United States v. Calandra

Federal agents investigating Calandra (defendant) for illegal gambling seized loansharking records unrelated to the gambling warrant they were executing. A grand jury subpoenaed Calandra about the loansharking records; he invoked the Fifth Amendment and separately moved to suppress the evidence as obtained in violation of the Fourth Amendment.

Whether a witness may refuse to answer grand jury questions based on a belief that the underlying evidence was unlawfully obtained.