Formerly a Protagonist (i.e. a good guy), the excessive stress of being surrounded by insufferable assholes turned our friend here into the menacing school shooter. Armed with a powerful rifle, he turns up at 60 to 90 seconds or so into the proceedings to clear the basement himself.
Note: in one player games the School Shooter appears slightly later in every basement to give you more time to clear each area.
A proud member of the Trenchcoat Mafia, the school shooter enjoys the complete masterworks of KMFDM, zippo lighters, and freedom of speech.The school shooter regenerates indefinitely so you shouldn't engage him. If he shows up, just clear the remaining enemies ASAP and hope for the best. He is known to destroy any obstacles between him and you with his mighty rifle, so you can't hide from him for long periods of time.