Giglio v. United States

Petitioner filed a motion for a new trial on the basis of newly discovered evidence contending that the Government failed to disclose an alleged promise of leniency made to its key witness in return for his testimony. At a hearing on this motion, the Assistant United States Attorney who presented the case to the grand jury admitted that he promised the witness that he would not be prosecuted if he testified before the grand jury and at trial. The Assistant who tried the case was unaware of the promise.

Held: Neither the Assistant's lack of authority nor his failure to inform his superiors and associates is controlling, and the prosecution's duty to present all material evidence to the jury was not fulfilled and constitutes a violation of due process requiring a new trial. Pp. 153-155.

Reversed and remanded.

BURGER, C.J., delivered the opinion of the Court, in which all Members joined except POWELL and REHNQUIST, JJ., who took no part in the consideration or decision of the case.

James M. La Rossa argued the cause and filed a brief for petitioner.

Harry R. Sachse argued the cause for the United States. On the brief were Solicitor General Griswold, Assistant Attorney General Wilson, Jerome M. Feit, and Beatrice Rosenberg.