Police rapid response to school violence has become an important issue in the past decade. After the Columbine massacre in 1999, police around the country adopted new policies for so-called “active shooters.” Police would no longer respond to emergencies such as school shootings by surrounding a building and waiting for the SWAT team. Instead, the first four officers rush into the building and attempt to immediately end the threat. This system was used to end a 2003 school hostage standoff in Spokane, Wash. At Columbine, no officers entered the building until about 40 minutes after the first 911 call from the school. Critics have said that decision might have contributed to the death of a teacher who bled to death from gunshot wounds. Tom Corrigan, a former member of the NYPD-FBI terrorism task force, said five minutes seems like a long time when gunfire is being heard, but he added that it’s tough to second-guess officers in such a chaotic situation. 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! The five minutes police spent breaking into the building proved to be crucial. During that time, Cho picked off his victims with a hail of gunfire. He killed himself after police shot through the doors and rushed toward the carnage. State police spokeswoman Corinne Geller praised the officers’ response time, noting that had police simply rushed into the building without a plan, many likely would have died right along with the staff and students. “If you go in with your backs turned, you’re never going back,” Geller said. “There’s gotta be some sort of organization.” Some police and security experts question the five-minute delay, saying authorities should have charged straight into the melee. “You don’t have time to wait,” said Aaron Cohen, president of IMS Security of Los Angeles, who has trained SWAT teams around the country since 2003. “You don’t have time to pre-plan a response. Even if you have a few guys, you go.” BLACKSBURG, Va. – The bloodbath lasted nine minutes – enough time for Seung-Hui Cho to unleash 170 rounds from his two pistols, or about one shot every three seconds. During that time, Virginia Tech and Blacksburg police spent three minutes dashing across campus to the scene. Then they began the agonizing process of breaking into the chained-shut building, which took an additional five minutes. Once inside, as they sprinted toward the sounds of gunfire inside Norris Hall, Cho put a bullet through his head and died in a classroom alongside his victims. A timeline of the rampage emerged Wednesday as police provided new details about what they uncovered in the 10 days since Cho committed the worst mass shooting in modern U.S. history.