At California State University Dr Eric W Hickey devised a model showing the development of the murderous personality, based on research into more than 200 cases of serial murder. These findings are applied to the case of Jeffrey Dahmer, who between 1978 and 1991 killed 17 young men. Shows conversations between Dahmer and his forensic psychologist and footage of the trial. Behavioural psychologists and criminologists explain how Dahmer and other serial killers such as Ted Bundy, Peter Sutcliffe and John Wayne Casey came to kill.—Channel Four