The killings stopped when tough legislation was passed after Ms Guerin's death. Armed with new powers, garda broke up the drugs gang she had been investigating. It has big operations in Amsterdam. But the officers' success left a power vacuum. Would-be barons are vying again to take over parts of the highly lucrative trade, sparking violent confrontations.
Irish detectives say some murders are related to turf wars.
Other victims are accused of double-crosses. Police seized the drugs. Their boss, a notorious figure in Dublin's underworld, was furious. Murray was kidnapped, stripped, tortured and shot in the back of the head. Carey was also killed.