I took 9 courses in CJ while at Keene State, all with the same professor. She was a fantastic woman (likely still is), an ex-corrections officer with a highly pragmatic view on public violence.
All of her classes were trained in what she called Location Defense. Specifically, how to defend yourself when the *place* you are at is under attack. We ran drills on how to deal with a shooter, and how to take an active role. She had a colleague in body armor come in, and we learned to slam the door on the gun and then body tackle him with many people. I remember feeling pumped and alive and able-bodied, like I was trained to protect "my people." She told us that when there's a shooter, if you accept being shot, you have the power because all the power is in his gun.
It reminded me of being nine, and my grandfather teaching me how to deal with being shot. Not how to avoid being shot or how to run away from a shooter, but how to take on a shooter when you have no gun. To slap the gun down and out, because you can control where it hits if you do. I remember a scared fascination as he explained that you can survive some gunshot wounds depending on where they hit you. Before that, I think I believed that guns just killed you. I think I believed that there was a loud noise and someone just exploded in red.
I am horrified to think what they might've believed before today, and I hope that the survivors get all the help they need.