Here in conservative God’s country, we have locked high school doors with sheriff’s deputy at the entrance. That is, entry and exit during class room hours is restricted. I’m not sure about what measures are taken at elementary and middle schools.
I think the policy has worked well since implemented I believe post columbine.
At least one armed intruder was taken down and arrested.
I just did some quick googling for these stats: The average high school campus built after 2002 is 125,000 sq ft in size, close to 2.5 acres. That’s the average. 70% of high school students attend a school with more than 1000 students and half of all high school kids attend a campus with more than 1500 students.
I am glad your Sheriff’s deputy stopped an intruder. But you were in high school once. There is no good or efficient way to secure a perimeter of 125,000 sq ft without making it a prison or a military camp. It is the same logic as used in the general gun control debate. They will put a fence around the campus and tell everyone they must enter via the main entrance and show ID and walk through a metal detector etc. And all the good people will follow the rules and go through the main entrance. Those who wish to flaunt the rules, including potentially some bad people, will just cut a hole in the back fence at night and smuggle in contraband, just like they did when we were kids.