L.A. School Police responded to reports of a "man with a gun" at the school. Officers were directed to the student and found the gun after searching him, according to officials.
"An unserialized 'ghost gun' was recovered from a 9th grade student's backpack after staff was tipped off by anonymous students who saw the subject with the gun," said the L.A. School Police Association in a statement posted to social media.
A ghost gun is an untraceable firearm, usually without a serial number, that can be assembled together with parts bought from the internet.
Authorities say the student was taken into custody, and the campus is safe. No one was injured in the incident.
Detectives are looking into where the student may have gotten the gun. The investigation is ongoing.
No further details were immediately known.