TheE4A was an intelligence-gathering unit within 'E' Department of theRoyal Ulster Constabulary, probably established in 1978.[1] It was primarily made up of police officers who conducted surveillance to be acted on byRUC Special Branch (E4C). E4A was supported by theHeadquarters Mobile Support Unit (now part ofSpecial Operations Branch) and targeted paramilitary groups, primarily theProvisional IRA.[2]