San Mateo County Man Arrested for Alleged Possession of Illegally Modified Gun
SAN MATEO, CA — “On July 10, 2025, at 3:02 p.m., a San Mateo Police officer proactively stopped a vehicle driving in the area of southbound Highway 101 at Holly Street for multiple vehicle code violations. During the traffic stop, two adult males were detained, and the suspect, Josiah Garcia, was located as the front passenger. Probable cause was established to search the vehicle, and officers located a black Glock 22 pistol from underneath the front passenger seat. During an inspection of the firearm, officers observed the weapon to be loaded, with a round in the chamber. A modification to the firearm was also noted, commonly known as a “switch,” which converts a semi-automatic pistol into a pistol capable of fully automatic fire.
Based on the additional probable cause established in this investigation, Garcia was placed under arrest for violations of converting a firearm into a machine gun, concealing a weapon inside of a vehicle, possession of an unconventional pistol, possession of a multi-burst trigger, carrying a loaded firearm in public under specific conditions, possession of a machine gun, and possession of a concealed firearm that is loaded. Garcia was transported to the San Mateo County Jail where he was booked for his charges, without incident.
Shortly after, the pistol was range tested by a San Mateo Police Department Firearms Expert, and during a live-fire examination, the pistol fired 10 rounds in under one second.
ARRESTED
Josiah Garcia, 20 years old, Antioch resident
CHARGES:
PC 32625 (B)-Converting a Firearm into a Machine Gun, PC 25400 (A) (1)-Carry a Concealed Weapon in a Vehicle, PC 31500-Possession of an Unconventional Pistol, PC 32900-Possession of a Multi-Burst Trigger, PC 25850 (A)-Carry a Loaded Firearm in Public Under Specific Conditions, PC 32625 (A)-Possession of a Machine Gun, PC 25400 (C) (6)-Possession of a Concealed Firearm that is Loaded”
