In light of today's revelations, I am inclined to think he was giving HUGE clues in those charging documents: he was invited over, they all drank, J and bf started acting frisky. AW maybe was aroused by the scene and felt some type of way that he had no means of, well, you know. They go to bed, he hears it, he gets more and more pouty about it. So in anger snatches ES from bed and assaults/murders her. Based on my observation, he is trying to distance himself ftom actual guilt by bringing up his sister and bf.