The police said a 55-year-old man was shot several times in the chest, chin and arm while sitting in the driver’s seat of a Dodge Ram on West 147th Street near Frederick Douglass Boulevard.

The police official, who spoke on the condition of anonymity because he was not authorized to disclose the information, identified the man as Mr. Martinez, whose exploits had been immortalized in hip-hop songs and in the 2002 film “Paid in Full.”

The police responded to the scene around 3:30 a.m. after receiving 911 calls and alerts from a system that detects gunshots. The man was transported to Harlem Hospital Center and declared dead on arrival.

He was found carrying identification bearing the name Abraham Rodriguez, according to the police.

His vehicle had temporary plates from Texas, the police said. No arrests had been made as of Sunday evening.

In a prison interview with F.E.D.S. magazine quoted in The New York Times in 1999, Mr. Martinez — who confessed to 14 murders before becoming a government witness — described shooting a boyhood friend, Richard Porter, in 1990 because he suspected him of cutting in on drug deals.

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“Paid in Full” also portrayed Mr. Porter’s life and his relationship with Mr. Martinez.

An accomplice had shot Mr. Porter twice, Mr. Martinez told the editor of the publication, which circulated among inmates. “He didn’t die, so I shot him in the head,” Mr. Martinez said.

Mr. Martinez said that he and an accomplice then dumped the body on City Island in the Bronx.

Mr. Martinez was raised in New York and came to play a prominent role in the violent turf battles over dealing cocaine and crack cocaine there starting in the 1980s.