What I remember from playing LA Noire is this mocap is somekind of an "animated texture". Well, if you play the game and look at the face of the character when he finish to talk, you can see a transition, from animated texture to regular texture. I do know that a simple animated texture could not do the job about the going in-and-out tongue for instance, but basically it seems to be something like that, to me. Pretty impressive, even years after the game release, nonetheless !