Few would disagree that Herbert Mullin, who thought he was saving California from the great earthquake by killing people, and Ed Gein, who was making chairs out of human skin, were entirely insane when they committed their acts. The question becomes more difficult with somebody like law student Ted Bundy, who killed twenty women while at the same time working as a suicide prevention counselor, or John Wayne Gacy, who escorted the first lady and then went home to sleep of thirty-three trussed-up corpses under his house. On one hand their crimes seem "insane," yet on the other hand, Bundy and Gacy knew exactly what they were doing. How insane were they?