LOS ANGELES -- Four law officers were shot and wounded, three of them critically, during a 13-hour outbreak of violence in Southern California that left police stunned yesterday.

Highway Patrol motorcycle officer Gary Baker was gunned down by a man during a routine traffic stop at about 8:30 a.m. in Los Angeles, California Highway Patrol Chief Ed Gomez said. Baker was hospitalized in grave condition, officials said.

At 7 p.m. Friday two Los Angeles County sheriff's deputies and a teen-age boy were wounded in a gunfight during a narcotics raid at a South Los Angeles home.

Deputy Jack Miller, 33, shot in the head, was listed in critical condition following surgery. Deputy John Dickenson, 29, was in fair condition with a gunshot wound to the left arm.

Investigators also found a man shot to death inside the home following the shootout and were attempting to determine whether he was a victim of the gun battle or had been killed earlier, Deputy Hal Grant said.

Around midnight in San Diego, police officer Jerry Hartless, 26, was critically wounded when one of five suspects he and his partner were chasing turned and shot him in the head, Lt. James Caster said.