Castro Middle School is located in a building across the street from the main Belmont High School campus.
Los Angeles police said Thursday night they believed the violent incident at Salvador Castro Middle school was accidental. The suspect, he added, "didn't mean to shoot" another 15-year-old girl in the wrist.
"They thought it was a toy gun, but then it shot", he told KACB.
Three others - a 30-year-old female staff member at the school and two other students, an 11-year-old boy and a 12-year-old girl - suffered superficial face and head injuries, police said.
The boy was initially listed in critical condition but doctors said that the bullet didn't hit anything vital or cause any life-threatening injury.
Police lead a 12-year-old suspect away from Sal Castro Middle school following a shooting on February 1, 2018.
Steven Zipperman, chief of the Los Angeles School Police department, called the incident "very traumatic" for the kids in the classroom.More news: Kenyan government accused of media crackdown in wake of opposition mock inauguration
"We would love to be able to talk to her more fully in an interview and just get to the intent and motive", Arcos said.
The shooting was reported to authorities around 8:55 a.m. Thursday.
Police are still trying to determine how the girl obtained the weapon. He said investigators would present their case Friday to the district attorney's office for filing consideration. A lot of anxious parents and relatives were waiting outside the campus.
"She said, 'If I give you the gun will you hide it for me?'" he said.
'Our children now see more shootings and deaths than we ever did in my lifetime, ' USC Medical Hospital assistant director Inez Beckon-English said. Westlake, a mostly Hispanic area, is home to more than 20 schools.
However, an audit last April of 20 schools found that some schools failed to do the searches daily and that a quarter of them didn't have the right metal-detecting wands.
At an informal presentation in January of good-attendance certificates, Principal Erick Mitchell said his campus was becoming a destination for families who wanted a smaller school setting.