Prolific verbiage justifying the trivially defeated does not improve the fact it is trivially defeated.
Mass murderers are best deterred, by far, by voluntarily armed citizens. What you insist on would take great effort and cost, and is easily defeated despite your extraordinary measures.
What I suggest has already saved a couple dozen lives since the Newtown massacre, at no public effort nor cost.
Prove it, and in a public school setting.