LOS ANGELES — Police body camera video released Monday shows an officer opening fire on an assault suspect in a shooting that killed a teenager who was in a nearby store dressing room two days before Christmas.

Authorities said a 14-year-old girl, later identified as Valentina Orellana-Peralta, was killed, probably by police gunfire, as she was in a dressing room behind the intended target Thursday morning in a Burlington store in North Hollywood. An unmarked wall separated her from the man who was believed to have assaulted a woman with a bicycle lock before police fired at him.

Edited body camera and security video released by the Los Angeles Police Department on Monday shows a group of officers, one with a rifle, moving toward where the suspect was believed to be, on the second floor of the store.

“She’s bleeding, she’s bleeding,” one of the officers says as the group approaches an aisle. A woman is on the floor nearer to them; the suspect is at the far end.

The officer with the rifle opens fire over the victim as the suspect appears to move away.

The suspect was also killed.

“We at the LAPD would like to express our most heartfelt condolences and profound regret for this innocent victim,” the police department said in the video. “There are no words to describe the depth of the sorrow we feel for this tragic outcome.”

The violence started with the suspect entering the store with a bike and a lock and attacking customers, according to video and its police narration. At one point he took a woman’s bag, the police department said in its description.

At the same time, dispatchers were receiving differing reports about what was happening at the store, including an assault with a deadly weapon and, in the police department’s words in the video, “a possible shooting in progress.”

It wasn’t clear whether the girl was trying on clothing or hiding from the violence outside.

The Los Angeles Times reported that a dress was found in the room where her body was found.

Civil rights lawyer Benjamin Crump said he and co-counsel Rahul Ravipudi have been retained by the girl’s family.

In a statement, Crump said the girl was trying on clothes when she was killed. He said he and Ravipudi would hold a news conference Tuesday.

Police Chief Michel R. Moore said in a statement: “This chaotic incident resulting in the death of an innocent child is tragic and devastating for everyone involved. I am profoundly sorry for the loss of this young girl’s life and I know there are no words that can relieve the unimaginable pain for the family. My commitment is to conduct a thorough, complete and transparent investigation into the circumstances that led up to this tragedy and provide the family and public with as much information as possible.”

The shooting is the subject of investigations by the police department, the district attorney and the state attorney general.

Hayley Walker contributed.