The NY Post reports that investigators are focusing on money as the probable motive behind Jam Master Jay's murder:

COPS want to question an acquaintance of slain disc jockey Jam Master Jay because they think he may have been the lookout for the hit man who executed the pioneer rap star in his Queens recording studio, The Post has learned.

The man they're seeking is an ex-con and convicted drug dealer from Queens who fled the city just days after the rap legend - whose real name is Jason Mizell - was executed, sources said.

Investigators believe Mizell was killed over money, perhaps as much as $10,000 that someone felt the Run-DMC star owed him.

Sources say the ex-con, whose name is being withheld, rarely visited Mizell's recording studio at 90-10 Merrick Boulevard, but was spotted there by witnesses just hours before the Oct. 30 shooting.

Police think he may have stood vigil outside the studio to tip off the hit man that Mizell had arrived and was inside.

....Detectives are also pursuing other avenues in their far-flung investigation into Mizell's business dealings for a possible motive. At the time of his death, Mizell owed several hundred-thousand dollars in taxes to the government.