Defendants argue that they are entitled to a new trial because the Government’s principal witness, Agent John Holm of the Division of Criminal Investigation of the Wisconsin Department of Justice, testified falsely at trial. We remand to the district court to make the appropriate findings under the standard articulated in
Napue v. Illinois,
The four co-defendants 1 in this case were convicted of conspiracy to purchase marijuana with intent to distribute. The *709 government agents had carried out a “reverse sting” operation in which the agents assumed the role of marijuana suppliers and sought to sell marijuana to the defendants.
Agent Holm testified at trial that on June 15, 1984, the date of the sting operation, he had not spoken to defendant Kaufmann before eleven that morning. At a post-trial hearing the district court found that Agent Holm’s testimony was false. Holm had in fact called Kaufmann three times before 11 a.m. on June 15. Kaufmann submitted an affidavit in which he states that during these phone calls he advised Holm that he was not interested in going ahead with the marijuana purchase and that Holm threatened him. The district court, however, explicitly declined to find whether Holm had perjured himself.
2
Tr.
3
at 85. Presumably she was only considering whether the defendants were entitled to a new trial under
Larrison v. United States,
On remand the district court should determine whether “the prosecution’s case includes perjured testimony and that the prosecution knew, or should have known, of the perjury.”
5
United States v. Agurs,
The principle that the prosecutor may not knowingly use false testimony applies even when the false testimony goes only to the
*710
credibility of the witness.
Bagley,
We think that false testimony that goes to the credibility of a witness is especially likely to be material when, as is the case for defendant Ostermeier, that witness’ testimony comprises the bulk of the evidence against him. We note that the precise content of the statements that, according to Holm, Ostermeier made at the site of the “sting” may have been important to the jury’s determination of Ostermeier’s guilt. Hence Holm’s credibility in this regard was important.
We remand to the district court to determine whether under the constitutional standard of Napue, the convictions of any of the three defendants who appealed should be set aside.
Notes
. Defendant Terrell Brown does not appeal.
. The district court judge did indicate that she would find it very difficult to believe that Holm forgot about the calls made before eleven. Tr. at 28-29.
. "Tr.” refers to the Transcript of Motion Hearing held before the Honorable Barbara Crabb on April 11, 1985.
. The government has not argued that the perjury issue was not adequately raised or that it is not properly before us or the district court.
. We note that although this court has not yet decided the issue,
see Holleman v. United States,
