[mdob]

Well, if you're certain he has KK after the turn bet, I think it's an easy raise as villain will fold KK more than the necessary 20%-25% of the time.
I don't, however, agree that KK is a lock. Is AA ridiculous? AK is also still a possibility (as is, say, QQ or JJ). KK is the only hand (OK, QQ, too) you want to raise, but I think there are plenty of other hands he could have.
Last thought: Is he a good player, or just a TAG? With KK, this seems like a wa/wb situation for him. Would he take the standard c/c line here on the turn if he recognizes that? Would he think you'd realize that's what he's doing, etc.?