could happen anywhere.
The tragedy isn't as unlikely as you might think, as any city council reporter could tell you.
In my younger reporting days, I'd seen more than a few city council gadflies who seemed around the bend. They'd get up, rant for quite a while, until someone from the council, usually the mayor or city attorney, managed to cut them off. Some cities imposed time limits during public comment just to make sure they had a legal way to shut the mikes off.
Honestly, I'm not surprised this happened. I was stalked by a gadfly who was convinced I was the answer to all of his troubles, if only I'd listen to him and his issues. And not that he didn't have issues or a justifiable complaint, but it wasn't truly news. Or verifyable.
Quite frankly, the fact that he was convinced the power lines in town were a form of mind control impugned his credibility. In that case, the very police I was investigating escorted my pregnant self from City Hall to my car twice a month after meetings. It was only about 50 steps, but this guy would stalk my every step, then try to follow me home. I had cops sitting near me in meetings to protect me. I didn't ask for it, but they didn't trust him, and they worried about me, even though I was doing investigative reporting on their department, which was in the midst of a horrible scandal.
I'm not sure what the answer is, but know this: Every elected official takes a risk by putting themselves out there on the dais to make decisions. Some people take those decisions much, much, much too seriously. When that happens, the potential for a mass shooting in a council chamber is there.