B Kean,

I want to understand what happened rather than a Trump-like "murderous loser" dismissal.

It was horrendous. Who knows specifically with this guy, but America has an epidemic of people who are unconnected, lonely, and have lost aspiration. Trump and others collect these souls, feed them, and feed off them.

Put into the mix assault weapons, and we have almost daily occurrences of these tragedies. A chunk of the responsibility is on the people who allow these weapons to be available. The costs outweigh any reason for them.

Best.