hey i'm sure you all know this already, but just to reiterate:
the towns where these mass casualty "events" happen are probably covens of some sort. judging by SH, the insiders probably co-exist with normies to add realism to what is essentially an inbred hive. these kids may in fact be a literal all-star team of assassins-in-training. they have probably been MK'd from birth (or before) as sex kittens, etc.. with SH, there is a connection to a local "school of rock", which IMO suggests that they are also being trained to assume roles in (pop) music. think of it as programming the most valuable asset possible, one which can provide a revenue stream in several ways. they get lent out to play roles with other "families", so it's tough to know who is even related to who (aside from, "all of them to all of them" ;)
if you go back and examine other high-profile cases, it becomes clear that there are similar towns/hives across the country. lord knows what they have been training for.
WHY was it ever allowed to go this far?