United States criminal law Responsibility for criminal law and criminal justice in the United States is shared between the states and the federal government. Parties to a crime The parties or participants in a crime include the principal and accessory. A principal is a ...

, a perjury trap is a form of prosecutorial strategy, which is sometimes claimed to be

prosecutorial misconduct In jurisprudence, prosecutorial misconduct or prosecutorial overreach is "an illegal act or failing to act, on the part of a prosecutor, especially an attempt to sway the jury to wrongly convict a defendant or to impose a harsher than appropri ...

in which a prosecutor calls a

witness In law, a witness is someone who has knowledge about a matter, whether they have sensed it or are testifying on another witnesses' behalf. In law a witness is someone who, either voluntarily or under compulsion, provides testimonial evidence, e ...

testify In law and in religion, testimony is a solemn attestation as to the truth of a matter. Etymology The words "testimony" and "testify" both derive from the Latin word ''testis'', referring to the notion of a disinterested third-party witness. ...

, typically before a

grand jury A grand jury is a jury—a group of citizens—empowered by law to conduct legal proceedings, investigate potential criminal conduct, and determine whether criminal charges should be brought. A grand jury may subpoena physical evidence or a per ...

, with the intent of coercing the witness into

perjury Perjury (also known as foreswearing) is the intentional act of swearing a false oath or falsifying an affirmation to tell the truth, whether spoken or in writing, concerning matters material to an official proceeding."Perjury The act or an inst ...

(intentional deceit under oath). Courts on

state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of State * ''The State'' (newspaper), a daily newspaper in Columbia, South Carolina, United States * '' Our ...

and federal levels almost never recognize such as inappropriate, as doing so would in essence, condone perjury. As an example, suppose that a person committed a crime for which they were never prosecuted, but the

statute of limitations A statute of limitations, known in civil law systems as a prescriptive period, is a law passed by a legislative body to set the maximum time after an event within which legal proceedings may be initiated. ("Time for commencing proceedings") In mo ...

on that crime has expired. A prosecutor could set a perjury trap for them by calling them as a witness before a grand jury in a case about a different crime, and ask them about the expired crime. If the witness lies about the expired crime, that would be perjury—a new crime, which could then be prosecuted. Prosecution for perjury elicited in this manner violates

due process Due process of law is application by state of all legal rules and principles pertaining to the case so all legal rights that are owed to the person are respected. Due process balances the power of law of the land and protects the individual per ...

of law, since the investigatory powers of the grand jury are exploited to reach beyond their legal limits. It has been argued by legal scholars whether it constitutes a form of

entrapment Entrapment is a practice in which a law enforcement agent or agent of the state induces a person to commit a "crime" that the person would have otherwise been unlikely or unwilling to commit.''Sloane'' (1990) 49 A Crim R 270. See also agent provo ...

. Claims of a perjury trap are common when perjury charges result from testimony before a

, but are rarely proven. No

US federal court The federal judiciary of the United States is one of the three branches of the federal government of the United States organized under the United States Constitution and laws of the federal government. The U.S. federal judiciary consists primaril ...

has ever accepted a motion to dismiss because of claimed perjury trap. The defense is extremely difficult, because the question that elicited the perjured testimony must be immaterial to the case in which it was asked, and courts construe very broadly what questions count as material to a case.

References

Perjury Legal terminology Abuse of the legal system {{Law-stub