Kastigar v. United States 406 U.S. 441, 92 S.Ct. 1653, 32 L.Ed.2d 212 (1972)
A prosecutor wanted Kastigar
and Stewart to testify before a grand jury. However, the required
testimony would implicate them in a crime. Therefore the prosecutor
granted the two immunity and then
ordered them to testify.
Kastigar and Stewart refused
to testify, and were arrested and charged with contempt. They appealed.
Kastigar and Stewart argued
that the subpoena violated their 5th Amendment right against self-incrimination because the
grant of immunity did not include transactional immunity.
Transactional immunity means that you are immune from prosecution
for any offense to which the compelled testimony might relate, no matter
what other evidence there is.
For plain old regular immunity
from use and derivative use (like
being offered here), if charges are later filed against the witness, the
burden is on the prosecution to show that the information came from a
completely independent source.
In addition, Kastigar and
Stewart argued that being forced to testify (and possibly implicate
oneself in a crime) without being allowed to have a lawyer in the
courtroom was a violation of the 6th Amendmentright to counsel.
The Appellate Court affirmed.
Kastigar and Stewart appealed.
The US Supreme Court affirmed.
The US Supreme Court found
that a witness "who invokes the 5th Amendment privilege against compulsory
self-incrimination" can be compelled to testify if given immunity
"as such immunity from use and derivative use is coextensive with
the scope of the privilege and is sufficient to compel testimony over a
claim of privilege."
While transactional
immunity offers broader protection,
it is not constitutionally required.
The Court noted that a grant
of immunity is not a pardon nor an
amnesty from the crime. The government should still be allowed to
prosecute using evidence from legitimate independent sources. The only
thing that the 5th Amendment prohibits is
compelled self-incrimination, and immunity from use and derivative use satisfies that prohibition.
Transactional immunity puts the defendant in a better position then they would be if they did not
testify.
In most cases, derivative
use immunity is the functional
equivalent of transactional immunity. The 'derivative use' is important because if you admit that you
did the crime then the police would be tempted to look extra hard to find
independent evidence of your guilt.
See Murphy v. Waterfront
Commission of New York (378 U.S. 52
(1964)).