A teen boy is behind bars on suspicion of walking onto the Montgomery High School campus with a knife. Police say the boy, who is not a Montgomery student, was wearing a ski mask and entered the school twice through the staff parking lot on Monday morning. He was allegedly intoxicated and threatened a 15-year-old student who he did not know. Staff escorted him off campus after he returned less than an hour later. He was arrested at a grocery store near the school after running away from a Santa Rosa police officer. The knife has not been recovered.