In some states, schools can't kick out bad students for any reason due discrimination laws. So they just shuffle the lunatic around the district. The parents are losers who use the school as daycare because they don't want to deal with the psychopath living under their roof.
It's very rare that a school shooter didn't have a long list of behavior issues and that the parents were never called to meet the principal. I just can't stand parents like that.
IF YOUR KID HAS A LONG LIST OF BEHAVIOR ISSUES AND YOU'VE BEEN CALLED TO THE COUNSELOR OFFICE SEVERAL TIMES, PULL OUT YOUR LOSER KID FROM THE SCHOOL!!!