Don't forget the history of the 20th Century where such "outlier events" included 100 million previously disarmed people killed by Communists running their countries, and the Left likes to remind us of the small death tolls in right wing countries, although many of those were fighting communists. See also the WWI era Armenian Genocide which was so ignored by the rest of the world it convinced Hitler he could do as he pleased.
I'd grant you Imperial Japan, but I wasn't talking about them or what they did, which you fail to notice was done to others, non-Japanese peoples. Like how I noted the Armenian (and lessor known but still significant Greek) genocides by Muslims running Turkey were also of a different nature.
Meanwhile, you might want to try a legitimate reply attacking what I said, not myself.
I think there are real things that could be done short of a total ban, but the issue in the US it's a constitutional right so it's hard to restrict in any sensible way and it's politically impossible to amend.
As it is, the policy question is accepting the tradeoff of the right to bear arms vs. rare, but extremely awful death of school children. I'm not really taking a strong position, I think that's just the reality of it.
https://www.lesswrong.com/posts/PeSzc9JTBxhaYRp9b/policy-deb...
https://slatestarcodex.com/2014/08/14/beware-isolated-demand...