Some notes on the Arapahoe High School Shooting

The shooter was "very proud of being a socialist."

Attacker planned on killing multiple people and had many different types of weapons.  From Fox News:

The 18-year-old gunman who opened fire inside a Colorado high school Friday, injuring a fellow student and then fatally shooting himself, had entered the building with a shotgun, a machete and three incendiary devices in his backpack, and planned to hurt multiple people, authorities said Saturday. 

Arapahoe County Sheriff Grayson Robinson said Karl Pierson likely was motived by retaliation against a faculty member -- probably a librarian at the school -- when he opened fire Friday at Arapahoe High School. Robinson said it appears the librarian was the initial target but that Pierson planned to hurt multiple people. 

Robinson said at a news conference that the teen bought the pump-action shotgun legally Dec. 6 at a local store. . . .

As often happens in these attacks, when someone confronts the attacker they simply give up.  From NBC News:

The 18-year-old Colorado man who shot a fellow student before killing himself Friday intended to shoot numerous people, but his rampage was interrupted by a school resource officer who responded to the shooting, officials said Saturday. . . . 

Confronted by the officer, the teen committed suicide less than a minute and a half after he entered the building, armed with a shotgun and multiple rounds of ammunition that he purchased legally, the sheriff said. . . .

More details from CNN: 

The rampage might have resulted in many more casualties had it not been for the quick response of a deputy sheriff who was working as a school resource officer at the school, Robinson said. 

Once he learned of the threat, he ran — accompanied by an unarmed school security officer and two administrators — from the cafeteria to the library, Robinson said. “It’s a fairly long hallway, but the deputy sheriff got there very quickly.” 

The deputy was yelling for people to get down and identified himself as a county deputy sheriff, Robinson said. “We know for a fact that the shooter knew that the deputy was in the immediate area and, while the deputy was containing the shooter, the shooter took his own life.” . . . 

They were just very lucky that there was an armed deputy sheriff available.