her attorney jim irvin called him culture with the news. >> here i am thinking, oh my gosh, could heck of my head, there is no way he could've did this. >> rick felt as though he had been sandbagged. >> i believed that if god saw fit to have me go home, i would go home. >> and that thought was about all he had left. faith in god and a good appellate lawyer. in this case, bob dudek. >> in my 22 or 23 years of being in an appellate defense attorney, rick gagnon was one of only about two, possibly three people that i genuinely believed was innocent. >> that certainty would mean exactly nothing to an appeals judge. unless bob and rick could come up with new evidence. then, in 2009, a year after his verdict, rick had an encounter in prison with yet another inmate. >> and it was all excited about something. >> authorities in tennessee, the prisoner told rick, had just arrested someone for a home invasion there. >> he told me he said they identified the killer. >> that man's name was bruce hill. when fact tennessee authorities ran his dna through the database, they had a match to the myster

right come out front now is professor at uc irvine who has done extensive studies on the brains of psychopathic killers and is the author of the psychopath inside. jim, i appreciate your time. when you look at this gunmen, do you say you're not surprised by this horrible, horrible act that occurred? tell me why. >> every new minute that comes out about the family points to something that looked pretty predictable and, you know, it is a fairly typical story. different recipes for disaster and creating a mass murderer or killer. probably the most likely one has to do with either psychopathy or sociopathy and part of the mix has to do in biological psychology the interaction of nature and nurture, which is between genes and environment. especially early environment. to create a psychopath, that happens between birth and two or three years old. sociopaths are created later during the growth period leading up to 10 or 12 years old. when i first looked at this, it was a 21-year-old man who was kind of a loner. you hear the story all the time. he could look a little strange but there is nothing about being eccentric at all. there is boo radley, but that is