United States v. Mandujano

1976-05-19

Headline: Grand jury witnesses need not receive full Miranda warnings, and false grand jury testimony may be used in perjury prosecutions, making it harder for witnesses to avoid perjury charges based on Miranda errors.

Holding: The Court reversed, holding that Miranda warnings are not required for grand jury witnesses and that false sworn grand jury testimony need not be suppressed on that ground, so the Government may prosecute perjury.

Real World Impact:

Allows perjury prosecutions using grand jury testimony despite Miranda errors.
Supports prosecutors questioning witnesses without full Miranda-style warnings in grand juries.
Affirms that grand jury witnesses can consult counsel only outside the room.

Topics: grand jury rules, Miranda warnings, perjury prosecutions, witness rights

Summary

Background

Federal prosecutors investigating heroin trafficking in San Antonio learned of an undercover agent’s March 1973 encounter with a bartender who agreed to try to obtain heroin for the agent and accepted $650 but later returned the money without delivering drugs. About six weeks later the bartender was subpoenaed to testify before a special grand jury. At the start the prosecutor told him he must answer questions except those that would incriminate him, that he could consult a lawyer outside the room, and that false answers could lead to perjury charges. He denied recent sales but admitted past drug use and a prior conviction. He was later indicted for attempt to distribute heroin and for making false grand jury statements; the district court and the Fifth Circuit suppressed the grand jury testimony because full Miranda warnings were not given.

Reasoning

The Court addressed whether Miranda warnings are required for a grand jury witness who may be involved in the crimes under investigation and whether lack of Miranda requires suppression of false testimony used in a perjury prosecution. The majority reversed the court of appeals. It explained that Miranda was designed to guard against coercive custodial police interrogation, not grand jury proceedings conducted under judicial oversight. The Court held the volunteered warnings and oath given here were sufficient and that the Fifth Amendment does not let a witness avoid prosecution for deliberate false testimony simply because Miranda warnings were not provided.

Real world impact

The decision permits prosecutors to proceed with perjury charges based on sworn grand jury testimony even if full Miranda-style warnings were not given, so long as the situation lacks custodial interrogation characteristics. Grand jury procedures and prosecutor practices, including warnings and counsel access outside the room, will guide how investigations proceed. The case was reversed and remanded for further proceedings consistent with this opinion.

Dissents or concurrances

Justices Brennan (joined by Marshall) and Stewart concurred in the judgment. Brennan agreed perjury can be prosecuted but urged stronger protections for the Fifth Amendment and better safeguards about counsel and warnings for putative defendants; Stewart emphasized that the Fifth Amendment does not shield perjury.