Giglio v. United States concerns which type of information that prosecutors must disclose?

• A. Detective notes
• B. Exculpatory information
• C. Witness impeachment information
• D. Hearsay statements

Answer: (C)

Giglio v. United States centers on the prosecutor’s obligation to disclose information that could impeach a witness’s credibility. The decision holds that, beyond Brady’s exculpatory material, the defense must receive evidence that could be used to cast doubt on a witness’s truthfulness—such as prior inconsistent statements, deals or promises made to the witness, or any bias or financial interest affecting their testimony. This focus on credibility is why impeachment information is the correct answer. While detective notes or hearsay statements can matter in other contexts, Giglio specifically requires disclosure of information that could be used to undermine a witness’s reliability.