The man in the black car was approaching people on an East Harlem street corner, asking to buy a gun and saying he “wanted to do a Kevorkian.” Kenneth Minor said he shooed the man away, but he returned with a more outrageous request:

“I want you to shoot me.”

So began the bizarre tale that Mr. Minor told the police two summers ago after the man, Jeffrey Locker, was found bloodied, bound and dead in his car, while Mr. Minor was caught on tape using Mr. Locker’s A.T.M. card.

The A.T.M. card, Mr. Minor explained, was the payment Mr. Locker, a motivational speaker from Long Island, had given him for assisting in his suicide. No gun was used; instead, Mr. Minor said, he held a knife against the steering wheel while Mr. Locker, 52, thrust his chest into the blade.

As absurd as Mr. Minor’s story may have sounded a year and a half ago, it will hardly be dismissed as frivolous when his trial begins next week.

Months after Mr. Minor’s arrest in July 2009, prosecutors conceded there was evidence that Mr. Locker, who was married with three children, might indeed have been trying to end his own life.