A former Los Angeles police officer, already serving a 14-year sentence on a bank robbery charge, is reportedly under investigation in connection with the shooting death of rapper Notorious B.I.G., whose real name was Christopher Wallace. No arrests have been made in connection with the rapper's slaying, which occurred in March 1997 outside the Petersen Automotive Museum in Los Angeles.

The Los Angeles Times, citing unnamed police sources and confidential documents, reports that LAPD detectives are investigating whether the murder was arranged by former officer David A. Mack and carried out by one of his friends. Detectives are also determining if Mack conspired with Death Row Records founder Marion ''Suge'' Knight to kill Notorious B.I.G. Knight is serving a nine-year prison sentence in connection with an unrelated assault.

Mack's attorney told the Times that the theory was ''ridiculous,'' and Knight's attorney told the paper that Knight doesn't know Mack. According to the Times, however, Mack and Knight grew up in the same neighborhood near Los Angeles, and police associate both with the same street gang.

The suspected triggerman is reportedly Amir Muhammad, a college classmate of Mack at the University of Oregon. Muhammad was known as Harry Billups when he was in college, and police reportedly haven't known his whereabouts since he visited Mack in prison in late 1997.

Police reportedly still haven't ruled out as possible motives either a feud between West Coast and East Coast rappers or a gang-related dispute. The murder of Notorious B.I.G., a top rapper for New York-based Bad Boy Entertainment, was widely speculated to be retaliation for the shooting death of Tupac Shakur, who recorded for L.A.'s Death Row label.

A new posthumous Notorious B.I.G. album titled ''Born Again'' was released this week. The album features previously unreleased tracks, including the demo tape that got the rapper signed to Bad Boy.