The word “psychopath” conjures up movie images of brutal, inexplicable violence: Jack Nicholson chasing his family with an ax in The Shining or Anthony Hopkins as Hannibal Lecter, his face locked into an armored mask to keep him from biting people to death. But real life offers another set of images, that of killers making nice: Ted Bundy as law student and aide to the governor of Washington State, and John Wayne Gacy as the Junior Chamber of Commerce’s “Man of the Year.” Psychopaths are likable guys when they want to be.