Cooper’s Hawk?

I found this bird having its breakfast in my garden this morning. If was not frightened one jot of my dog and stood guard over its kill so I brought her in!
Is it a Cooper’s hawk? It has striped tail feathers and white spots on its wings, pale chest. I can’t really gauge how tall it is as I don’t want to get too close! I didn’t think they were native to the UK though so is there anything else it could be?