What makes some people murderers and others peaceful citizens? Oscar winner Alex Gibney's new true-crime documentary 'Crazy, Not Insane' examines the psychology of murderers based on research by forensic psychiatrist Dorothy Otnow Lewis. The true crime genre normally deals with the macabre crimes themselves, but Lewis asks why, not how. She is fascinated with the way in which the brain is affected by trauma, and she has dedicated her life to examining the inner lives of violent people. In her work, she has interviewed serial killers such as Ted Bundy, Arthur Shawcross and Joel Rifkin among others.