Each of these shooters lately were insane, and at least two had some Satanist leanings. I would not put it past the government at all to make these people useful (albeit insane) idiots.
I went back and looked at Wikipedia articles about the original "school shooting" in Stockton, Calif., in 1989, that prompted California to pass a broad ban on AK- and AR-type "assault rifles". Shooter Patrick Purdy was a drifter, loner, oddjobs, druggie, half-crazy .... and had peace symbols and slogans on his clothing. Yup, another one of theirs.
This is all about totalitarian ideology and State confiscation of our weapons and establishing a monopoly of force -- a tyranny. Schools, kids, and lone drifters have nothing to do with the underlying motive for gun-grabbing.