A 12-year-old girl who was arrested after accidentally shooting a classmate in the head and injuring three others thought the weapon was "fake", one of her peers alleged.
Preliminary information indicated she was 12, said Los Angeles Unified School District Police chief Steve Zipperman.
Salvador Castro Middle School has a total enrollment of 428 students and 22 full-time teachers.
According to the Los Angeles Police Department, the investigation has been presented to the District Attorney's Office for consideration of possible criminal charges against the girl, who was detained immediately after the shooting at the Westlake district campus.
"Someone made a decision to bring a gun, I guess someone was accidentally playing around with it", the 12-year-old seventh-grader, whose guardian asked that he not be identified, told the Los Angeles times.
School officials say students at middle and high schools are subject to daily random searches for weapons using metal-detector wands. No motive is yet known, he said. "I need you here, I'm scared".
Three others, aged 11 to 30, suffered minor injuries, police say.
The girl, whose name has not been revealed because of her age, has been charged with negligent discharge of a firearm that left five people injured, including two students who sustained gunshot wounds.
The middle school is located in a building across the street from the main Belmont High School.
Pictured the 12 year old female shooter being escorted upon her arrest.
One parent told ABC Los Angeles station KABC-TV that the shooting took place next to her son's classroom.
"I said 'No, '" he said.
Authorities said they were trying to determine how the gun was brought on campus.
Classes continued as scheduled on Thursday, and Friday would be a normal school day, officials said.
"I just saw something pop", Lopez said. Download it today and continue to enjoy STV News wherever you are.
The register is 92 per cent Latino and most students are from low-income families.