Between the Lines S01E11 - Nothing Personal

Joey Pearce, a young man, is found hanging in his cell at St. Helen's nick. The arresting officer, DI Gordon, is called to help revive the boy, but he is dead. Clark is called out and starts investigating; one by one Clark interviews everyone in the custody suite. Pearce had been arrested with another man, Dilly, a known dealer, in possession of dealer quantities of crack.