Arlington County police say a man walked into George Mason University classroom and pepper sprayed a professor.
    
The man walked into a class on the school's Arlington campus on Wednesday afternoon, jumped on a desk and announced a citizen's arrest. That's when police say the man pepper-sprayed the professor in the face. The man chased the professor into the hall, but an off-duty officer in the class caught him and held him until police arrived.
    
Officials say medics treated 12 to 15 people, including the professor, for breathing issues.
    
The school says the professor was not seriously hurt. Students were sent home for the day
    
Police say the man's name won't be released until he is officially charged. The university says he is not a student at the school.