Kastigar v. United States
The Supreme Court ruled that the government can compel a witness to testify by granting 'use and derivative use' immunity — a promise not to use the testimony or anything found because of it — even without promising the witness can never be prosecuted for the crime itself.
The decision settles a long-running question about how much protection the Fifth Amendment requires before the government can force someone to talk, and it upholds the federal immunity statute Congress passed in 1970 as constitutionally sufficient.
“We hold that such immunity from use and derivative use is coextensive with the scope of the privilege against self-incrimination, and therefore is sufficient to compel testimony over a claim of the privilege.”
The Court's central holding on what kind of immunity the Fifth Amendment requires.
How it got here: A federal district court held the men in contempt for refusing to testify despite the immunity order; the Ninth Circuit affirmed, and the Supreme Court agreed to review the case.
The Case in Depth
What happened
Two men were subpoenaed to testify before a federal grand jury investigating alleged crimes. Expecting them to invoke their Fifth Amendment right against self-incrimination, prosecutors obtained a court order granting them immunity under a federal statute and directing them to answer. The men still refused to testify, arguing the immunity offered wasn't broad enough to justify overriding their constitutional privilege.
The question before the Court
Can the government force a reluctant witness to testify by promising only that the testimony and anything derived from it won't be used against him, instead of promising he can never be prosecuted for the underlying crime?
The Court's answer
No full immunity from prosecution is required — the Court ruled that immunity barring the use of compelled testimony and anything derived from it is enough to force a witness to testify, even though he could still be prosecuted later using genuinely independent evidence.
The Court reasoned that the Fifth Amendment only protects against being incriminated by one's own compelled words, not against prosecution itself. So a total ban on using the testimony or any leads it generates puts the witness in essentially the same position as if he had stayed silent, satisfying the Constitution. If the government later prosecutes, it must prove its evidence came entirely from sources unconnected to the compelled testimony.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Prosecutors and grand juries can compel reluctant witnesses — including people suspected of wrongdoing themselves — to testify using a narrower, cheaper form of immunity, while still being able to prosecute them later using evidence from independent sources. This makes it easier for the government to build cases in situations, like organized crime or corruption, where only insiders can supply useful testimony.
What changes now
The contempt judgment against the two men stands, and they remain subject to it unless they testify or the grand jury's term ends. More broadly, the ruling confirms that the 1970 federal immunity statute is constitutional, so prosecutors nationwide can continue using use-and-derivative-use immunity, rather than full transactional immunity, to compel testimony from unwilling witnesses in grand jury and other proceedings.
What this does not decide
The Court did not decide that immunized witnesses can never be prosecuted for related crimes — only that any later prosecution must rely entirely on evidence from sources independent of the compelled testimony, with the government bearing the burden of proving that independence.
Concurrences and dissents
How the Justices voted
Majority (1). Justice Powell (author).
Dissent (2). Justice Douglas (author).
Dissent — Justice Douglas
Justice Douglas argued that only full transactional immunity — a complete bar on prosecution for the matters testified about — satisfies the Fifth Amendment. He read Counselman v. Hitchcock as still good law, saw Murphy as addressing only a separate problem of testimony crossing between different governments, and warned that leads from compelled testimony can never be fully policed once given. Read the full dissent →
Dissent — Justice Marshall
Justice Marshall agreed a witness must be left in exactly the same position as if he had stayed silent, but argued that putting the burden of proof on prosecutors to show evidence is untainted is not a reliable enough guarantee, since only prosecutors know how their investigation actually developed. He would have required full transactional immunity because an immunity statute, unlike an exclusionary rule for police misconduct, authorizes the interrogation in advance and so demands an absolute guarantee against incrimination. Read the full dissent →
How the Court got there
The legal reasoning, step by step
- The Court first reaffirmed that immunity statutes in general can lawfully override the Fifth Amendment privilege, declining the witnesses' invitation to overrule earlier decisions upholding such statutes entirely.
- The Court then framed the real question as whether the specific immunity Congress had granted was 'coextensive' with the privilege — meaning it had to leave the witness no worse off than if he had simply stayed silent, though it did not need to give him more protection than that.
- Reviewing Counselman v. Hitchcock, the 1892 case that first struck down a federal immunity law, the Court explained that the earlier statute failed only because it let prosecutors use leads and evidence derived from the compelled testimony, not because anything short of full immunity from prosecution was constitutionally inadequate.
- Relying on Murphy v. Waterfront Comm'n, where the Court had required only a ban on using compelled testimony and its fruits across state and federal lines, the Court concluded that a total ban on using the testimony and everything derived from it gives a witness the same practical protection as invoking the privilege itself.
- The Court held that once a witness shows he testified under such an immunity grant, the government bears a heavy burden of proving any evidence it later uses against him came from a source completely independent of that compelled testimony.
- Applying this standard, the Court found the federal statute's total ban on both direct and indirect use of compelled testimony sufficient to replace the privilege, so the men's refusal to testify was not justified.
Doctrinal impact
Cases affected by this decision
Distinguishes Counselman v. Hitchcock (142 U. S. 547)
The Court said this 1892 case only struck down immunity that failed to bar use of evidence derived from testimony, not narrower immunity generally.
Reaffirms Brown v. Walker (161 U. S. 591)
The Court reaffirmed this decision upholding the constitutionality of immunity statutes generally.
Reaffirms Ullmann v. United States (350 U. S. 422)
The Court reaffirmed this decision upholding immunity statutes as part of constitutional law.
Reaffirms Murphy v. Waterfront Comm'n (378 U. S. 52)
The Court relied on this case's reasoning to hold use-and-derivative-use immunity constitutionally sufficient.