All this.
I already mentioned how it would take me MAYBE 5 minutes to enter my kid's school by just waiting for someone to walk in or walk out and "bum a ride" while the door is open. Sure, if I were to do it in my current capacity, I might get stopped at the office and ask who I am, etc. If I'm there to inflict harm, that's irrelevant at that point. Short of an armed guard and a metal detector at the entrance screening every person coming in, this is the equivalent of closing a screen door to keep rain out.
I'm not saying not to do it. Have at it. But, that, along with windows, other ways to "enter", and usual familiarity with a school by these shooters and this should be #100 on a list of things to do to address what's going on. Numbers 1-90 are "limit guns" in some form.
20 pages in and this is still being argued as a viable solution?
Other countries probably don't even lock their schools and yet that isn't resulting in shooting rampages. We are the only one with this problem to this magnitude. And the one thing that sticks out isn't the amount of locked doors or mental health or video games. It's the number of guns available to people that live here. Until we address that, none of the rest of it will make any significant dent. Enough is enough. As stated earlier, Sandy Hook was 10 years ago and all we've effectively done is train our kids how to hide and smear blood on themselves to try and stay alive. Even calling the police doesn't seem to work.
####.