Just the Facts, Ma'am

On the surface, the notion that arming teachers is a viable solution to the complex issue of school shootings is absurd.  It's ridiculous for so many reasons, not the least of which is the destruction of the learning environment that would surely be a consequence.  Oh, I know that an active shooter roaming the hallways is a greater disturbance to the learning environment, but what I'm suggesting is that any proliferation of firearms in or near a classroom diminishes the idea that this is a place of learning and that inside the walls of a classroom resides a learning community.
I get that one well-trained person might make a difference during an active shooter incident but to add the idea of arming teachers onto the job description of an already overstressed profession is both repugnant and ludicrous.

I say this because of the reality of a teacher's day.  Unless they walk around their rooms with holsters or have a rifle rack behind the desk, the chances of a teacher making any kind of a difference should an emergency arise is nil.  Real classrooms are crowded and cluttered. They look like 32 people wor there. Closet space is limited, if not scarce. Besides, what makes anyone think that teachers could easily fire a gun at another human being? We are abler and interested in helping someone in distress without adding another violent solution to the mix.  Some could, to be sure, but the vast majority are there to help, not corral psychotic misfits with automatic weapons.
Being a teacher and a police officer have a few things in common, but far more differences exist.
When I see cops frustrated by the fact that some people they stop don't seem to respect them or obey their commands, I think a teacher would probably be better suited to deal with the next few minutes of the encounter.  Teachers, more often, try to see and deal with the whole person.  I know there are cops that do that too, but, sadly, they don't often make the headlines and, unfortunately, they are in the minority.  Both occupations get worn down by the number of needs they must respond to and by those who are vulnerable to a surplus of everyday expectations and demands.
As the 20th century model of public education continues to change and adapt to the new realities that technology has wrought, my advice would be to put more emphasis on mental health both in courses and in support systems available.  Until we do, we'll be a culture where it remains far easier to ban a book than an assault rifle