They were on the hunt for a monstrous child killer. Someone so depraved they would murder a six-year-old girl and leave her body in her family's basement, with a nylon cord around her neck, her wrists tied above her head and mouth covered by duct tape.
Soon after the killing, Boulder District Attorney Alex Hunter fronted a media pack, warning the person or persons who committed the crime that they would "see that justice is served in this case and that you will pay for what you did".
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Documentary names suspect in JonBenet Ramsey cold case
Forensic experts have re-examined the death of the six year-old pageant queen and claim they've found the most likely suspect.
But what if the person who killed JonBenet Ramsey was not a murderous paedophile, but a nine-year-old boy?
That's the conclusion of a new documentary The Case Of: JonBenet Ramsey, just aired on Channel Nine, which presents evidence the 1996 killing of the little girl and child beauty pageant star began with an angry sibling and ended with an elaborate cover-up by her wealthy parents.
"It's not a foreign faction that committed the crime," forensic linguist Jim Fitzgerald said. "To me this crime happened within the four walls of this house."
The television investigation concluded the killer was probably JonBenet's older brother Burke Ramsey (who was just nine at the time of her death).
The theory is that Burke may have been put out by the attention given to his younger sister, who had won a string of child beauty pageants in which her mother, Patsy Ramsey, entered her.
A family friend, Judith Phillips, said she'd been told Burke had hit JonBenet with a golf club about a year and a half before she died.
![Burke Ramsey being interviewed by Dr Phil.](/web/20160921201738im_/http://www.smh.com.au/content/dam/images/g/r/k/r/f/d/image.related.articleLeadwide.620x349.grkr84.png/1474436307023.jpg)
"I think Burke had a bad temper. It's like he had a chip on his shoulder," she said.
On Boxing Day 1996, JonBenet was found dead, struck on the head and strangled, eight hours after she had been reported missing.
![John Ramsey looks at his wife, Patsy, as they appeal for more information about the death of JonBenet Ramsay in 1997.](/web/20160921201738im_/http://www.smh.com.au/content/dam/images/g/q/v/n/w/7/image.related.articleLeadwide.620x349.grkr84.png/1474436307126.jpg)
Her mother said she found a ransom letter on the kitchen staircase demanding $US118,000 for her daughter's safe return.
James Kolar, a former investigator for the Boulder District Attorney, said he believed that when the Ramseys came home on Christmas night, JonBenet was put to bed while Burke was served tea and a bowl of pineapple by his mother.
![A Boulder Police Department detective leaves the home of John and Patsy Ramsey in this photo from January 3, 1997.](/web/20160921201738im_/http://www.smh.com.au/content/dam/images/g/q/v/n/w/o/image.related.articleLeadwide.620x349.grkr84.png/1474417845959.jpg)
Kolar said that at some point Patsy roused JonBenet to go to the toilet so she would not wet her bed.
He said JonBenet may have gone downstairs and taken a piece of pineapple from the bowl.
![The grave of JonBenet Ramsey in December 1997.](/web/20160921201738im_/http://www.smh.com.au/content/dam/images/g/q/v/n/t/u/image.related.articleLeadwide.620x349.grkr84.png/1474417845959.jpg)
"I think that if Burke was upset about circumstances or Christmas presents he may have been upset about her trying to snag a piece of pineapple," he said.
"Out of anger he may have struck her with that flashlight."
![<p>](/web/20160921201738im_/http://www.smh.com.au/content/dam/images/g/r/k/r/f/w/image.related.articleLeadNarrow.300x0.grkr84.png/1474436306785.jpg)
The documentary experts theorise what happened next in response to the "spur of the moment" killing was an attempt by John and Patsy Ramsey to protect their surviving child.
Former Boulder Police co-lead investigator Steve Thomas, who conducted the first official interviews with the Ramseys, said he believes Patsy was the author of the ransom note.
"We know that was her pad. Her fingerprints were on that pad. The sharpie pen, we located it, and ink matched it to the ransom note, which had handwriting characteristics that some experts said were remarkably similar to Patsy's," he said.
Burke Ramsey, now 29, did not speak to the documentary team, but was recently interviewed by television host Phil McGraw, known as Dr Phil.
"Did you do anything to harm your sister JonBenet?" Dr Phil asked.
"No," Burke Ramsey responded.
"Did you murder your sister, JonBenet?" the TV host asked.
"No," he said again.
At one point in the documentary, aired on Monday and Tuesday, forensic pathologist Dr Werner Spitz asks what could be accomplished by "bringing this case back to life".
JonBenet's mother died of ovarian cancer in 2006 and, even if it was conclusively proven that Burke was the killer, Colorado's minimum age for prosecution is 10. He was nine years and 11 months when his sister died.
Colorado defence attorney Lisa Polansky said: "The science behind it of course would be that a child under 10 is not psychologically able to commit a crime."