Photo taken at the Great Swamp in Morris County, New Jersey, March 14th. Canon 40D, 500 MM lens ISO 640 f/4.5, 1/2500 sec, gitzo tripod with Wimberly head. Not sure it this is a Northen Harrier or Broad-winged hawk.
I agree (I think!), a young red-tail, Buteo jamaicensis. Sibley does not show a yellow eye in young Broad-wings. Size would tell (Broad-wing smaller), but impossible to determine from the image. For sure not a harrier- head too large compared to body, body too fat, and it doesn't show the ear patches that a harrier would (like an owl).
The bird looks like a Buteo spp. The pattern of the white marks on the scapular feathers is typical of a Red-tail at all ages. The tail pattern would nicely for a juv. or 1st year Red-tail, and there is enough of the underside visible to suggest the typical Red-tail dark belly-patch.