A man whose truck was being impounded suddenly grabbed a rifle and opened fire, killing a California Highway Patrol officer and wounding two others before he was killed, authorities said.

Other drivers ran for cover and two people were slightly injured as dozens of bullets flew shortly after 5:30 p.m. Monday just off a freeway in Riverside, east of Los Angeles.

“We don’t know his motive for this crime,” Riverside Police Chief Sergio Diaz said. Investigators were still gathering evidence at the scene Tuesday morning.

KABC-TV reported that a man identified the shooter as his son, Aaron Luther, 49, of neighboring Beaumont.

A CHP officer was doing paperwork to impound the pickup truck when the man reached in, grabbed a rifle and fatally wounded the officer, authorities said.

The officer was identified as Andrew Moye, Jr.

“I am devastated by the tragedy that unfolded earlier in Riverside. Tonight, I mourn the loss of one of our own,” CHP Commissioner Warren Stanley said in a tweet.

Family members said Moye was 33 and had been with the CHP for about four years.

“He was so kind,” his stepmother, Debbie Howard, told KTVU-TV. “You’re not going to hear one bad word about him. He loved this job.”

Two other CHP officers were wounded, one critically, as officers from several agencies fought the man.

“It was a long and horrific gun battle,” the chief said.

Dennis Luther of Riverside said he watched the shootout on television.

“It’s hard. I love him. And I’m sorry for the policeman,” he told KABC-TV. “I’m devastated. I just can’t believe it.”

Luther said his son served prison time for attempted murder but was released more than a decade ago. He says he doesn’t know what his son was doing with a gun as a felon, which is illegal.

After his truck was impounded, Aaron Luther called his wife to pick him up, his father said.

When she arrived, the tow truck was there.

“She said she heard ‘pop, pop, pop’ … gunfire, and then a bullet went through the windshield of her car,” Luther said of his son’s wife.

The father said his son recently seemed depressed, was having knee pain and marital problems but was devoted to his two children and a stepchild.

“He lived for his kids. That’s what motivated him,” Luther said. “So I don’t know what overcame him. I mean, I wish I did know.”

Two people received superficial injuries and “they’re going to be OK.” Parker said.

Jennifer Moctezuma, 31, of Moreno Valley told the Los Angeles Times that she was driving home with her 6-year-old twins when a bullet flew through her front windshield.

Charles Childress, 56, a retired Marine from Moreno Valley, was in the car behind her.

He led the family as they crawled to the bottom of a bridge to hide and none were harmed, the Times reported.

“He’s my hero,” Moctezuma said.

Authorities did not immediately say what prompted the officer to stop and impound the truck. Investigators didn’t immediately know where the gunman came from or where he was headed, Diaz said.

Gov. Gavin Newsom ordered flags at half-staff Tuesday in the state Capitol.

“Our hearts ache over the tragic loss,” Newsom said on Twitter.

After the shooting, dozens of law enforcement officers gathered outside of the hospital in nearby Moreno Valley. Snipers were posted on the roof as a precaution.

Dozens lined up and saluted as the officer’s flag-draped body was removed from the hospital and placed in a hearse. Motorcycle officers then led a procession as the hearse was driven to the county coroner’s office.

(AP)