San Mateo Police said two 15-year-olds were detained after Waymo alerted authorities that the teens were drinking and shooting projectiles from inside a driverless vehicle while being transported around San Mateo. Police said the company contacted them and that officers stopped the vehicle so they could remove both occupants safely.

In a statement, police reported that once the teens were taken out of the car, investigators determined they had been shooting Orbeez (gel water beads) from the vehicle as they drank. Police also said they considered the situation dangerous despite the use of toy-like equipment, emphasizing that items such as toy guns, water guns, and BB-style devices can still cause harm, fear, or disruption—especially when fired from a moving vehicle.

Police said the incident prompted what they described as a high-risk response, and that the case remained under review as prosecutors assessed whether charges—including those related to underage drinking—would be filed.