The gunman who killed a shopper and critically injured his parents Friday inside a busy Southern California Costco was an off-duty Los Angeles police officer who is now under investigation.

Authorities did not initially identify the shooter as an LAPD officer after witnesses said he fired as many as eight rounds during an argument in the store in Corona. The shots triggered a panicked stampede of fleeing shoppers. None of the gunman’s victims was armed.

The officer, whose name has not been released, said he shot 32-year-old Kenneth French when French attacked him. A cousin described French as a “gentle giant” who was mentally disabled.

Corona police said in a statement Saturday that “without provocation, a male unknown to the officer’s family assaulted the officer while the officer was holding his young child. This attack resulted in the officer firing his weapon, striking the male and two of the male’s relatives.” The statement asked for any witnesses to come forward.

Some witnesses the night of the shooting told TV reporters that a woman, not a man, was holding a child in her arms during a loud “argument.”

Cell phone video from inside the Corona Costco captures the chaos and screaming. The customer who shot this video was picking up steaks for Father’s Day dinner when she heard 7-8 gunshots. @CoronaPD confirm 1 man dead, 3 injured incl the suspected shooter. Unk motive @NBCLA pic.twitter.com/ZiOdE7mC3A — Hetty Chang (@HettyNBCLA) June 15, 2019

Corona and Riverside County authorities are continuing to investigate the shooting. The LAPD has also launched an internal investigation, PBS reported. The LAPD told a KTLA-TV reporter that the officer involved in the shooting has been “assigned to his home.” The Los Angeles police commissioner told the local CBS affiliate that an independent inspector general would examine the case.

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French lived at home with his parents in Riverside and had the mental capacity of a teenager, Rick Shureih, French’s cousin, told the Los Angeles Times.

“He’s never been violent in the past,” Shureih added. “He’s always been very cooperative and kept to himself.” He described French’s parents, Russell and Paola French — who were still in critical condition Monday — as the “sweetest people in the world.”

The off-duty officer insisted on being taken to the hospital the night of the shooting, but it wasn’t clear that he was injured, a police spokesman told reporters after the confrontation. The officer’s child was uninjured.

On Monday, Shureih posted on his Facebook page: “City of Corona Police Department, my family has faith that you will do the right thing and arrest the gunman! Our family has witness accounts that do not match up to the original story. We are a pro police family. I have many friends in Law Enforcement. We need justice to prevail!”

On Monday, three other people were shot in the parking lot of another Costco store in Chula Vista, California. The shooter opened fire on his former girlfriend and her new boyfriend, who had been shopping there, police said. The gunman then turned the gun on himself and was declared dead at a local hospital. His victims were being treated for multiple gunshot wounds.

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Update to the Costco shooting in Chula Vista @fox5sandiego pic.twitter.com/besJmFKZYQ — Andrew Nomura (@NomuraReports) June 17, 2019

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