The four suspects, with the aid of a cement truck blocking the way, escaped the Exchange on motorcycles, taking hostages.In the shells was an experimental chemical weapon, a binary nerve agent causing symptoms of late-stage cerebral palsy - "the most massive attack in the history of chemical warfare.The gritty crime film opens appropriately with a much-celebrated, giant closeup of a.38 gun lying on a living room desk.The hand of a man seated at the desk reaches for the gun and removes the weapon from view.After a single gunshot to his temple - a sudden suicide - the man falls forward into camera view and slumps over he desk.(Walsh had also directed Cagney in two other films:Strawberry Blonde (1941)andA Lion Is In the Streets (1953).