perjury trap doctrine
perjury-trap doctrine. The principle that a perjury indictment against a person must be dismissed if the prosecution secures it by calling that person as a grand-jury witness in an effort to obtain evidence for a perjury charge, esp. when the person’s testimony does not relate to issues material to the ongoing grand-jury investigation. [Cases: Perjury 10, 15. C.J.S. Perjury §§ 11, 21, 25–33.]