A debt-laden motivational speaker who appealed to a stranger to kill him was grimly determined to die, the convicted killer says in his first interview about the case.

In a piece set to air Saturday on CBS' "48 Hours Mystery," Kenneth Minor says he couldn't believe what he was hearing when Jeffrey Locker approached him on an East Harlem street in July 2009 and said he'd pay to die in a seeming robbery so his family could collect life insurance money.

Locker said, "'If you don't do it, someone else will. But this is getting done,'" Minor tells correspondent Richard Schlesinger in a prison interview.

Locker's family and the Manhattan district attorney's office had no immediate comment Friday.

Minor, 39, is serving a 20-years-to-life sentence after his April 2011 conviction in an unusual case that broached the concept of assisted suicide in the context of strangers staging a violent death. He didn't testify at his trial, though he had given his account in statements to police.

Both Minor and the Manhattan district attorney's office said Locker, 52, was looking to die. He was deep in financial trouble, partly because he'd invested in a $300 million Ponzi scheme.

Locker had researched funeral arrangements, had sent his wife an email explaining how to shield and distribute their assets "when I am gone" and had bought about $14 million in life insurance in his final months to add to $4 million he already had, investigators found.

Minor, meanwhile, had a drinking problem and was dealing drugs to make money, he says in the interview.

Prosecutors said Minor went beyond aiding suicide by stabbing Locker seven times in the self-help expert's car. Minor, who offered to plead guilty to the lesser charge of manslaughter, maintained that he only held a knife while Locker lunged into it and that he left the motivational speaker still alive — with "a smirk on his face," Minor tells "48 Hours Mystery."

"I just happened to be the building he jumped off," he says in the piece, helmed by executive producer Susan Zirinsky.

Minor's lawyer, Daniel J. Gotlin, said Friday he expects to file an appeal shortly.