Karl Pierson, the 18-year-old student who shot a classmate this month at Arapahoe High School in Centennial, Colo., entered the school through a door that was supposed to have been locked, Arapahoe County Sheriff Grayson Robinson said Monday.
Robinson said the door through which Pierson entered the school was not secured as it should have been. It was an exterior door that had been propped open. Robinson also said a locked door likely would not have deterred Pierson. Robinson said the investigation has shown that the entire time of the incident was less than one minute and 20 seconds. He praised those in the school who responded quickly to the attack by Pierson that killed student Claire Davis. The gunman fired three rounds in the hallway, two in the library area, and a sixth to kill himself."
As schools around the country spent millions of dollars to enhance security following the Sandy Hook shootings last year, school safety experts said training staff and students to properly close doors and follow protocols is a more effective safety measure than any bullet-proof white board or fancy alarm system ever will be.
Pierson also had the numbers of several classrooms written on his arm along with a Latin phrase that translates, “The die has been cast.” The gunman went bowling the morning of the shooting, Robinson said.
A version of this news article first appeared in the Rules for Engagement blog.