The defendants were subpoenaed to testify in front of the Waterfront Commission of New York Harbor. When they refused to answer questions asked of them, they were granted immunity from prosecution under the laws of both New Jersey and New York. They still refused to testify, contending that their answers might tend to incriminate them under federal law, to which the grant of immunity did not extend. They were then held in civil and criminal contempt.
Whether a state can compel a witness, whom it has immunized from prosecution under its laws, to give testimony which might then be used to convict him of a crime in federal court?
No. The defendant’s right to remain silent is a protection against both federal and state prosecution.
The Court looked to the policies and purposes of the Fifth Amendment right to be free from compulsory self- incrimination. “Most, if not all, of these policies and purposes are defeated when a witness ‘can be whipsawed into incriminating himself under both state and federal law even though’ the constitutional privilege against selfincrimination is applicable to each.” The Fifth Amendment right against compulsory self-incrimination protects a “state witness against incrimination under federal as well as state law and a federal witness against incrimination under state as well as federal law.” Accordingly, the Court held that “a state witness may not be compelled to give testimony which may be incriminating under federal law unless the compelled testimony and its fruits cannot be used in any manner by federal officials in connection with a criminal prosecution against him.”
378 U.S. 52, 84 S. Ct. 1594 (1964)