Rialto High School was placed on lockdown this afternoon after administrators reported a potential shooter on campus.
San Bernardino police say officers arrived before 1 p.m. after receiving calls about an active shooter situation. Sgt. Chris Gray said the school was immediately locked down while officers swept the grounds room by room.
Earlier today, Rialto High School was placed on lockdown out of an abundance of caution due to the reported threat of an active shooter. During the lockdown, students and staff remained safe at all times. San Bernardino PD confirmed there were no active shooters, no shots fired,… pic.twitter.com/PvzoNNNdZH
— Rialto Unified School District (@RialtoUSD) September 30, 2025
The lockdown was lifted at 2:45 p.m. and soon after students were allowed to reunite with their families. Gray said one person was briefly detained but later released. “From the initial investigation onsite, there was no active shooter, no gunshots, and no weapons,” he said.
Gray added the call may have been a swatting incident. K-9 units were deployed to assist in the search. Gray says the investigation is ongoing.
The Rialto Unified School District said students remained safe and that safety protocols were followed. Officials confirmed classes will resume Tuesday as scheduled.
This is a developing story.
