The witness who has been granted immunity has a shield against the consequences of self incrimination. The Federal immunity statute, the Witness Immunity Act of 1970, is discussed in detail, and the relationship between State immunity grants and Federal proceedings is explained. The process leading to the decision to seek immunity is discussed, including negotiations between the government prosecutor and defense counsel. Formal grants of immunity that confer statutory immunity upon a witness must come through a U.S. district court. The relationship between the witness and the government after the grant of immunity is detailed, and the uses of immunized testimony are discussed. Issues surrounding defense witness immunity have not yet been resolved by the Supreme Court. Many believe that if strong countervailing government interests are absent, courts should grant immunity to defense witnesses whose exculpatory testimony is necessary for an effective defense. 92 footnotes.