A driver who plowed into a Riverside bus stop, killing a woman and a 7-year-old girl, has pleaded guilty to involuntary manslaughter.

The Press-Enterprise reports 46-year-old Joe Williams was ordered Thursday to serve six months in custody of the Sheriff's Department, but his sentence could include a work-release program in lieu of jail time.

Williams was indicted after prosecutors told a grand jury that he had a history of blackouts seizures and should not have been driving.

Authorities say Williams, a parking enforcement agent, blacked out at a red light on Dec. 28.

When motorists behind him honked their horns, Williams accelerated, veered up onto the shoulder of the road and crashed into a bus bench.

Twenty-eight-year-old Melissa Bernal and 7-year-old Aniya Mitchell were killed.