In my opinion ( and allowing for the video clip posted below) the solution has been right in front of the American eyes for ages, i.e. ENACT and ENFORCE STRICT Gun Control and Gun Laws.
Yes, the criminal elements will find a way around them as they always have done and always will do BUT is not 1 innocent death just 1 death too many?

And after millions of dollars are spent designing such a school...someone pulls the fire alarm and awaits the masses of students standing out in the open.

Wouldn't it be easier to design tiny Pope-mobiles for each student, complete with transparent, plastic, bullet proof boxes to hide inside?

Or make everything out of those plywood desks from the '50s. You know, the ones everyone hid underneath because they would shield children from a nuclear blast?

(If that's a high school, at least there will be dozens of places for many illicit activities to happen outside the prying eyes of adults. Drugs, sex, bullying, fights--all made much, much easier.)

In short, I think the new design is a parade of bad ideas...some of which will give birth to dozens of baby bad ideas...that, unfortunately, will grow up way too soon.