It always surprises me that people forget the MOST OBVIOUS reason "kidnappers/intruders" had to be brought in by the Ramseys:
Prior sexual assault.
For the sake of argument, consider the following as possible:
They knew JonBenet had been molested. Signs of a child being molested are often presented to the caregivers: from a child's overtly sexual behavior, blood in her panties, etc.; Patsy even told a close friend (Pam Archuleta) she was upset because JonBenet was "flirting" and "too friendly". If the sexual abuser were one of the adults in the home that night, that opens up other possibilities, as well.
Patsy's 3 calls after hours to Dr. Beuf on Dec. 17th have never been explained by either him or the Ramseys. Patsy told LE she didn't remember.
The Ramseys knew this serious sexual abuse would be found by medical staff if they took the child to the hospital--it was 1996 and both Ramseys were intelligent, well-educated adults in America, so that's a no-brainer.
And how were they going to deal with that, since they also knew she wasn't going to get up and walk away from this head bludgeoning?
There is no question the child had healing vaginal injuries found at autopsy, with evidence of long-term sexual abuse. No medical expert disputes this--NONE. The only equivocating ever done by any medical expert was what caused those injuries. IDI are compelled to come up with various scenarios to explain it away as innocent and not sexual assault, but that requires believing some intruder coincidentally decided to jab the child's vagina with a paintbrush for some other odd reason, after attacking her viciously for no reason anyone can explain EXCEPT SEXUAL ASSAULT.
So, to continue with the argument:
The sexual abuse of a six year old is statistically much more likely to be committed by close relations who have access to the child.
Incest is the biggest taboo in our society, and Patsy, being from West Virginia, would be very likely to know this herself.
As a prominent, proud family, with a lot to lose socially and professionally, having the brutal physical abuse of a head blow that put her into immediate unconsciousness might be easy enough to lie about; but having it discovered that their little beauty queen was being sexually assaulted by one of her own family, as well, would be great motivation to attempt a cover up and then use all their powers and money to dig their way out once they got themselves out of Dodge--so to speak.
I don't believe they were all alone in their decisions that night, either. There is that "lost cell phone" story provided by Patsy to LE in 1998--as perfect a performance of obvious lies as I've ever seen. Since Hunter buried the subpoena to get those phone records, and to our knowledge they've never been subpoenaed, we only have that mysteriously lost cell phone with the blank record for the month of Dec., 1996; the Ramseys "turned over" that one month's record to LE a year later--but only that month's record, with no follow-up by LE other than Thomas going to the cell phone co. to obtain it and asking an employee if there were active calls on the records in the months before--yes, there were. How about after that month? Did the Ramseys cancel the "lost" cell phone after it was "lost"? I've never even heard or read of LE asking. Ha.
This is my personal "harp" in this case: with a few simple subpoenas, every single one of those questions could have been answered. If the phone was lost, if it was canceled as "lost" by the Ramseys before the murder, if there were no phone calls on it after the murder, etc., how easy to move on. Instead we have more Team Ramsey ridiculous "coincidences" to excuse the unimaginable obstruction of evidence collection in a child murder case, by the parents of the victim, by the DAs who should have been demanding that evidence, not blocking detectives from getting it.
I cannot imagine how anyone can look at the autopsy evidence of prior sexual assault/molestation, the blatant obstruction of the investigation and evidence collection by the parents and Team Ramsey--which included 2 DAs, sadly, and not at least recognize that the Ramseys look guilty because they did every single thing they could to make themselves appear guilty--and because the evidence still leads only to them, the only people inside their home that night.
Well, these are just my thoughts on evidence that is critical in explaining what the parents were thinking and what motivated them to do what they did that night: an intruder was the sexual assaulter, not them, the good Christian, American Dream family.
But the paintbrush used on the child was used to cover up that prior molestation, not as an instrument of molestation. It was in the paint tray in the basement where the child was laid on the floor and then strangled to death with the ligature tied to the broken paint brush shaft.
This is KEY. What was done to the child by that paint tray, with that paint brush, was done to HER, not to hurt her parents. No "sadistic pedophile" used a stun gun on her because she'd have screamed bloody murder and her family would have been awakened.
Do some online googling and you'll see what happens when a stun gun is used on people. I can't imagine a sadistic pedophile so clever as to leave only degraded particles of DNA in a house in which he'd spent hours roaming around, murdering a child, writing a ransom note, etc., wouldn't have known his stun gun was loud and would produce screams, not unconsciousness.
And no, he didn't put duct tape over her mouth to keep her quiet: she had saliva dribbling out of her mouth down the side of her face after she was unconscious, so the duct tape wasn't on her mouth before the attack.
As for the strange, moving lights in the dark kitchen: if the initial attack of the head-blow happened upstairs, that would explain why a flashlight was used to move around the first floor and into the basement. The house had windows which could be seen through by the neighbors, so lights which were usually turned on around the home weren't on late that night, one near neighbor noticed. Instead, the Maglite was used, which JAR had given to JR and which was a common brand used by the private plane owners of that time because of its reliability and durability.
Remember the basement was dark, too.
So there is evidence that the attack originated in JonBenet's bedroom: her blood was found on her pillowcase, according to the questions asked of Patsy by Haney in 1998. (Did she have nosebleeds? When were the sheets/pillowcases last changed? Etc.) The obvious activity around the area of her bedroom is chaotic: drawers left open in her and JAR's rooms; diapers hanging out of the cabinet in the wash area outside them; a kitchen paring knife left on the washing machine; Burke's soiled pajama bottoms left in the floor of JB's bedroom; the bed pillow on the bottom of the bed, her pj top lying askew at the top; the curtain pulled over the headboard; etc.
Then she had to be moved the basement for the strangulation, which was a horrifying way to attempt to cover up what had already happened to the poor child--ongoing sexual abuse, incest, bludgeoning. It was all just a family spun out of control to a level I don't believe they ever expected.
Personally I don't believe Burke could have carried JonBenet's limp body downstairs himself, and certainly not while holding a large, heavy Maglite. So...yes, in this theory, at least one other adult had to be involved, to carry out the remaining atrocities on the child, if not the initial attack.
Add in the ransom note, and this convoluted crime was a lot for one person to do alone, and impossible for Burke alone, IMO. Whatever their intent, whatever kinds of personal demons were at work that night in that family, I believe they acted as a family.
And that's as best as I can put all the known evidence together to determine the elements of this awful crime.
Sorry this is so long. Just so much to explain....