Giglio v. United States
Headline: Court orders a new trial after finding prosecutors failed to disclose a promise of no prosecution to the government's key witness, protecting defendants by requiring juries be told about witness incentives.
Holding: The Court held that the Government must provide a new trial because an assistant prosecutor promised the government's key witness he would not be prosecuted and that promise was not disclosed to the jury.
- Requires prosecutors to disclose any witness promises to the defense and jury.
- Gives defendants new trials when undisclosed witness deals affect credibility.
- Pushes prosecutor offices to adopt procedures ensuring case-wide communication.
Summary
Background
The defendant was convicted of passing forged money orders after a trial that relied almost entirely on testimony from a bank teller, Robert Taliento. During the trial the Government denied any promise of immunity to Taliento, and Taliento testified identifying the defendant. While an appeal was pending, an affidavit surfaced saying an assistant prosecutor had agreed Taliento would not be prosecuted if he testified for the Government.
Reasoning
The Court examined whether that undisclosed promise required a new trial under long‑standing due process rules about false or suppressed evidence. The Justices treated the prosecutor’s office as a single entity, concluding a promise by one assistant must be attributed to the Government. Because the prosecution’s case depended on Taliento’s credibility, any undisclosed agreement about future prosecution was material and the jury was entitled to know about it. The Court therefore held nondisclosure required a new trial, regardless of whether the failure to disclose was intentional or a mistake.
Real world impact
The decision reverses the conviction and sends the case back for a new trial. It makes clear that prosecutors are responsible for communicating any deals or promises made to witnesses to the lawyers trying the case and to the jury. Moving forward, large prosecutor offices may need rules and procedures to ensure everyone handling a case knows about witness agreements so juries can judge witness motives and credibility.
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