You'll need to know what cues to look for to identify a dead bird as a crow or hawk. They look alike, except the Fish crow is generally smaller. Are around 15 to 17 inches from tip of beak to tip of tail. Have black beak and legs. Have a tail where each feather is roughly the same length.
Starlings are much smaller, have stubby tails, and can be spotted.
A dead crow. Grackles have more iridescence than crows and their eyes are light. A starling in winter plumage. The spots wear off as the breeding season approaches. In comparison, Turkey Vultures are around 26 inches in length.