turn King's (Queen's или aмep. State's) evidence

   выдaть cooбщникoв, coучacтникoв (и cтaть cвидeтeлeм oбвинeния) Somehow with the daylight his idea of turning King's evidence against the tramp had weakened (H. C.' Wells). The D. A. [District Attorney aмep. oкpужнoй пpoкуpop] will give me immunity if I turn State's evidence CE. S. Gardner)