Inside look at how police train to protect Columbine schools

The Denver-area manhunt for a teenager said to be “infatuated” with the Columbine High School massacre revived fears of a new attack on the school. In the nearly 20 years since 12 students and a teacher were killed at Columbine, 122 people have died in mass school shootings across the country. Barry Petersen got rare access to security preparations designed to prevent another shooting at Columbine.

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