[n.s.]

I'd just go ahead and cap it. I doubt this guy is going to fold an overpair, he might lose his nerve and check-call the river, and if he's got something like KK or QQ, an overcard on the river might slow him down (if he's a bad hand-reader).

Plus if he's got AA and he's one of those guys that refuses to ever put anyone else on quads, then you might get to cap both turn and river (unlikely, but it could happen).