I am thinkin Zoebelle is responsible for the murder and is trying to set up SAMCRO to go after Crusoe so he can tell the cops to watch them. I am adjusting my earlier prediction of Piney killing Clay or Tig by seasons end to Piney killing Clay, and I am gonna say its going to happen when Jax says something about Clay being responsible for Donna's death and when Clay pulls a gun on Jax (as he promised he would kill him if he brought it up again) Piney shoots him. Just a guess but it sounds good for now. I do agree that Chuck will figure out that Bobby helped cover up Luann running two sets of books and will tell Clay about it so that he gets on his good side, however Clay will ask Bobby and he will deny it and either Clay or Bobby will end up killing Chuck.