I just had a thought about the murder and want to run this by others. Suppose JR had been sexually molesting JB over an unknown period of time prior to 12-25. Knowing the family is about to depart on a long vacation, during which time he will not have access to her, JR feels the urge to molest her again on the night of 12-25, prior to the vacation. For privacy, JR has been taking JB down to the basement where the molestations take place. This had happened on multiple occasions before but this time something happened different than all previous times. This time PR discovered/caught JR in the act. Maybe JR thought PR was asleep and she wasn't. Maybe PR had suspected for some time and, finding JR missing from their bed, went to find him and ended up down in the basement? The key part of this theory is PR discovers the abuse, but her reaction to it is to, instead of holding her husband responsible for his actions, is to strike her daughter over the head with an object in complete emotional rage over what she has discovered and to, in her own head, hang on to her denial that anything is going on. Can you envision it? I can, but it is just a theory.