We really need 100k of tech to tell that someone is inside a school building shooting? Really? This is just stupid.
Also, this system was designed for use in the field and relies largely on many channels of audio from different sources to converge and tell where a shooter is at a distance. The application here is way, way more simplistic. All they need is a sensor with microphone in each large open area with a trigger to alert for it's sector alone not a massive, complicated computer driven system meant to triangulate point of origin for a bullet moving through though the air. You could build something like this easily with one raspberry pi or old sun microsystems sunspot per open area with a microphone attached to it and one central server.