Seems like a call to me. If he's a donk he can pot value bet a jack not thinking about what hands call him. Also he could be bluffing there are a lot of draws he might call with on that board that missed.
The turn is defiantly a bet in my opinion. The ace may be "scary" but how many aces are actually in his range?
Value range that beats you -slow played AA (very unlikely), AJ,J8,88,JJ(unlikely) A3s(unlikely),33.
Value range that you beat KJ, maybe worse jacks if he is really bad only thinking about his hand not his hand vs your range.
Bluffing range, T9, T7, 79, QT,Q9, and maybe some other total air hands that just floated you. There are about the same amount of hands in his value range vs him bluffing range but combinatoricly his value range is harder to have.
I think you posted this because you called, he showed some value hand and you were like "I should of known because of his river bet size" maybe you should of but based on the description you gave it might be a good call vs his entire range.
If he never bluffs using that sizing, is a great hand reader etc, that may change things but I can only calculate based on the description given
Hope this helps!
P.S. I'm a bit tired so I apologize if I forgot to list a value/bluffing hand that fits in there.