. >> reporter: madalena deandrea is a graduate and a former student body president of the university of colorado at boulder. her father, a.j. deandrea, is a deputy police chief of the arvada, colorado police depament and a former swat team member. he was one of the team leaders who responded to the columbine high school mass mder 20 years ago. >> we had a plan, we we prepared, it was just the wrong plan.or >> rr: in 1999, when a gunman was barricaded in a building with hostages, thenf standard lawcement protocol was to set up a perimeter around the building and call the swat team to begin negotiations, but columbine wasn diff the gunmen were only interested in killing those inside the school. >> by the time swat gets there it's way too l ie. >> reportewas, for deandrea, a personal and professional failure. >> it tookolumbine for us to change our mind, to change the way that we view t world. columbine is the watershed moment when we start to talk about acti shooters,ot just school shootings, but active ootings. >> reporter: over the past 20 years, deandrea has worked tond develop new