state's evidence noun
Meaning:
turn state's evidence
US, law ◊If you are charged with a crime and you turn state's evidence, you agree to give information (such as the names of other criminals) to the court in order to reduce your own punishment.
▪ One of the gang members turned state's evidence [=(Brit) turned King's/Queen's evidence] and testified against the other members.
▪ One of the gang members turned state's evidence [=(Brit) turned King's/Queen's evidence] and testified against the other members.
