Just an update, they released the guy's name earlier today. He's out of jail on parole after murdering his grandmother with a hammer in 1980...sick guy.
There's a connection to the fire department b/c when his mother died earlier this year, any donations went to them, not the family, so it's possible that was his motivation, though he is clearly sick.
Last I heard, his sister who lived with him was unaccounted for.
Not to start a whole gun control thing, but all of his weapons were obtained illegally.
Stuff like this is a lot crazier when its so close to home.