Tough river decision

[Roy6]

Villain is 51/1.8/0.53 after 170 hands.
He seems an easy target but he's a rather annoying player for me.
I once caught him, he donked with KJ UI on both flop/turn on a low board.

I've got ATo in the cutoff, and only he (in BB) calls my raise.

Flop is T [img]/images/graemlins/diamond.gif[/img] J [img]/images/graemlins/heart.gif[/img] Q [img]/images/graemlins/club.gif[/img]
He checks and calls a bet

Turn is 9 [img]/images/graemlins/heart.gif[/img]

He checks, and I check through (?)

River 5 [img]/images/graemlins/club.gif[/img]

He checks, I bet, he raises, ???