"Never trust an Automatic pistol or a D.A's deal"

Quoth J. Dillinger. Seems the Parkland shooter should have studied more history or something. He came to the school, not with an AR and some large capacity magazines, but with 15 10-rounders. Part way along it seems one of them jammed so he dropped the rifle and joined the rest of the students exiting the building.

So far:
Armed guard in school                                         Check
Armed cops outside of school                               Check
Background check for rifle                                    Check
10 round mags only                                                Check
Shooter banned from entering school                     Check

Blame being placed squarely on non-participants   Check