Also what court in the world would take forum posts as serious evidence?
It's been done. There are difficulties with it, of course.
And what right minded person taking that story for face value would want to prosecute?
Well, assuming we believe the good Thor, he would be saved by the self-defence aspect of the story. But a proper investigation wouldn't just take his word for it as described, "face value". And by "proper", I mean "anything other than bumfuck Keystone Kentucky cops", apparently.
and also, "cleaning" the scene, and a gun you have the serial number filed off of? You're all kinds of fucked up, dude. Real talk.