The National Threat Assessment Center, a division of the US Secret Service has issued a followup report to the initial school shootings at Columbine HS. The new report emphasizes the following:
The overwhelming number of school shooters are “students, former students or students from other schools.” They are not intruders. So we have been preparing for the wrong attackers. The people who commit school violence know the schools. We have created a multi million dollar industry with secure door locks, “bullet-proof” back packs and the rest of the “harding” of schools.