RICHMOND -- A 25-year-old mother of four and her 24-year-old friend were slain early Monday in an ambush-style shooting in central Richmond that happened as the victims pulled up to an apartment complex gate, police said.

Rose McFadden was a passenger in Antoine Williams Jr.'s car, which arrived at the Barrett Terrace complex on Nevin Avenue at 2:40 a.m., police said. The two had spent the night out in San Francisco, investigators said.

At least one gunman approached the car on foot and opened fire. McFadden got out and tried to run, but was shot and died at the scene, police said. Williams hit the accelerator and blasted through the gate, then crashed into a concrete wall surrounding a trash bin.

He was shot in the head and body and was flown by helicopter to John Muir Medical Center in Walnut Creek, where he died just after noon.

No arrests have been made. Detective Nicole Abetkov, a police spokeswoman, said McFadden - who lived at the apartment complex with her children, who are all under 7 - and Williams did not seem to be involved in criminal activity. They may have been targeted at random in a dispute over respect and gang turf, she said.

Abetkov, though, said investigators did not yet know whether the shooting was tied to a recent upsurge of violence between factions in north and central Richmond.

The killings were the 22nd and 23rd in the city this year. There were 21 homicides in Richmond in all of 2010.

Like the police, McFadden's neighbors called her an unlikely victim. At the apartment complex's community center, where volunteers were packing lunches for needy families, 55-year-old Cheryl Tucker said McFadden was a "sweet" young mother whose death proved that "the devil is working."

"She didn't deserve that, period," Tucker said. "I don't know if they (the killer or killers) were on dope or what. But that wasn't for her - sounds like they were just sitting outside waiting to kill somebody."