Men, your take on this.....

[Major Nikon]

15. I think the answer here is a bit simpler

Some of the things you are mentioning are more of an immediate emotional reaction to some sort of situation. This isn't really what happened with this latest shooter. His actions were planned over a long period of time and at least for him, heavily rationalized.

When you look at other people who do these types of things, inevitably there is some sort of perceived injustice that eats away at them. The law of the instrument binds them to one particularly violent solution. They convince themselves often months or years in advance and the only thing left is the planning and orchestration. I'm sure there's a lot of Stephen Paddocks out there. When someone is found with a massive arsenal, there's a good chance they have moved into the planning stage.