Volunteers

S4 E2: Is a bloodied and bruised homeless man a victim of the streets - or the residents? Detectives discover a large amount of cash in the victim's pocket, which rules out robbery as a motive. Upon questioning locals, they learn of a neighborhood watch group called The Block Association who say they only wanted the transient committed to a hospital, not dead. It is soon revealed that the homeless man had mugged a local resident moments before he himself was attacked - which points the case in a new direction.