Prime Suspect

Will New Evidence Give Marty Tankleff A Second Chance?

This story originally aired July 15, 2006. It was updated on Aug. 8, 2007.

Marty Tankleff was only 18 when he was convicted of murdering his parents in 1990. Since then, he has lived in a remote New York state prison, a far cry from his childhood, spent in a sprawling Long Island waterfront home.

But now, after years behind bars, Tankleff believes freedom may be within his reach. Correspondent Erin Moriarty reports.

Joe Guarascio is about to do something that he believes could put his life at risk: walk into a courtroom and accuse his own father of murder.

"I just decided the truth needs to be heard, I need to do the right thing. I need to step up and be a man," says Joe.

He is taking this extraordinary measure to help free a man he doesn't even know: Marty, who was arrested for murder in 1988 when he was the same age as Joe, only 17 years old.

Joe says his father once told him that he in fact had committed the crime.

Marty, at nearly 35, has spent most of the past 16 years in a remote New York state prison for two murders he insists he didn't commit.

Before the murders, Marty spent is childhood in the lap of luxury. "It was a wonderful childhood," he recalls.

Seymour and Arlene Tankleff were unable to have children of their own, so they adopted Marty as a baby.

Marty says his mom was great and that 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," he explains.

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," says Marty.

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 a lot of money.

"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 Tankleff'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. Then, Marty says, he searched for his mother and found her dead on her bedroom flood.