A report of a man with a gun in a creek on Thursday prompted the brief lockdown of Woodside Elementary School, according to the San Mateo County Sheriff's Office.
The school is located at 3195 Woodside Road and the suspect was allegedly found behind it sometime before 3:30 p.m.
Deputies and detectives responded to the scene to investigate the report and scour the area. The suspect, who is believed to have a thin build and was wearing a white jump suit, was not found.
The school lockdown was lifted at 4:25 p.m., deputies said.
Additional details were not immediately available.