Sounds like the NRA had it right.
Check it out:
As they investigate the latest school shooting in the United States – Friday at Arapahoe High School in Centennial, Colo. – one thing is clear to law enforcement officials there: The presence of an armed deputy sheriff on regular duty at the school was the key factor in preventing more deaths and injuries.
As soon as he heard the first of five gunshots, that officer and the two school administrators he was talking to raced toward the commotion shouting their presence and ordering students and staff to follow the school’s lock-down protocol.
As a result, Arapahoe County Sheriff Grayson Robinson said at a briefing Saturday afternoon, the heavily-armed shooter realized he was about to be confronted by an armed officer, and he took his own life.