I went to High School. Liked it so much I stayed an extra year! Later in life I worked in High Schools during troubled times. Still later, we used closed down schools in law enforcement training, entering, clearing and searching of buildings and all that. And the High School I attended had metal detectors all the way back in the mid seventies. One thing I know for sure - there ain't nobody, and I mean NOBODY, who knows more about physically getting in and out of their own high school, especially the sneaking back in without getting caught than High School boys. If you want to make High Schools more secure against intruders - involve the kids who go to those high schools. Not the Dean's List kids, but the....you know the ones. And involve them at the end of their senior year, when they won't mind sharing all their secrets, it's down time anyway. Nobody knows more about high school buildings than the teenage boys who go there.