A criminal turns state's evidence by admitting guilt and testifying as a witness (also called crown witness) for the state against his/her associate(s) or accomplice(s), often in exchange for leniency in sentencing or immunity from prosecution. The testimony of a witness who testifies against co-conspirator(s) may be important evidence.
In the United Kingdom and the Commonwealth realms, the term is to turn Queen's or King's evidence, depending on the gender of the reigning monarch. The term "turning approver" or "turn king's approver" was also historically used, and is still used in India and Pakistan; an approver "not only admitted his own guilt to a crime but also incriminated his accomplices both past and present" in exchange for avoiding a death sentence (and obtaining a lesser penalty, such as life imprisonment or abjuration of the realm) or improving prison conditions.
Witnesses who have turned state's evidence have been important in organized crime cases in the United States, such as those against the American Mafia. The first mafiosi who turned state's evidence, such as Joseph Valachi and Jimmy Fratianno, did so in response to threats on their life from Mafia associates; later cooperators were motivated to cooperate in order to avoid heavy sentences, such as those provided for under the RICO Act. Some who turned state's evidence were permitted to participate in the Witness Security Program (WITSEC). Among the highest-ranking Mafia members to ever turn state's evidence was Salvatore Gravano ("Sammy the Bull"), an underboss of the Gambino crime family who pleaded guilty to 19 murders and agreed to testify against family boss John Gotti. (Gravano was sentenced to 20 years; Gotti was sentenced to life imprisonment in 1992). Joseph Massino was also the first boss of one of the Five Families in New York City to turn state's evidence.
- "Good practices for the protection of witnesses in criminal proceedings involving organized crime" (PDF). United Nations. 2008. p. 19. Retrieved 9 October 2020.
- Pomeroy, John Norton (1876). "State's Evidence". In Barnard, Frederick A. P. (ed.). Johnson's new universal cyclopædia a scientific and popular treasury of useful knowledge. New York; Pittsburgh, Pa.: A. J. Johnson & son. p. 495‒496.
- Howard Abadinsky, Organized Crime (9th ed: Cengage Learning, 2010), p. 368.
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- Mark D. West, Secrets, Sex, and Spectacle: The Rules of Scandal in Japan and the United States (University of Chicago Press, 2006), p. 36.
- Chris Strohm, Mueller Uses Classic Prosecution Playbook Despite Trump Warnings, Bloomberg News (August 23, 2017).
- Evan Thomas, The Man to See (Touchstone, 1991), p. 407.
- Robert J. Kelly, Ko-lin Chin, Rufus Schatzberg, "Without Fear of Retribution: The Witness Security Program" in Handbook of Organized Crime in the United States (Greenwood, 1994), p. 499.
- Michael D. Lyman, Practical Drug Enforcement (3rd ed.: CRC Press, 2007), p. 85.
- Raab, p. 688.
- Robert D. Behn, Rethinking Democratic Accountability (Brookings Institution Press, 2001), pp. 47–48.
|Wikisource has the text of the 1905 New International Encyclopedia article State's Evidence.|
- H. Lloyd King, Jr., Why Prosecutors are Permitted to Offer Witness Inducements: A Matter of Constitutional Authority, 29 Stetson L. Rev. 155 (1999).