Thornton Omar Sharriff Kills 9 in Connecticut

another muslim name

I don't find anything in the article to suggest that he did this because he was a Muslim.

We don't even know that actually.

Thornton, who is black, had complained about being racially harassed at work. Thornton brought his complaints to his superiors, who did nothing about it, she said her daughter told her.

You're right, technically but I think this is a clue to what it might be. Add to that the fact that he declared bankruptcy in 2000 and lost is commercial drivers license; I think the guy just wanted to take someone with him on his suicide rant.