I think he's on one of the following

AJs, AJo, ATs, QJs, QTs, JTs

He didn't raise from early position preflop so unlikely he's on AKs AKo or AQs. AQo only gives him a gutshot on the turn so why lead out? I think the jack helped him. I think he paired his J and is on the flush draw as well, or picked up a gutshot to go with his flush draw.

I don't think he's on KJ because the flop c/c is too strange.

I call the turn and raise the river but fold it to a reraise.