405 U.S. 150 (1972)
Giglio v. United States is a landmark Supreme Court case that extends the Brady v.
Does the prosecution's failure to disclose a promise of leniency to a key witness require a new trial under the principles established in Brady v. Maryland?
The suppression of evidence favorable to the accused violates due process where the evidence is material to guilt or punishment, including evidence that could impeach the credibility of a key government witness.
Yes, the Supreme Court held that the prosecution's failure to disclose the promise of leniency constituted a violation of Giglio's due process rights, and thus a new trial was warranted.
Giglio v. United States is significant for law students and practitioners because it refines the Brady doctrine by clarifying that material impeachment evidence falls under the prosecution's duty to disclose. This case highlights the broad obligation prosecutors have in ensuring defendants receive a fair trial by mandating disclosure of any evidence that may impact witness credibility. It underscores the prosecutor's role as a minister of justice, tasked with ensuring fairness over merely securing convictions.