If you left personal items at the store, @CoronaPD is securing the items are returning them to owners with proper ID. pic.twitter.com/mDBzQH9m0e — Corona Police Dept. (@CoronaPD) June 15, 2019

CORONA, Calif. (KABC) -- An off-duty Los Angeles police officer fired his gun and fatally shot a man at a Costco Wholesale store in Corona Friday night, police said Saturday.Corona police said the officer, who has not been identified, was not arrested or detained. However, authorities initially said a suspect was in custody following the incident. One person was killed and three others, including the officer, were injured in the shooting in the crowded store.Corona police said the shooting stemmed from when the off-duty police officer, who was shopping with his family, was assaulted by a man while the officer was holding his child.The attack prompted the officer to fire his weapon, hitting the man, along with the man's two family members, according to police.Police said the man accused in the attack was not known to the officer's family.The child was not hurt in the incident. Only one weapon, the off-duty officer's gun, was determined to be involved in the incident.LAPD released the following statement:Multiple witnesses said they heard gunshots around 7:45 p.m. while shopping at the store located at 480 N. McKinley Street. They said there was chaos after shots were fired. People ran to escape, but the doors were reportedly locked, which added to the panic."I heard pop, pop, pop, and then look, she almost broke her hand trying to open the emergency doors," said one witness, who added that he was right by the shooting when it occurred inside the store.Another shopper captured the mayhem that was heard in the aftermath of the shooting.Footage from AIR7 HD showed the large police presence at the warehouse store after it was evacuated. Following the law enforcement response, Corona police confirmed the shooting incident was stabilized, and there was no threat to the public.Corona police confirmed four people were found injured inside the Costco. One died from his injuries at the scene. The off-duty officer was treated at a hospital and released, while the two others are listed in critical condition.The person who was shot and killed in the deadly confrontation was later identified as 32-year-old Kenneth French from Riverside.Authorities initially thought they were dealing with an active shooter but quickly determined that was not the case.Investigators said it all began with an argument inside the business, and then moments later, witnesses heard several gunshots."There was apparently an argument inside, some type of argument that turned into a gunshot," said Jeff Edwards from Corona PD. "From my understanding, it is not domestic."The store reopened Saturday.Police said personal items were left inside the store during the panic and shoppers could retrieve those items with proper identification.An investigation is ongoing.