From time to time, into the news burst accounts of regular people who commit crimes that seem totally out of character according to those who know them well. Lee Malvo, one of the D.C. snipers, was known to his friends and family as a smart, promising man. Steven, was a talented, young scientist with no criminal record. No one suspected he was capable of injuring another-until he was arrested for abducting a man, handcuffing him, and threatening to blow off his head with a pistol. What makes these otherwise stable and respected men and women commit crimes? Why do those who know them best...