The depraved nature of the staging points to an Intruder. Think about it, if someone hit JB and the parents found out, they could have easily staged something else, what parent is going to cover it up with such a violation of their child's dead body?
A mother's instinct would be to preserve her dignity. A blow to the head that killed her could have been set up as a fall in the bathtub. JB wet the bed, PR could have said she didn't want to get in trouble and tried to clean herself up and fell in the tub and cracked her head and died.
There's no reason for all this. It's someone who knew them and hated them.
JonBent was being molested before that night. Burke and JonBent had been found in bed together before by the housekeeper, and was yelled at to get out. There were several books found in John and Pasty's bedroom,along with a dictionary opened to incest, that pointed to her children having some serious emotional and behavioral problems. James Kolar brought several things to the table about children and hyper sexuality and leaves open a good possibility of Burke molesting her. That would be something Pasty Ramsey would never want known.
A neighbor heard a child's terrify scream, that ended abruptly between midnight and two in the morning and it's safe to say it was from JonBent. That is in the time frame of JonBenet eating pineapple and her death.
There was no way John and Pasty could say they found JonBent in her bed molested and dead. They would of been arrested on the spot. An intruder could account for the crime, but why not leave her uncovered for all to see what they did? One of the basic tenets of a kidnapping is take the hostage with you when you leave. Why leave your prize behind? Why take the time and write a rambling ransom note on Pasty's pad of paper with one of Pasty's markers? The longer you stay in the house the chances of being caught rise, and more chances of leaving fingerprints,DNA and fibers behind. Once JonBenet was found in her own home there would be no reason to pay anyone a ransom. Why not take collect the money and dump her somewhere? It was a small amount and John Ramsey had friends ready to get the money from his bank that morning. That was the price they were willing to "lose" on a ransom for JonBent.
JonBenet was wearing brand new size twelve panties, right out of the package, when found. She wore size six and there were quite a few of them,but no other size twelve panties were found in the house by the crime scene technicians. Her blood was on those panties and her blood was on her thighs that had been wiped down. Black fibers that were matched to John's black shirt, that he wore to the White's Christmas party the night before, were found in the crotch of those brand new panties. Someone redressed JonBent before killing her.
Fibers from Pasty's red sweater, that she had also worn the day before, were found on the duct tape found on JonBenet's mouth, and wrapped in the cord around her neck. More red fibers were found in Pasty's paint tote, along with a piece of that paintbrush that matched the one found in the cord around her neck. One piece of broken paintbrush was never found, but cellulose found in JonBenet's vagina was considered to be consistent with that paintbrush.
Now, what are the odds of someone else, wearing the same clothes as Pasty and John, and those things associated with her and the crime scene, molesting and killing JonBenet?
If 911 had been called after the head bash, John and Pasty would of been arrested at the hospital as soon as the previous and the sexual molestation of that night was discovered. They thought JonBent was already dead, but something got their attention and someone made the decision to end her life rather than seek help for her. Someone put a cord around her neck and choked her to death. That may of been, in their mind, the most humane way to end her suffering.
That is why many believe a Ramsey killed JonBenet. There is nothing that points to any one else. It was an unintentional act followed by her murder.