I'm going with the "Gay" angle. That train conductor that derailed that train is "Gay". That German airline pilot that crashed his plane into the ground was reported to also be "Gay". Most of the Serial killers in our history were "Gay".
I'm betting it's the normal expression of homosexual murderous rage at people who say their lifestyle is sinful.
I said he’s probably gay on another post. Thats were my money stays until proven he isn’t.