John Kelly is a renowned criminal profiler, psychotherapist, and addiction specialist. In his 1992 paper, "The Alcohol, Drug, and Serial Killer Connection", he was the first theorist to label serial killing as an addiction. Kelly's profiling expertise was used in over 100 cases, including well-known cases such as the Green River Killer, the Molly Bish case, the Atlantic City Murders, the Woodsman of Worcester, and the Golden State Killer.