I don't see stricter gun control and better school security as mutually exclusive. It is not one or the other. At least not to me. We can do both.
Of course, we just saw what happened in Parkland. The one armed guy, who was assigned to the school, to protect the kids, hid outside instead of going in to confront Cruz. Why do you think that happened? I can't read minds, but one possibility is that he knows the sound of an AR-15, and was thinking, "I'm not going to take on one (or more) shooters who have assault weapons when I only have this handgun to fight with."
So, what is the solution to that issue? Arm the guards with AR-15's so that they think they are in for a fair fight? Why not make AR-15s more difficult to acquire, so that an armed officer is more likely to be able to make a difference.?
We can still add waiting periods, better background checks, limited number of entrances to a campus, metal detectors, armed guards at the entrance, etc. There are all kinds of ways to reduce the odds of this happening again.
So you admit you don't know what was going on but then suppose the inner turmoil then solve fake problem? Come on...
Just as easy is to not hire pvssies to guard kids. Or arm him better. problem solved.