turn King's/Queen's evidence

turn King's/Queen's evidence

To provide evidence in court against other parties involved in the crime for which one has been charged in order to receive a reduced sentence or to avoid prosecution altogether. (Either "King" or "Queen" is used depending on the current ruling monarch.) Primarily heard in UK. Many are speculating that the government aide taken into custody will agree to turn Queen's evidence against the Chancellor of the Exchequer.
See also: evidence, turn
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

turn King’s/Queen’s ˈevidence

(British English) (American English turn State’s ˈevidence) give information against other criminals in order to get a less severe punishment: One of the gang turned State’s evidence and identified at least three others involved in the fraud.
See also: evidence, turn
Farlex Partner Idioms Dictionary © Farlex 2017
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