An ex-con wanted for questioning in the sensational murder of rapper Jam Master Jay has been nabbed in an armed holdup on Long Island, The New York Post has learned.

Sources identified the man as Ronald "Tinard" Washington, 35, a convicted drug dealer from Hollis, Queens, who is an acquaintance of the slain rapper.

Investigators suspect he may have been the lookout for the "hit" man who pumped a bullet into the head of the pioneer rap star in his recording studio last Oct. 30.

Washington rarely visited the rapper's recording studio, but was spotted there by witnesses just hours before the killing, and vanished two days later when cops went looking to question him.

Detectives had been hunting Washington as far away as Baltimore.

On Monday, Washington and another man, Ernest William, 23, allegedly robbed a clerk at the Floral Park Motel of money and jewelry, fleeing in a 2001 Hyundai that was chased by police.

After a 20-minute chase, Washington's car slammed into another car in Bellerose, Queens, where William was grabbed at the scene, and Washington tackled after a brief chase on foot.

Washington originally gave his name as Mark White, of Hempstead, L.I., but when a fingerprint check revealed his true identity, authorities notified detectives at the 103rd Precinct in Jamaica. Those cops are probing the killing of Jay.

The rapper, whose real name was Jason Mizell, was a founding member of the seminal rap group Run-DMC.

The New York Post has reported investigators believe a simmering feud over an eight-year-old $30,000 drug rip-off in California led to the assassination.

Detectives believe the murder stems from a deal gone bad involving Jay, who had no experience in drug deals, and the prime suspect in his slaying, Curtis Scoon, who felt Mizell should repay his loses because they were ripped off by Mizell's acquaintances.

Mizell refused to pay, insisting he was also a victim, but the 6-feet-4-inch, 250 pound Scoon harbored a grudge, and in early October, Scoon allegedly made several threatening calls to Mizell.

Investigators believe Scoon plotted to hit on Mizell, hiring the killer and a lookout.

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