prob was his mother tortured him mentally
are we assuming that or is that a known fact?
then again, any guy who would do what he did and suffered from what ever he suffered from most likely had mother issues
and here lies the one thing that is neglected in this whole tragedy
this guy was mentally ill but wasn't one of those dishevled guys you would see mumbling to himself in the subway
he looked like a normal dude who was wearing a mask all this time...kinda like dexter...except for the fact that Dexter is kick ass and only kills for the sake of good and to satiate "the dark passenger"