Lots of wisdom in that article. Many of us are always preaching "when shtf your threat isn't going to be standing there waiting for you to shoot", yet in many of these school shootings, many of the victims are in fact standing, crouching, laying, etc, trying to hide in place. Your average shit bag, cluster B individual, likely practices shooting at static targets, if they practice at all.

Disclaimer: this is just my opinion, no sources or facts involved.