 He was imprisoned in Long Kesh, where he held the position of camp adjutant.In the late 1970s and early 1980s he was part of a four-man active service unit, along with Joe Doherty and Angelo Fusco, nicknamed the "M60 gang" due to their use of an M60 general purpose machine gun.On 9 April 1980 the unit lured the Royal Ulster Constabulary (RUC) into an ambush on Stewartstown Road, killing Constable Stephen Magill and wounding two others.