The Chassidim are too busy disputing how many angels can dance on the head of a pin (while their wives work in a Forman’s to support them!).
I doubt that he was a goth, because the beard and skullcap are not goth garb. I suspect he was a slightly unhinged type who probably felt rejected by somebody in the Christian group (probably a girl that he had made a pass at), went away, studied Islam in OK, and then came home with a perfect rationale for his insanity.
And to think, he could have gone away and grown up instead.
I don't think that defense will work.