San Francisco police officers pulled a high-risk stop on an autonomous vehicle in the Richmond District before dawn on September 3, and what they found inside changed a routine call into a felony weapons case: a loaded, AR-styled ghost gun, along with marijuana and mace spray, tucked with two juvenile passengers.
Officers responded to the 800 block of 40th Avenue at approximately 3:52 a.m. on September 3 after a report of two passengers riding in an autonomous vehicle with a firearm. Officers arrived, conducted a high-risk vehicle stop, and detained both passengers.
A search of the vehicle turned up the loaded assault rifle, which police describe as a ghost gun — an untraceable weapon typically assembled from unserialized parts. A search of the suspects themselves turned up suspected marijuana and mace spray, the department said. Investigators developed probable cause to arrest the male and female juveniles on charges related to illegal possession of a firearm, and both were booked into the Juvenile Justice Center. Because of their ages, SFPD said their identities will not be released.
How Robotaxi Monitoring Can Trigger a Police Response
SFPD's release does not say how officers first learned of the firearm inside the vehicle, but the case fits a pattern that has emerged elsewhere in the Bay Area as driverless fleets expand. Under Waymo's terms of service, riders must generally be at least 18 years old without an adult in most California markets, and the company relies on live interior cameras and remote monitors that can disable a trip or alert authorities, according to J&Y Law.
Just two months earlier, San Mateo police executed a similarly high-risk stop on a Waymo vehicle after remote operators watching live internal video saw two 15-year-old passengers drinking alcohol and firing a toy gun loaded with gel pellets out the windows, as reported by CBS News. Remote operators in that case disabled the vehicle and alerted local police, who detained the teenagers.
Police stops of driverless vehicles carry their own procedural wrinkle.
Ghost Guns Remain a Persistent Local Problem
The rifle recovered on 40th Avenue adds to a string of ghost gun cases involving minors across San Francisco. On March 8, 2025, officers arrested two male juveniles near the Stonestown Galleria after a foot chase turned up a ghost gun and an AR-style replica rifle, booking one suspect into the Juvenile Justice Center, per the same CBS News account. The San Francisco Standard has reported a major increase in ghost guns in the city, according to the San Francisco Standard.
The surge is not unique to San Francisco. California Department of Justice statistics published in 2024 show law enforcement recoveries of untraceable ghost guns statewide climbed from just 11 weapons in 2014 to more than 10,000 annually in both 2021 and 2022, according to the Miranda Rights Law Firm. State lawmakers responded with Assembly Bill 1621, enacted in 2022, which imposed broad restrictions on unserialized firearm precursor parts and completed ghost guns, per the Giffords Law Center.
Officials have also focused on the ghost-gun supply chain.
Juvenile Firearm Possession Carries Steep Penalties
It remains unclear what specific charges prosecutors will ultimately file against the two juveniles arrested on 40th Avenue.
The case remained active.
