I had a very interesting hand at a large MTT recently.

Party poker monster 100K weekly "freeroll", 4400 runners, 2nd level (blinds 30-60). Fairly passive table preflop. Im doing well so far with 5500 chips (3000 starting stack, avg. about 3700). I have a decent image, though I have taken a few pots with small stabs. The hands I`ve shown down has been solid.

Im on the button with 66.
1 fold, UTG+1 calls, 3folds, CO+1 calls, 1fold. I limp as well, small blind folds, big blind checks. 4way to the flop.

Flop. Pot 270. Flop A64 rainbow. Check, check, CO+1 bet 120, I call, big blind calls, 1fold.
The flop bettor is a solid and tight player, very careful with one pair hands and keeps the pot small with them. He has shown down real values only, so I`m fairly sure he has the A with a decent kicker.

Turn. Pot 630. Turn is another A. Check, bet 250, I raise to 700, fold, CO+1 calls.

River. Pot 2030. River is a J. He checks, I bet 1000 and he raises all in. I have now approx. 3600 left, and he has me covered.

Do you call or fold? He is a good player, so my first thought is that hes on AJ. Comments and thoughts on the hand in general also very much appreciated.

I think he would raise AK preflop, I havent figuered him as very deceptive, but I guess I can`t rule it out to completely.

I think 44 are really what I want to see, but I think he is the careful type of guy that would be really happy to call and show down trips in a pot thats already very large, and not commit (almost) his tournament life with less than the house. Vs a lot of other players I would find the call a lot easier.

I agree with the flop betting, maybe I could massively overbet the turn as well, knowing he would have a hard time folding his trips.
Thx for advice