The day after Christmas in 1996, John and Patsy Ramsey woke up to find their six-year-old daughter JonBenét, a childhood beauty queen, missing from the family home in Boulder, Colorado.

A handwritten ransom note was found on the stairs near the kitchen demanding $118,000 – John’s exact bonus that year. Seven hours later, John discovered his daughter’s lifeless body in a small room in the basement.

The case has gripped the nation for decades.

Now, 28 years later, John Ramsey still hopes his daughter’s killer will be caught. He believes new DNA technology could help police reinvestigate the murder of JonBenét, a case that drew global attention.

JonBenet’s autopsy revealed that she had been sexually assaulted and strangled, and her skull was fractured. Unknown DNA was found under her fingernails and in her underwear.

The Ramseys quickly became suspects, even though there was no evidence linking them to the crime.

The Ramseys have consistently maintained that they were not involved in JonBenet’s murder. However, it took the Boulder District Attorney’s Office twelve years to fully exonerate the Ramseys and their son Burke.

As weeks passed with no arrests made in the case, a media frenzy began to unfold, fueled by nonstop tabloid images of JonBenét competing in beauty pageants.

A number of suspects emerged, including a man named John Mark Karr, who confessed to the murder in 2006. However, because his DNA did not match the evidence, he was never charged. The case remained open.

To this day, John Ramsey believes that a shadow hangs over his family because there are still people in the country who believe that he and his wife Patsy, who died in 2006, were responsible for the murder of JonBenét.

“There would still be 5 to 10 percent of the population that thinks, ‘Yes, it was the father or yes, it was the mother,'” John said.

Despite the loss of his wife and daughter, John Ramsey remains steadfast. He has since remarried and finds solace in his children and grandchildren.

John is also working with director Joe Berlinger on a new documentary streaming on Netflix called “Cold Case: Who Killed JonBenet Ramsey?”

“We believe the crime can be solved,” Berlinger said. “We want to pressure the Boulder Police Department to do DNA testing.”

The documentation revisits the early phases of the investigation. From the beginning there were questions about how the police handled the investigation.

“Early on they were preoccupied with the crazy idea that the parents were responsible,” Berlinger said. “They have tunnel vision, so they don’t try to explore all the possibilities.”

The crime scene is also under observation because it may be contaminated, which, according to Berlinger, poses additional challenges.

People streamed through the house, from the kitchen to the living room.

The Boulder Police Department told Nightline: “We are committed to pursuing every lead. We continue to work with DNA experts and our law enforcement partners across the country until this tragic case is solved. This investigation will always be a priority for the Boulder Police Department.

John Ramsey is confident advances in DNA technology can help identify his daughter’s killer.

“This genealogy research has solved a number of old, unsolved cases,” said John Ramsey. “Let’s do a reverse family tree and see if he (the killer) had a relative who lived in Boulder in 1996. That’s what we ask the police to do.”