Before I checked a birding guide I thought this was one of the local Evanston (Illinois) peregrine falcons. Now I think maybe it's a Cooper's hawk. It showed up in an Evanston back yard. It took a good hour for it to finish the pigeon it killed, and when it was done there was nothing-- nothing-- but feathers left in the yard. And just for the sake of completeness: these pictures were taken about one or so in the afternoon on November 19, 2006. I haven't processed the photos at all. I haven't even cropped them.