Oh, I forgot there haven't been any non-Arab Muslim shooters in US history. Oh wait, yes there have:
http://en.wikipedia.org/wiki/John_Allen_Muhammed
Plenty of Muslims in Southeast Asia. Doesn't mean this killer was one, but it's not as out of the realm of possiblity as some of you would claim.
Anyway, from what I understand this guy was a legal alien resident here in the US. I suspect we'll see the ability for aliens to purchase firearms in US to be revoked sooner than later.