How do you mean?Armed guards at every school, and metal detectors.
Guns should be locked in a gun safe while unattended.
Children should be screened by a shrink every year with an interview - those kids with a serious problem may give themselves away.
Sometimes evil gets us, sometimes we get it - often we need guns to get it! The culprit is decadence - fostered by poor dumb ass parents who shouldn't procreate!
the shrinks are creating these killers ..