More coming to light on this...
I've seen some articles that:
a) the shooter frequented the club over the past few years
b) the shooter had a profile on a gay dating site
To me, this is looking more and more like a kid whose orientation was at odds with his home life, and that he felt the need to "purge" himself of this sin, and his answer to it was to basically go full blown ISIS style to get into heaven as a martyr (as he saw it), by freeing others he thought of as sinners. It's a sick ideology, but I do believe this begins to make sense of why he did what he did. No doubt the father's religious oppression played into this.
Sorry, but the dad consistently spouts anti-America crap, so he should be stripped of his naturalized citizenship, and sent right back to Afghanistan. (at the very least)