A 14-year-old girl killed by Los Angeles police when they opened fire on a suspect who was allegedly assaulting someone in a North Hollywood clothing store on Thursday has been identified as Valentina Orellana-Peralta, according to the Los Angeles County coroner’s office.Orellana-Peralta was in a changing room with her mother when an officer fired a round through a wall near the assault suspect, striking her and killing her at the scene, according to preliminary information from police.The teenager was at the Burlington store trying on dresses for a quinceañera, a Los Angeles Police Department source confirmed to The Times.The assault suspect, who has not been identified, was also shot and killed by police, the department said. A woman who was injured by the suspect was transported to a local hospital, police said.LAPD Chief Michel Moore called the girl’s death “absolutely heartbreaking,” and promised a thorough investigation, as did William Briggs, president of the Los Angeles Police Commission. California Atty. Gen. Rob Bonta said the state Department of Justice would also investigate the shooting under rules set by a law that took effect July 1.Officers responded to a call about an assault with a deadly weapon at the store in the 12100 block of Victory Boulevard about 11:45 a.m. Thursday and shot the suspect a short distance from a woman “suffering from various injuries and bleeding,” police said. The unidentified woman was later taken to the hospital for treatment of her injuries, police said. Her condition was not immediately known.During a search of the premises for additional suspects or victims, an officer found the slain girl, LAPD officials said.“One of the officer’s rounds penetrated a wall that was behind the suspect, beyond that wall was a dressing room,” according to a tweet from the LAPD’s media relations office. “Officers searched the dressing room and found a 14 year old female victim who was struck by gunfire.”A heavy metal cable lock — no gun — was recovered from near the suspect, police said.Moore promised to release body-camera and surveillance video from the incident by Monday.This story will be updated.