How long will it be before every step in this new vicious circle has a an industry, or a service provider, ready to start providing political support for continuing doing things this new money making way.
Arm the teachers. Train the teachers. Build new bunker, fortified, schools, with guard towers, and pill boxes, etc. Whole new kinds of school based surveillance systems, and of course a whole host of new monitoring, and predictive software to catch troublemakers before they even think of doing something bad. Then, certainly, there will have to be a new line of body armor clothing for the fashionable student, as well as the "in" teacher. You are limited here only by your imagination.
This, of course, as opposed to actually trying to find out why individuals are going off on such rage binges in the first place. So that, just perhaps, you might find out that a serious deficiency in the way we socialize individuals these days is at play here. That there might also be a very serious problem with the fundamental aspects of what now passes for socialization; because the process itself has been so corrupted by a now inhuman need to keep making ever more amounts of money. So much so, in fact, that we have lost sight completely of what trying to mature as human beings is supposed to be all about.
Just more to think about as you contemplate what reality ought to be about, and not simply what makes it more conducive to cash flow, and ego aggrandizement.