Hugh Pickens DOT Com writes: Ray Sanchez reports at CNN that the handling of Friday's shooting at Arapahoe High School, just 10 miles from the scene of the 1999 Columbine High School shooting, drew important lessons from the earlier bloodshed. At Arapahoe High School, where senior Claire Davis, 17, was critically injured before the shooter turned the gun on himself, law enforcement officers responded within minutes and immediately entered the school to confront the gunman rather than surrounding the building. As the sound of shots reverberated through the corridors, teachers immediately followed procedures put in place after Columbine, locking the doors and moving students to the rear of classrooms. "That's straight out of Columbine," says Kenneth Trump, president of National School Safety and Security Services. "The goal is to proceed and neutralize the shooter. Columbine really revolutionized the way law enforcement responds to active shooters." Arapahoe County Sheriff Grayson Robinson credits the quick police response time for the fact that student Karl Pierson, the gunman, stopped firing on others and turned his weapon on himself less than 1 minute, 20 seconds after entering the school. Authorities knew from research and contact with forensic psychologists that school shooters typically continue firing until confronted by law enforcement. "It's very unfortunate that we have to say that there's a textbook response on the way to respond to these," says Trump, "because that textbook was written based on all of the incidents that we've had and the lessons learned (PDF)."