It looks like a Turkey vulture, in the 3rd photo his head appears to be bald Am I the only one who sees that? Wow, what a cool think to see though.

ETA: Nevermind, his head isn't bald xD It's brown. I don't see the prey though. It could be likely you heard his breakfast screeching in distress. There's no doubt in my mind he's a hawk, maybe a Cooper's hawk?