Atascadero High School was briefly placed on lockdown and shelter in place as police pursued a suspect with a gun, the city confirmed to The Tribune.
The suspect brandished a gun during a suspected fight around 3:20 p.m., initial scanner traffic said.
The suspect is wearing a black shirt, black pants and carrying a black backpack with shark teeth attached to it.
The suspect is still at large at this time, but has headed away from the high school.
The lockdown and shelter in place were both lifted around 3:40 p.m.