The officers ran back to their car and called for backup as the man allegedly opened fire. Officers reported seeing a handgun, a shotgun and a rifle, and that the shooter fired at least two of the weapons. The shootout -- which according to CHP involved 10 police officers and lasted about eight minutes -- left the suspect, who was wearing body armor, seriously wounded. He was taken to the hospital and is listed in stable condition.
Two officers were hurt by broken glass, but none were shot.
"There is no doubt in our mind, given the body armor and the extensive amount of ammunition he had, that he was on his way to do a very serious crime against either someone or a group of people," CHP Sgt. Trent Cross said.
Officers discovered a binder labeled "California" in the truck. It has so far been described only as a "list."
When local reporters called the truck's registrant, Janice Williams, she realized her truck, and her guns, were gone.
Williams told the San Francisco Chronicle that Byron, her 45-year-old son, was upset by "the way Congress was railroading through all these left-wing agenda items."
"He hasn't been able to get a job because he's an ex-felon and nobody will hire him," she said, adding that he was angry about his unemployment and about "what's happening to our country."
"I have no doubt it is him," Williams said. "He's been upset with the direction the country is going. ... He feels the people of this country are being raped by our government and politicians."
Janice Williams said she kept the guns, which were locked in safe, because "eventually, I think we're going to be caught up in a revolution." She also told the Chronicle that she had warned Byron that "he didn't have to be on the front lines."
She told California Beat that "he had a lot of angst with the politicians, both those running California and those running the country."
She said he has two prior felony convictions, one for a bank robbery two years ago. California has a three-strike law, meaning someone convicted of a third felony could get up to a life sentence.
One news station reports that Byron Williams has a long arrest record, including assault, property destruction, a DUI, hit and run and theft.
Another news story says Williams was arrested for a bank robbery in 2002. According to a Modesto Bee story from that time, one Byron Christopher Williams tried to rob a bank in Chowchilla wearing a blond wig, only to be laughed out of the branch by customers. He then allegedly robbed another bank and led police on a 100-mile-an-hour, hour long chase.
You can hear shots being fired in this video, posted by YouTube user mannyblack:
Spokesman for the CHP, the Oakland Police and the FBI did not return calls for comment.
Late update: A spokeswoman for Highland Hospital, where Williams is being treated, said his condition has been upgraded to "fair."