These are the words of someone desperately trying to make sense of the events he suffered. I'd suspect they are a reflection of what a grief counselor told him..."he wanted to take away your feeling of safety...don't let him do that...you can beat him by...""The NRA claims that mass shooters love gun-free zones. Mass shooters do not target gun-free zones because they lack guns. They target gun-free zones because such places are considered sanctuaries. The shooter at my alma mater wanted to take away our feeling of safety in classrooms."
Interesting that he has taken this path since he apparently is a martial artist ("Two of my martial arts students died in the Virginia Tech shooting; neither had a chance even to stand up..."). Extending his argument to self defense in general, it makes the practice of any martial art useless unless it's only done for exercise. I wonder if that has occurred to him.