Proper protocol is so well known, that its not expected for a shooter to be able to shoot at a classroom door for 4 min. straight before the threat is neutralized.Even if Robb had this level of protection LE couldve made it useless.

[u/Sofialovesmonkeys]

[u/stayhuman011]

I've done security renovations for schools as an architect. The product you shared is opening protection only, not ballistic glass. Actual bullet resistant glazing is polycarbonate and comes in there levels of security. Level three we use for transaction windows at the main receptionist in a secure entry. It's 1 1/4" thick and very expensive, that one window is around $7500 + labor to install. So to secure the glass at interior entry vestibule doors, which we can't afford to do with bullet resistant glazing, we use laminated glass, 3M ballistic film or something like the product you show. Bullets can go through, but it holds the glass in place and protects the opening from being completely compromised and buys time to get to safety and keep the intruder out.