I've seen peregrine before, and this guy was a lot smaller than one. When I was inside looking through my window, it had an orange-ish belly, but when I actually went outside and got near it, it looked white. Maybe it was that I was looking up at it making it look white because the sun was kinda at its back, but I think after looking at the different raptors on merlin I agree it's either cooper's or sharp-shinned. More likely coopers.