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State's Evidence

A colloquial term for testimony given by an ACCOMPLICE or joint participant in the commission of a crime, subject to an agreement that the person will be granted IMMUNITY from prosecution if she voluntarily, completely, and fairly discloses her own guilt as well as that of the other participants.

State's evidence is slang for testimony given by criminal defendants to prosecutors about other alleged criminals. A criminal defendant may agree to provide assistance to prosecutors in exchange for an agreement from the prosecutor that he will not be prosecuted. This agreement is commonly called turning state's evidence.

A criminal defendant who turns state's evidence may be offered a plea bargain or may have all criminal charges against him dismissed, depending on the nature of the case against the testifying defendant and the largesse of the prosecutor. A prosecutor may give a testifying defendant full immunity, which means the defendant cannot be charged with any crime related to the testimony he provides. A lesser form of immunity is called use immunity. Use immunity means that the prosecutor agrees only that she will not use any of the testimony given by the testifying defendant in any subsequent prosecution of that defendant.

Turning state's evidence plays an important role in the criminal justice system, in large part because the system is overwhelmed by criminal prosecutions. To ease the caseload, prosecutors regularly exercise their power to offer to drop or decrease charges in exchange for a plea of guilty. Another by-product of the backlog of cases is that prosecutors are most concerned with successfully prosecuting the most dangerous criminals. For these reasons, prosecutors commonly ask petty criminal defendants who have access to other alleged criminals to obtain evidence from the criminals.

For instance, assume that a person who has been arrested for possession of marijuana is willing to work with law enforcement to obtain inculpatory evidence from the dealer of the marijuana. To do so, the defendant would return to the dealer after the arrest, purchase marijuana in a transaction monitored by law enforcement, and then give the marijuana to the authorities as evidence.

A prosecutor may drop charges against a petty criminal in exchange for substantial assistance to law enforcement authorities in the prosecution of more dangerous criminals. Alternatively, a prosecutor may offer a plea bargain and ask the court to impose a sentence that is less severe than the sentence normally imposed for the crime.

State and federal sentencing statutes govern the effect of providing substantial assistance. Courts usually follow the recommendations of the prosecutor, but they are not obliged to do so. On the federal level, for example, section 5K1.1 of the Federal Sentencing Guidelines states that a court may evaluate the significance and usefulness of the assistance rendered by the defendant, the truthfulness and reliability of the defendant, the nature of the defendant's assistance, and other factors in determining whether to impose a relatively light sentence.


Bloom, Robert M. 2002. Ratting: The Use and Abuse of Informants in the American Justice System. Westport, Conn.: Praeger.

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