SAN DIEGO — A 21-year-old man was arrested Monday on suspicion of being in possession of a “ghost gun” in Otay Mesa, authorities said.

According to the San Diego County Sheriff’s Department, deputies from the East Mesa Reentry Facility and George Bailey Detention Facility were patrolling their parking lots in 400 block of Alta Road around 3 p.m.

Authorities say a car was seen entering a restricted area, prompting deputies to make a traffic stop. With consent of the vehicles occupants, deputies searched the car.

According to SDSO, a loaded 9mm “ghost gun” with no identifying serial number was located inside of a backpack on the passenger floorboard. 

During the investigation, Isaiah Cisneros admitted the “ghost gun” belonged to him, SDSO said. He was arrested and booked into the San Diego Central Jail for possession a firearm on jail grounds, possession of a concealed firearm and possession of a “ghost gun.”