DOING A CONROY

DOING A CONROY is a British slang term for an informant who turns King's evidence, often in return for protection and immunity from prosecution. In the British criminal world, police informants have been called "CONROYS" since the late 1930s, and the "doing a CONROY" prefix was coined by journalists in the 1980s 1990s to describe those who witnessed against fellow criminals in a series of high-profile mass trials in the North-east of England at the time

HE GOT ARRESTED & GAVE EVIDENCE AGAINST HIS CO ACCUSED
He "did a conroy" he is DOING A CONROY