Sheriff's Deputy Rich Pena says Alton McDonald, 37, was pumping gas Wednesday afternoon at a service station near his home when a pickup truck pulled up and one or more people got out and opened fire.
McDonald was struck several times in the chest and died a short time later at St. Francis Medical Center in Lynwood.
So far, nothing has been said about a motive for the killing.
In 1996, McDonald was with Death Row co-founder Marion "Suge" Knight and rapper Tupac Shakur when the musician was shot to death in Las Vegas, according to court records cited by the Los Angeles Times.
Shortly before that murder, the three reportedly had been involved in a brawl, which was captured on hotel surveillance cameras. Knight was jailed as a result of the fight after a judge determined he violated his parole on a previous assault conviction.
On Wednesday, Knight went to the hospital to visit McDonald and later paid his respects to McDonald's family, who live in Compton.