TPTK call or raise river?

[supersub]

Just a few hands into the session. Villain is the only player at the table I dont have stats on, but so far he has been in virtually every pot. No clear picture on post flop play.

Party Poker (6 max, 6 handed)

Preflop: Hero is MP with K[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/heart.gif[/img].
<font color="#666666">UTG raises, Hero 3-bets, 4 folds</font>.

Flop: K[img]/images/graemlins/heart.gif[/img], 8[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
UTG checks, Hero bet.

Turn: 2[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
UTG checks, Hero bets.

River: 7[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
UTG bets, Hero raises...