After going through all the evidence available, and conducting interviews with some of the key people involved in the JonBenet Ramsey case, a panel of investigators have landed on a conclusion of how JonBenet Ramsey was killed almost 20 years ago.
"In my opinion, the Ramsey family did not want law enforcement to solve this case, and that's why it remains unsolved," retired FBI profiler Jim Clemente said in the CBS docuseries The Case of JonBenet Ramsey, according to eOnline.
In the final 20 minutes of the special, Clemente, along with world-renowned forensic scientist Dr Henry Lee, former chief investigator James Kolar and leading forensic pathologist Dr Werner Spitz revealed that one person is responsible for the beauty queen's murder. And that one person is her older brother, Burke.
After coming home from a Christmas dinner, John carried JonBenet upstairs to bed while Patsy served 9-year-old Burke some pineapple in the kitchen downstairs.
On Boxing Day, JonBenet Ramsey was found dead in the basement of the family's home in Boulder, Colorado.
Her tiny body was found beaten and strangled, and a two-and-a-half page handwritten ransom note demanded US$118,000.
At the time, the original suspects were her family - JonBenet's father John, mother Patsy and brother Burke.
But in 2008, DNA evidence eventually ruled that all three family members could not have committed the murder and they were cleared. By this time, JonBenet's mother had died from cancer.
The panel involved in the two-part CBS documentary, which aired on Channel 9 on Tuesday night, also allege that Patsy and John made up the entire kidnapping, in an attempt to confuse authorities and save their son, according to The Hollywood Reporter.
On Monday, the final episode of Dr. Phil's three-part exclusive with Burke Ramsey aired in the US, in which Burke insisted there was no possible way he could've been involved in the death of his sister.
"Did you do anything to harm your sister JonBenet," Dr Phil McGraw asked, point blank.
"No," Mr Ramsey responded.
"Did you murder your sister JonBenet," the TV host pushed.
Dr Phil then touched on the theory that Burke's parents, John and Patsy Ramsey, staged an elaborate cover up to protect their only remaining child.
"I don't know what to say to that, because I know that's not what happened. There's been people who have said that it's not even possible for a nine-year-old to do that," he answered.
But the biggest, and most heartbreaking revelation to come from Monday's final instalment was Burke's theory surrounding who he actually thinks killed his little sister.
"I kinda always thought it was a paedophile who saw her in one of the pageants and snuck in [to our house], who knows," he told Dr Phil.
The talk show host then asked if it was possible someone entered the house under the guise of one of the Christmas tours in the area at the time. "It's possible," he replied. "I never really thought about that."
But then he repeated his original theory: "It probably was some paedeophile in the pageant audience."
Critics of the paedeophile theory point to the fact no footprints were found in the snow at the Ramsay's home when the murder happened.
JonBenet's family has been at the centre of speculation surrounding the death of the six-year-old pageant star for almost two decades.
"People still can't get that in their head that we didn't do it," Burke said. "You won't find any evidence because that's not what happened.
"There's been a few people who said that's not even physically possible for a nine-year-old to do that," he added, when questioned about a theory that his parents, Patsy and John Ramsey, covered up the murder to protect him.
But expert Werner Spitz, a retired Wayne State University professor and world-renowned authority on causes of death who was involved in the investigation in 1996, said all fingers still point to Burke.
"If you really, really use your free time to think about this case, you cannot come to a different conclusion," Dr Spitz told CBS Detroit.
"It's the boy who did it, whether he was jealous, or mentally unfit or something ... I don't know the why, I'm not a psychiatrist, but what I am sure about is what I know about him, that is what happened here. And the parents changed the scene to make it look like something it wasn't."
During Burke's first interview with Dr Phil, which aired in the US last week, 29-year-old Ramsey admitted that he was well aware people believed he was behind his sister's death.
"I know people think I did it; that my parents did it," he said.
It is understood Burke took the opportunity to shut down some of the more sinister rumours about his relationship with his sister and mother. He denied accusations that Patsy had anything to do with her daughter's death or that she ever exhibited a violent temper.
But Dr Spitz believes the beauty queen's death was because of a late night confrontation with her older brother.
"They, I mean the police department over there, were quite aware of who the killer is likely to be, from inception almost," Dr Spitz said.
"They came here to Detroit to talk to me, they had me come down there, we talked about the incident ... It was probably the mother or the brother, now it turns out."
Dr Spitz alleged Burke, who now works on computers, as having a "mental problem".
"The brother is not exactly thinking straight, the behaviour is ... of somebody who's got a problem. When I think of putting faeces in the sister's bed ... He was doing that," he said.
Following his "socially awkward" interview with Dr Phil, Burke admitted the reasoning behind his decision not to speak of JonBenet's death was so he could "grow up like a normal kid".
Many who tuned in to watch the three-part interview were quick to notice his rather perplexing, almost happy demeanour.
While reliving some of the gruesome details of his sister's murder, Burke was smiling throughout most of the sit-down - including when he spoke of her funeral.
Some speculated that his smile was because he got away with murder, but Dr Phil was quick to jump to his defence - saying it was nothing more than a "nervous" tick.
"This was not easy for him because he's kind of a quiet guy and kind of a loner," Dr Phil said during a Facebook Live Q & A.
"I spent some time with him, and I have to tell you this is a really nice, young man. I can tell you it's a matter of anxiety. It's just a matter of being socially uncomfortable. I've seen it quite a lot actually. It's nothing weird. It's nothing creepy. It's just nervous."
Burke says, despite the impending 20 year anniversary, that he hasn't lost hope of bringing JonBenet's killer to justice.
"You have to keep he hope alive that it will," he said. "I don't know, you gotta never give up.
"I resent the person who did it. Whoever killed her threw a wrench in my life, my family's life."