6.36
56
The availability of a grant of immunity to witnesses before a Grand Jury is of vital
importance. Otherwise, potential witnesses who have not been granted immunity could frustrate the investigation by a Grand Jury by relying on the protection of the 5th Amendment to the US Constitution which guarantees privilege against self-incrimination, i.e. a person cannot be compelled to incriminate himself out of his own mouth. It is impossible for a person questioning such a witness to go behind his claim of privilege under the 5th Amendment. In a hearing before the Grand Jury, the power to grant immunity and the legal effect of the immunity granted is derived from the Organised Crime Act of 1970. That Act provides that testimony which a person granted such an immunity gives, or other information compelled under court order [or any information derived directly or indirectly from there], may not be used against such a witness in any criminal case, except a prosecution for perjury, giving a false statement or failing to comply with court order: 18 USC 2514. This does not prevent the testimony from being used in a civil suit or other action, e.g. dismissal from employment.
6.37
In practice, the targets of an investigation are not summoned to the jury, nor are they granted immunity. That is, the principle offenders are not summonsed to the jury nor are they given immunity. They will not usually know of the investigation. Witnesses are bound by the court from revealing their part in the proceedings. Immunity is employed with care with respect to those who are on the periphery of the crime complained of [e.g. prostitutes in a vice ring, a "fence" who has already been convicted].
6.38 When the case is sufficiently strong the prosecutor can invite an indictment. If the grand jury finds there is sufficient evidence it hands down an indictment. In both Federal and state jurisdiction the Attorney General is not bound to accept its recommendations but may file charges based on his assessment of the evidence.
6.39
Arrests are then made. The American police favour this procedure because it places them at a significant psychological advantage. A suspect knows he will stand trial in any event. The prosecution is not dependent, as it is in traditional forms of investigation, on an interview successfully eliciting admissions. Both the suspect and his counsel are made fully aware of the weight of evidence and this will often influence a confession or some other pursuit of leniency.