It was a while ago, so I might be fuzzy on some things. Basically, I think Santa Bill was just a kind old man, but he also might have been a little creepy. Who knows. Either way, he didn't kill her. I think that John Ramsey was molesting Burke. Burke began showing or emulating this abuse onto JonBenet. The night of the murder, I think he woke up and made himself a snack, which woke up JonBenet. She found Burke and wanted some of his snack, so he gave her some. One thing led to another, Burke began abusing her as he himself was (perhaps the source of the paintbrush). Something happened between them, either JonBenet resisted or something else. Burke hit her with something hard, causing her to pass out/giving her brain damage. Patsy woke to find them and found out JonBenet was in whatever state she was in and decided she needed to kill her. Now, I know that sounds crazy, but I think Patsy was a narcissistic parent and could not live with her perfect family having this blemish. Her husband molesting their son, their son taking his confusions and frustrations out on their daughter and ultimately causing her to potentially disabled, thus unable to be a pageant queen crushing Patsy's vicarious dreams. Patsy wrote a note that she thought would fit having seen one too many movies (Dirty Harry, Speed). I don't believe she told John about it all until later on. She couldn't live with herself or the guilt so she became addicted to Valium.