Assuming its a recent photo, isn't it a little late in the season for a Red-shouldered in CT? All things being equal (or equally hard to visually discern) I'd go with Red-tailed.
We often have one or two red-shoulders overwintering here in eastern PA, so I'd guess finding one in CT wouldn't be unheard of. ...
... I don't see a significant amount of white on the back, so I lean juvie shoulder as well.
Yet there is enough white present to be consistent with an intermediate or dark juvenile RTH. There's no shame in uncertainty, you know.
True, but I think a dark morph red tail on the east coast would be even more uncommon than a winter red-shoulder.
Still, I'd be willing to call this one a UR. :-O