Police found the bodies in the driveway of a home about 1:45 a.m., but had little information several hours later about possible suspects or what prompted the shooting, said Lt. Larry Nigel.
Authorities did not immediately know the names or ages of the victims, but suspected the men might be related. The fifth victim was hospitalized in stable condition and the prognosis was good, Nigel said.
Investigators remained on the scene midday interviewing witnesses. It was too early to say whether the shooting was gang-related, Nigel said, but one officer said it was possible gangs were involved given the location. The residence sits about 150 feet from a business district near the once-popular Route 66.
''That's one of our local longtime street gang areas,'' said watch Cmdr. Richard Taack.