A San Marcos Middle School student was arrested Monday after deputies found an unloaded handgun in his backpack.
The San Diego County Sheriff's Department said another student alerted school officials that the student was possibly armed.
Administrators questioned the 13-year-old student and he eventually admitted that he had a gun in his backpack, the SDSO said. Deputies searched his backpack and confirmed that he had an unloaded .22 caliber pistol.
The student was arrested and booked into Juvenile Hall.
The SDSO said it does not appear that the student made any threats to the school.