It's hard to fathom because it's not true. There's no way anyone in this family strangled JB to death then cracked her skull. You don't become a vicious murderer the way people claim they did in one night like that. This photo proves it wasn't Burke or Patsy or John - http://i.imgur.com/P7ydZLV.png the fingernail marks which are clearly JB's prove she was alive, struggled during the strangling then hit over the head forcefully. It goes against the absurd theory that she was hit over the head FIRST with a flashlight and killed that way, that never happened. It's a lie made up to frame the family. Don't believe the lies.
ABSURD theory? The intruder theory is the absurd one. And no one's claiming anyone became a "vicious murderer."