Giglio v. United States, 405 U.S. 150 (1972)

In Giglio, the Supreme Court held that the prosecution violates the Fourteenth Amendment due process clause when it fails to disclose exculpatory evidence to the defense, even if the individual prosecutors are unaware of the undisclosed information.

The prosecution’s star witness at Giglio’s forgery trial was his alleged coconspirator, Taliento. Taliento testified that the prosecution had not promised him immunity from prosecution in exchange for his testimony. However, after Giglio’s conviction, the defense learned that another prosecutor had indeed promised Taliento that he would not be prosecuted.

Giglio’s motion for a new trial was denied, but the U.S. Supreme Court unanimously reversed. The Court held that the government’s failure to disclose its promise to Taliento violated Giglio’s due process right, established in Brady v. Maryland, 373 U.S. 83 (1963), to receive exculpatory information from the prosecution in advance of the trial. In addition, as in Napue v. Illinois, 360 U.S. 264 (1959), the undisclosed information proved that the government violated Giglio’s due process rights by presenting testimony from Taliento that it knew to be false. Finally, the Court stressed that it was irrelevant that the prosecutor who tried Giglio did not personally know of the promise to Taliento because the prosecution has a duty, as an entity, to disclose exculpatory information.

Giglio is therefore an important case because it establishes that a prosecutor’s duty to disclose exculpatory evidence extends beyond information that he or she personally possesses. Instead, a prosecutor has a duty to find and disclose any exculpatory information in the hands of the government.

DAVID A. MORAN

References and Further Reading

• Imwinkelried, Edwin, and Norman Garland. Exculpatory Evidence, 2nd ed. Charlottesville, VA: Michie Publications, 1996.
• Stacy, Tom, The Search for Truth in Constitutional Criminal Procedure, Columbia Law Review 91 (1991): 1369.

Cases and Statutes Cited

• Brady v. Maryland, 373 U.S. 83 (1963)
• Napue v. Illinois, 360 U.S. 264 (1959)

See also Brady v. Maryland, 373 U.S. 83 (1963); Due Process; Fourteenth Amendment; Napue v. Illinois, 360 U.S. 264 (1959)