[Nak]

The turn is definitely a call. You have real outs to win (assuming you are behind) and are getting great odds. The river is closer, but even if you think it's a close situation (I don't think it's that close), you have to err on the side of calling. I have definately seen this situation more than once and the check-raiser had a draw, top pair lower kicker, or even medium pair. Sometimes they will check-raise you because they assume that since you raised, you are betting into them with AK.

Nak