Supergrass (informant)

The term "supergrass" refered to arrested IRA members who divulged the identities of their compatriots to the Royal Ulster Constabulary in exchange for immunity from prosecution, essentially, an informer. The 'Supergrass phenomenon' in Northern Ireland began with the arrest of Christopher Black in Northern Ireland in 1981. After securing assurances that he would have protection from prosecution, Black gave statements which lead to 38 arrests. By the end of the following year, 25 more 'supergrasses' had surfaced, contributing to the arrests of over 600 hundred people.

(For more, see The Crowned Harp: Policing Northern Ireland by Graham Ellison and Jim Smyth (2000))