Whether a witness before a grand jury may refuse to answer questions on the ground that they are based on evidence obtained through an unlawful search and seizure.
Holding
No. The Fourth Amendment exclusionary rule does not permit a grand-jury witness to refuse to answer questions derived from illegally seized evidence.
Reasoning
The grand jury has a historically broad investigative role. It determines whether probable cause exists to believe a crime has been committed and whether charges should be brought, rather than adjudicating guilt. To carry out that role, it may investigate widely and generally operates without the trial-level evidentiary and procedural restrictions that govern adversarial criminal proceedings.
A grand-jury witness ordinarily has a duty to provide evidence. A witness may assert a recognized privilege, including the Fifth Amendment privilege against self-incrimination unless valid immunity is provided, and may challenge an unreasonable subpoena. But a witness generally may not object that questions are incompetent, irrelevant, or based on information the witness believes the Government obtained unlawfully.
The exclusionary rule is not a personal constitutional right that automatically bars every governmental use of unlawfully obtained evidence. It is a judicially created remedy whose principal purpose is to deter future Fourth Amendment violations. The Court therefore applies the rule where its deterrent benefits justify its costs to other important institutional interests.
Extending the rule to grand-jury questioning would substantially disrupt the grand jury’s work. It would require suppression hearings during investigations, delay proceedings, and turn grand-jury inquiries into preliminary trials over issues that ordinarily belong at a criminal trial. That interference could frustrate investigations and impair the grand jury’s ability to follow leads promptly and thoroughly.
The added deterrent value of exclusion at the grand-jury stage was speculative and slight. Police already have a strong incentive to comply with the Fourth Amendment because illegally seized evidence generally cannot be used against the search victim at a later criminal trial. Prosecutors ordinarily will not seek an indictment when the evidence needed for conviction will be inadmissible at trial.
Silverthorne Lumber Co. v. United States did not compel a different result. There, the subpoena followed indictments and a prior judicial determination that the documents had been unlawfully seized; the practical effect was to prevent use in an already authorized prosecution. Calandra, by contrast, had not been indicted, and allowing his claim would interrupt an ongoing grand-jury investigation.