that defense counsel wanted to impeach him, hoping that evidence of a cooperation agreement would help her do so by showing that Jones lied when he said he had never “snitched” on anyone. Hence, even if we were to accept the proposition that only the impeachment of a government witness falls within
Brady,
by the time Jones flipped he had effectively become a government witness — as the court recognized by declaring him hostile.
See Kyles,
Second, and more important, the underlying reason Doe sought information about Jones’ relationship with the government was not to impeach Jones’ statement, but to use it as affirmative evidence of Doe’s own innocence. Indeed, if all had gone as planned, Doe would not have used evidence of a cooperation agreement to
impeach
Jones’ statement that he planted the guns, but rather to
corroborate
it by exposing his motive for doing so. With the testimony of Doe’s girlfriend that Jones had been alone in the basement, Doe had corroboration of Jones’ opportunity to plant the weapons. What he needed was evidence of motive, and any of several kinds of cooperation agreements might have provided it.
See Bagley,
Finally, as the government conceded at oral argument, in the circumstances of this case an agreement that gave Jones a motive to plant the guns would be
Brady
material even if Jones never appeared as a witness for either side. Oral Arg. Tr. at 21, 27;
see Kyles,
B
The potpourri of other objections to disclosure argued by the trial prosecutor and sustained by the trial court are also unpersuasive. The court’s original rejection of the defendant’s pretrial
Brady
motion correctly rested on the ground that, as matters then stood, the informant’s identity was confidential and “how the informer in this case might be helpful to the defen
*895
dant” was speculative. Def.App., Tab A at 83.
See United States
v.
Mangum,
Nor is there any basis for the rulings that production of the requested information was “premature,” first until it was clear Jones would testify, and then until after Jones actually did testify. Contrary to the prosecution’s contention, the information did not become relevant only after Jones changed his story, giving the defense reason to impeach him. As noted above, evidence of Jones’ motive was relevant independent of when or whether he testified. Similarly, we reject the government’s suggestion that ordering a
Brady
search before Jones testified would somehow have been inconsistent with our admonitions in
United States v. Marshall
(made with reference to Fed.R.Crim.P. 16), that “[t]o give rise to a disclosure obligation, the evidence’s materiality must, of course, be evident to a reasonable prosecutor,” and that the “prosecutor need not guess that evidence may become material as a consequence of a defendant’s not-yet-revealed strategic decisions.”
We also reject the government’s Cateh-22 rationale that once Jones did testify, it was by then too late to compel production of the information, since doing so would have required a continuance to gather the materials. The government protests that “in the midst of the trial” it should not have been required to “scamper” about searching for the requested evidence. Gov’t Br. at 32. But that problem could have been avoided had the government gathered the material earlier. In light of the defendant’s opening statement, it was no excuse the next morning that the prosecutor did not “have access to that information readily” and “would have to go back to my office and try to pull out old files and everything else.” Def.App., Tab D at 68. The same was true that afternoon, when she said, “I think there may be some records that the police might have [but] I certainly don’t have anything right now.” Id., Tab E at 42. And we do not understand the basis for the government’s argument that “appellant cannot credibly complain because he failed to assert a timely demand for this impeachment material.” Gov’t Br. at 40. To the contrary, defendant made his demands known early, often, insistently, and with specificity— only to be met with the government’s claims that they were first premature, and then too late. If by the time Jones testified the government still needed to “scamper” to collect the requested Brady material, it had no one to blame but itself. 7
*896
We find equally unfounded the argument that any agreements Jones may have had in his Superior Court cases “don’t have anything to do with this case.” Def.App., Tab E at 42. Defendant’s whole point was that Jones may have planted the gun in this case in order to “work off’ obligations that arose in those Superior Court cases. Hence, agreements in the other cases have everything to do with this case. Nor does it matter that agreements in other cases may have involved other prosecutors. The United States Attorney’s Office for the District of Columbia prosecutes cases in both the federal District Court and the local Superior Court, and the prosecutor is responsible (at a minimum) for all
Brady
information in the possession of that office.
See Giglio,
For a similar reason, we reject as irrelevant the contention that the requested records may have been in the possession of the Metropolitan Police Department, or the FBI or DEA, rather than the U.S. Attorney’s Office. As the Supreme Court held in
Kyles,
“[t]he individual prosecutor has a duty to learn of any favorable evidence known to the others acting on the government’s behalf in the case, including the police.”
C
Next, we consider the government’s appellate argument that it did not breach a disclosure obligation with respect to Jones’ cooperation agreements because that information was otherwise available through “reasonable pre-trial preparation by the defense.”
Xydas v. United States,
According to the U.S. Attorney, the first place the defendant should have turned for information about Jones’ agreements was Jones himself. Jones, the government points out, voluntarily contacted defense counsel and “was, for a time, cooperative with the defense.” Gov’t Br. at 32. “Since defense counsel had an opportunity to probe [Jones’] relationship with the government ... during their January ... conversation [in the restaurant parking lot], appellant cannot now use Brady as a vehicle to get answers to questions left unasked at that time.” Id. at 33. Again, we find this argument surprising. The *897 government’s position at trial was that virtually everything Jones .said to defense counsel at the January meeting was a lie, a position the government maintains on appeal. Oral Arg. Tr. at 26-27. Surely information obtained from a government-certified liar cannot substitute for information obtained from the government itself— particularly not when the defense was seeking information from a more trustworthy source in order to corroborate (or, as became necessary, impeach) that individual.
Second, the government contends that if Doe wanted to learn of Jones’ agreements with the MPD, he should have subpoenaed the involved officers themselves. Gov’t Br. at 33. This argument, too, is unpersuasive. As we have noted above, “the prosecutor is responsible for ‘any favorable evidence known to the others acting on the government’s behalf in the case, including the police,’ ”
Strickler,
- U.S. at - n. 12,
D
Finally, the government argues that Doe was not prejudiced by any nondisclosure that may have occurred because Doe’s attorney failed to impeach Jones with the information she did have in her possession. When Jones denied under oath that he had ever' informed on anyone else, Def.App., Tab E at 53 (“I haven’t told on anybody”), counsel could have contradicted him with the sworn affidavit attached to the search warrant application, Def.App. 12 (“The source has given information which has led to the arrests of several subjects”). She might also have tried to use a representation made by Jones’ attorney at the bench almost immediately after Jones made his denial. Id., Tab E at 61 (advising the court that there “was a stipulation of [Jones’] probation to assist the police on the street”). Defense counsel did not attempt to use either one.
There is no doubt that this- argument is relevant to the ultimate question of the materiality of the undisclosed evidence, that is, whether there was “a reasonable probability that, had the evidence been disclosed to the defense, the result of the proceeding would have been different.”
Strickler,
- U.S. at -,
On the other hand, the evidence that was available to Doe only indicated- that Jones had cooperated with the government, and perhaps that he had an agreement to do so. It did not disclose, at least not explicitly, the terms of any such agreement and whether they gave Jones a mo
*898
tive to plant the guns in Doe’s house. The latter would not have been the equivalent of what the defense already knew and, depending on the other facts in the case, may or may not have been material for
Brady
purposes.
See United States v. Smith,
Ill
The government concedes that it never conducted a full-fledged
Brady
search with respect to any agreements its various components may have had with Jones.
See
Oral Arg. Tr. at 23-24, 29-30, 38-39. For the reasons stated above, that failure constituted a breach of the government’s “duty to search” for
Brady
information.
Brooks,
This is the course we have followed in other cases,
see Brooks,
Notes
. Because this case remains under seal, the names of the defendant and the informant have been changed.
. In its brief before this court, the government states that it has "no reason to believe that any agreement existed between the United States Attorney’s Office and Mr. [Jones] with respect to his case in Superior Court.” Gov’t Br. at 34 n.17 (citing,
inter alia,
Gov’t App., Tabs A-F). We are confused by the government's statement since its citations, recently prepared transcripts of some of Jones’ Superior Court appearances, appear to refer to such an agreement.
See
Gov’t App., Tab C at 3 (statement by defense counsel that "[Jones] has been cooperating with providing information”; reply by Assistant U.S. Attorney that "we will need to ensure that the agreement is followed through”);
id.,
Tab E at 3 (statement by court that at sentencing ”[i]t was included in the representation by prosecution that the defendant was cooperating”).
But see id.,
Tab F at 7 (statement by prosecutor that "I have no information whether or not the defendant is cooperating”). It may be that the government regards the cooperation agreement referred to in these transcripts as one involving the police rather than the U.S. Attorney’s Office. If that is the distinction the government is drawing, it is of no moment to its obligations under
Brady. See Kyles v. Whitley,
. Jones has convictions for carrying a pistol without a license, attempted possession with intent to distribute cocaine, and attempted distribution of cocaine. Gov’t Br. at 6 n.7.
.
See Kyles,
.
Cf. Delaware v. Van Arsdall,
. There is, of course, nothing inappropriate about such agreements.
See United States v. Ramsey,
. Indeed, the government knew from the ‘ opening bell that it would at least have to prepare to conduct its own cross-examination of Jones.
See
Def.App., Tab B at 15 (listing defendant’s potential witnesses). Hence, it should not have needed the compulsion of
Brady
to learn all it could about him.
See
*896
Brooks,
