[This story was first broadcast on Jan. 26, 2008. It was updated on Aug. 8, 2008.]
Marty Tankleff was only a teenager when he was convicted of murdering his parents. He spent more than half his life in remote New York state prisons, a far cry from his privileged childhood on New York's Long Island.
Marty initially confessed, but quickly recanted. He fought for years for his innocence, especially as new witnesses surfaced that could potentially exonerate him.
Correspondent Erin Moriarty, who has covered this case for years, reports on this rollercoaster of a legal case.
Marty had just turned 17 when he was arrested for the murder of his parents, Seymour and Arlene. He has spent his entire adult life in remote upstate New York prisons.
It's a far cry from Marty's childhood, spent in the lap of luxury in a sprawling Long Island waterfront home. Seymour and Arlene were unable to have children of their own, so they adopted Marty as a baby.
Marty says his mom was "great." "She adored me and I adored her. We were the best of friends," he remembers.
He was also close to his father. "My father had a poor childhood. When I became a teenager, he had money, so he lived vicariously through me," says Marty, who admits he was spoiled by his parents.
Seymour, a savvy and tough entrepreneur, was grooming Marty to follow in his footsteps. "I wanted to be a businessman. So I enjoyed being involved in all of that," Marty explains.
Marty says he knew everything about his father's businesses, including the trouble his dad was having with a partner in a bagel shop, Jerry Steuerman, who owed him around half a million dollars. "The friendship had dissipated. They essentially became enemy business partners," Marty says.
Despite the tension between Seymour and Jerry Steuerman, both men continued to play in a weekly poker game. And on Sept. 6, 1988, it was Marty's father's turn be host. The game lasted into the wee hours and Steuerman was the last to leave. The next morning, Marty says, he woke to find his father near death.
Marty called 911. "I just remember the woman yelling back at me saying 'Calm down, calm down.' She gave me some instructions," he remembers.
Then, Marty says, he searched for his mother. He found her dead on her bedroom floor.
James McCready, the lead detective, now retired, arrived an hour later, and remembers the scene as "very brutal."
Seymour, bludgeoned and stabbed but still alive, had been rushed to the hospital; Arlene's body still lay in her room. "She was nearly decapitated," McCready remembers. "And it appeared to me that she had struggled with whoever had assaulted her."
McCready, a homicide cop for ten years, saw no sign of forced entry and was immediately bothered by Marty's appearance. "He was sitting as calm as calm could be, with his hands clasped like this," McCready recalls.
Asked what he would have expected for Marty to be doing, McCready says, "Oh, I think he would have been crying, I think he would have been shaken, been very upset."
What impression did Marty get from McCready? "I felt that they were trying to help me and I was trying to help them," he says.
But McCready says he "could see" Marty was lying. "I get a feeling, it's not so much the way, what is said. It's the way in which it's said."
Marty volunteered his suspicions that Steuerman, his father's partner, was somehow involved and Marty agreed to talk more about that at police headquarters. But in fact McCready thought he already had his man.
Why would Marty kill his parents? McCready has a theory: greed.
Seventeen-year-old Marty sat alone with McCready and his partner, without a lawyer, in a small windowless room for hours, where the detectives questioned him. "It was the constant barrage that 'Marty, we know you did it, everything will be ok, just tell us you did it. We know you did it.' And the on and on and on questioning. Over and over," he remembers.
Then, McCready did something that would change everything: he left the room, pretended to talk on the phone, and came back with news about Seymour. The detective told Marty his father had come out of his coma and had implicated Marty in the murder.
But McCready admits he lied to Marty, and that Seymour's statement never happened. Asked if that's all right to do, McCready says, "the United States Supreme Court says it is."
Marty begged to take a polygraph, but the detectives refused.
"So you're better at telling whether someone is lying?" Moriarty asks McCready.
"I? I think I'm better than the polygraph machine," the detective replies.
McCready's scheme worked. Marty began to wonder if he blacked out and in fact had attacked his parents. Finally, he told the police what they wanted to hear.
McCready began to prepare a written statement. Although Marty - who didn't write it himself - never signed it, and almost immediately recanted, the detectives had enough. Marty was arrested and charged with murder.