It's the murder that has gripped a nation for more than 20 years.
JonBenet Ramsey was just six when she was found bludgeoned and strangled o death in the basement of her family home on Boxing Day in 1996.
And now convicted paedophile, Gary Olivia, is reported to have confessed to killing the six-year-old.
The 54-year-old is said to have admitted to killing JonBenet "by accident" in letters to a school friend.
The young beauty queen was found by her father the day after the family reported her missing.
They had received a two-page ransom note asking for $118,000 in exchange for the child’s safe return.
But, eight hours later, her dad discovered his daughter’s body under a white blanket with a cord twister round her neck in the basement of their family home.
Her wrists were bound and she had been gagged with duct tape. She had also suffered a fractured skull.
What happened on the days before her death and who were the initial suspects?
Christmas Day had been an exciting time for the Ramsey family.
Father Christmas had delivered a new bike to delighted JonBenet and she tried out her present that day - it would be the last time she rode it.
Along with her dad, John, mum, Patsy, and brother, Burke, who was then nine, JonBenet went for dinner at at family friend's.
The six-year-old was tired after her day of fun and was carried upstairs, sleeping, by her father when the family returned home later that night.
This would be the last time anyone in the family saw her alive.
Just eight hours later her tiny body was discovred in the basement of the family home.
As the only people known to be in the house at the time of her killing, JonBenet’s parents Patsy and John were soon under suspicion.
John, a computer executive, and Patsy, a former Miss West Virginia, went on CNN to insist they had nothing to do with their daughter’s tragic murder.
Within two weeks of the girl’s murder, police considered her parents were unlikely to have committed the brutal crime.
They were cleared of any involvement in 2008 with the help of DNA technology.
The ransom note
The ransom note discovered with JonBenet's body was handwritten on pages ripped from a notepad her mother had kept by the telephone.
Theories circulated suggesting the ransom note was actually written by the little girl’s mum.
The sum asked for was the exact amount JonBenet's father had received in his work bonus that year.
Experts also claimed there was a connection in handwriting style between Patsy and the note-writer.
Cina Wong examined the note for three weeks in 2000, comparing it to examples of Patsy Ramsey’s writing.
Wong claimed there were over 200 similarities.
Suspects
JonBenet’s older brother Burke was nine at the time of her murder.
Theories emerged that he could be the killer and that their parents covered up JonBenet’s death to protect their son.
He was cleared by DNA evidence.
Around the 20th anniversary of JonBenet's death, her brother spoke out for the first time in 2016 on US talk show Dr. Phil.
He said: “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's not even physically possible for a nine-year-old to do that,” he said.
“Like you won't find any evidence because I didn't do it.”
John Ramsey revealed later how he tried to hide the allegations splashed across the papers from his young son.
"The headlines from a tabloid screamed out that Burke had done it," he said in 2008.
"She [Patsy] dropped her produce and rushed Burke out but the damage had been done."
In 1999 a jury voted to charge JonBenet's parents with child abuse that resulted in the death of their daughter.
The charges were never pursued and DNA evidence later also cleared them both.
Patsy Ramsey died from ovarian cancer in 2006, 10 years after her daughter's murder, aged 49.
Burke Ramsey said he chose to finally speak out about his experience because: "I know people think I did it; that my parents did it. I know that we were suspects.
"I want to honour her memory by doing this interview. I don't want anyone to forget."
He told Dr Phil that “I kinda always just thought it was a paedophile who saw her at one of the pageants, snuck in, who knows?”
The district attorny apologised to JonBenet's parents in 2008 and exonerated them of any wrongdoing in relation to their daughter's death.
What other theories are there?
DNA evidence taken from under JonBenet's nails at the scene cleared both her parents and her brother.
It revealed the little girl had probably clawed at her attacker in the strugle.
But the DNA did not come from anyone who had been at the scene, her family or anyone who had handled her body.
It was from an unknown male.
DNA, believed to be saliva, was also found in her underwear.
The intruder theory
With all of JonBenet’s family cleared of her murder, another possible explanation was that an intruder forced entry into their house and carried out the killing without anyone hearing the horrific crime take place.
The CBS documentary examined a broken window, which could have been used to access the basement where JonBenet was found.
JonBenet’s dad said he broke the window some time before the murder when he was locked out of the house.
Boulder Police Department initially ruled out anyone gaining entry through this window.
But on the other side of that broken window was a suitcase, where police found a footprint.
It's thought that an intruder could have possibly stepped on the suitcase to get back out of the window, leaving the footprint behind.
The footprint was from a pair of Hi Tec boots, which the family's lawyer insisted that is proof that an intruder got into the house.
The lawsuit
Burke Ramsey filed a lawsuit against CBS for a docu-series made in 2016, 20 years after his sister's murder.
He sued the US broadcaster after their programme suggested he killed his younger sister.
CBS officials requested the $750 million case be thrown out but a judge refused.
According to Burke, his reputation was ruined after the two-part show - The case of: JonBenet Ramsey - concluded he was JonBenet’s killer.
While CBS argued that the programme included a clear disclaimer which said: “The opinions and conclusions of the investigators who appear on this program about how it may have occurred represent just some of a number of possible scenarios.”
However, the judge, Michigan 3rd Circuit Court District Judge David Groner, said that wasn’t enough to throw out Ramseys case.
He added: “This Court does not find that the 'disclaimer' at the beginning and end of the program negate the docu-series potentially defamatory meaning.”
According to local paper The Daily Camera, the case has since led to courts in the Ramsey family’s hometown of Boulder, Colorado, to request vast numbers of files from the police investigation.
The police are fighting the subpoena on the basis that “disclosure of police investigative files will adversely affect the investigation."
The case is still in the pre-trial stage.
The confession
Convicted paedophile Gary Olivia has reportedly confessed to the killing in letters sent to a former school friend.
He is said to have admitted to killing the child beauty queen "by accident".
The 54-year-old is serving a 10-year sentence for child abuse image charges.
In one of the letters, Oliva allegedly wrote: "I never loved anyone like I did JonBenét and yet I let her slip and her head bashed in half and I watched her die.
"It was an accident. Please believe me. She was not like the other kids."
In another letter, Oliva is alleged to have said: "Yet by accident she died and it was my fault."
The Boulder Police Department is investigating.