Butte High School was placed on lockdown for about an hour Monday after a student made angry comments and then left the building.
All the entrances and exits to the building were closed around 11 a.m. after the 18-year-old male left and police searched for him, said Undersheriff George Skuletich. A text message about the lockdown was sent to parents.
Police located the student outside of the school, talked with him and took him to St. James Healthcare for a mental evaluation but he was not arrested, Skuletich said.
There were no weapons involved in the incident and the lockdown was lifted around noon.