Good post. If you are correct that only a high energy swing, with some object, caused this head injury, then, I have to rule out John or Patsy as the one inflicting the injury. I simply can't grasp Patsy or John, violently, swinging an object at their daughter's head in that manner. I think this is why ST tried to imagine a scenario where JBR was slung against something when Patsy and JBR were involved in a scuffle...I don't think he could grasp Patsy deliberately swinging an object at JBR knowing that it would most likely be fatal. If Patsy is involved with the head injury, it had to be an accident precipitated by a physical confrontation of sorts. I'm still not convinced that a "high-energy transfer" could not occur with a person's head being whipped by slingng that person or that person resisting someone pulling on them and then the grip being lost with the result that the victim falls back with force. The human head is heavy and, with a sudden whipping action, I'm not sure you couldn't punch out a piece of skull if everything was just right. But, I'll concede that a bat, golf club, flashlight, etc., is the most likely cause of the skull fracture. This is why I've always thought that BDI is the most likely scenario. But even here, it's going to take an effort for Burke to wield a "high-energy transfer". I'd be more inclined to believe a bat was the object that caused the injury.