"Shooter detection system" in school costs $20-100k

Apparently we need computers to tell us if there is a school shooting in progress. Though the education seems to be more widespread it produces a terrible product as noted in my last post, they will chalk up tens of thousands to install these systems in classrooms. I can imagine all the false-alarms these things can generate from slamming a door, knocking over a desk, dropping a book or whatever. They will be the school shooting version of anti-theft alarms on vehicles perhaps? Then everyone in the school will be alerted when to stop class to pull out the bulletproof blankets and get behind the bulletproof whiteboards.