I think once you made the decision to raise the flop and bet the turn you were in for that last $87. Since he called you that far and based on his prior play you have to know that he's going to call or bet the rest of his cash. Even if you put out a blocking bet he's going to probably raise all-in here.

But maniac aside I think you have to call here anyway. As I see it the pot is over $180, and you're pretty much pot-committed yourself here. The A isn't much of a scare card because you put him on a K, and if he's on AK he's aggressive enough to re-raise you on the flop or turn. If he is dumb enough to play a single A all the way to the river then it becomes almost impossible to put him on any hand, let alone a hand with an A. Besides, if he had an A wouldn't he be afraid that the all-in might scare your K off (and it's pretty clear you have a K here). With the pot laying you 2-1, no obvious draws and TP2K I think this is a must call situation.

This is one of those hands where you need to decide on the flop (if not preflop) whether it's worth putting most of your chips in the middle. You're not going to get much more information about his hand and you wouldn't want to give cheap cards even if he'd let you (which I doubt he would), so if you have a read then use it and stick by it to the end, if not drop it then and there.

I agree with iceman here, I'd check-call just about any size bet on that river. Either he had you beat all along with something like a low set (or a fortunate turned A6) or you're ahead, I really can't see how he can have caught a river ace unless he was drawing to a flush, and if he HAS caught his ace or he's been slow playing all along, I guess there's a good chance he'd make a milking bet rather than a powerhouse. I think you win often enough to call this down.

Monk
xxxxx

But if he has a weaker K, he probably won't call a really big raise here, and that's basically the only hand you've got beaten. I say you make a value bet here. But you really do have to call him down after begging him to bluff the scare card like that.