This is a Cooper's Hawk, an accipiter that hunts only on the wing.  This specimen flew into the back of the garage wall after nailing a mourning dove.  We were afraid it had broken it's right wing (notice the droop).  It had only knocked itself dizzy.  After about 30 minutes of protecting it from our animals, it flew away.  Several weeks later it landed on our pool fence, stared at us for serveral minutes as if to say thank you and then flew away.
Note: there is some question as to whether this might be a Sharp-shinned Hawk. But the Sharp-shinned normally hunts smaller birds. The preferred prey of the Cooper's Hawk is the mourning dove.