More often than not, I'm inclined to just say "Accipter sp." I don't mind leaving something at genus and the more I talk to other experienced birders about just how tricky it is to tell Sharp-shinned from Cooper's, the more convinced I am that this is the smart choice to make most of the time.

My photos leave a lot to be desired, but based on the field marks that are visible, combined with the very small size of this bird (see the last photo for comparison with Steller's Jay perched nearby), I'm going to take a deep breath and call this one a Sharp-shinned. Contradictory opinions and input happily considered!