First of all, I seriously doubt that the shooter in this case was aiming carefully. It sounds as if he was able to frighten his victims into submitting meekly (like the sheep we create in the public schools) so he could pop them at close range. Perhaps even contact range. I'll bet every shot he took at any other distance missed an intended target. However, in a target rich environment, it's certainly possible that even a miss would hit somebody else.
When I was a student at the University of Alabama in the late 1970's, a lot of us Army ROTC cadets had our CCW permits and carried on campus. Never a problem!
Gee, where in the heavily armed south in THIS day and age are you guaranteed to find thousands of unarmed sheep to slaughter? Answer: On campus.
Do you know that armed students from the University of Alabama mounted a defense of the campus against a yankee incursion during the War Between the States (aka "The Recent Unpleasantness" in Alabama)? They failed, but they fought with valor. My how times have changed.