It was a crime that shocked the world and one that has endured in its mystery ever since.
Six-year-old beauty pageant queen JonBenet Ramsey was found bludgeoned and strangled to death in the basement of her home in Boulder, Colorado, on Boxing Day in 1996.
For several years after it happened, the little girl's parents John and Patsy Ramsey were suspects until they were eventually cleared in 2008 and to this day, no-one has been convicted.
But today, startling revelations have emerged that an American grand jury voted to formally charge the parents - but prosecutors refused to press charges.
In a remarkable twist to the story that was one of the 'Nineties biggest talking points, it was revealed that a Colorado grand jury voted to indict the Ramseys in 1999 on charges of child abuse resulting in death - a crime that can carry up to 48 years in prison.
But sources, including members of the grand jury, told the Boulder Daily Camera that District Attorney Alex Hunter refused to sign the indictment vote, apparently believing he could not prove the case beyond reasonable doubt, and never revealed the result.
Instead he announced the end of investigation, saying: "I and my prosecution task force believe we do not have sufficient evidence to warrant a filing of charges against anyone who has been investigated at this time."
It is unclear whether the DA acted properly in not signing the indictment.
However, one expert told the paper that in her opinion proper legal procedure would have been to sign the document and file it with the court before going to open court to dismiss the charges.
Hunter, who left office in 2001 after 28 years as Boulder County's district attorney, issued a statement, saying: "Colorado statutes, the ethical canons which govern the practice of law, and the Boulder District Court's oaths.
"Instructions and orders in the JonBenet Ramsey grand jury proceedings, are well established and absolutely clear with respect to the various participants' legal obligations, duties and responsibilities, including the inviolate secrecy of the proceedings and the differing burdens of proof applicable to jurors and prosecutors.
"As the duly elected district attorney at the time and as an officer of the court then and now, I must respectfully decline further comment."
On Christmas Day of 1996, the family received a ransom note saying that JonBenet had been kidnapped and were demanding $118,000 - the amount of a bonus Mr Ramsey had recently received - or else she would be beheaded.
But it was not long before her body was found in the basement of the house. Her wrists were tied above her head, and she had duct tape over her mouth.
An autopsy report revealed that she had been strangled and bludgeoned to death. Within hours, the Ramseys themselves became the chief suspects of the investigation and police were later criticised for losing focus of the crime scene and other leads by concentrating on the family - including JonBenet's brother Burke - instead of following up other leads.
For the next 12 years, the blame for their daughter's death - who was given the name Little Miss Sunshine - lay largely on their shoulders as they fought to clear their name and find the real killer.
Eventually, Boulder district attorney's office completely cleared the Ramseys of any wrongdoing in their daughter's slaying and issued an apology in 2008.
Since then, John Ramsey has kept the memory of his daughter alive, despite losing his reputation, a thriving business and Patsy to ovarian cancer in 2006.
Mr Ramsey eventually found happiness through his relationship with fashion designer Jan Rousseaux, who he married at a private ceremony in Charlevoix, Michigan, in July 2011.