Who killed JonBenet Ramsey? It's a question that continues to fascinate the public almost 30 years after the 6-year-old was found brutally murdered in her family's upscale Colorado home.

While suspicion has surrounded Ramsey's family for decades, Joe Berlinger, the director of Cold Case: Who Killed JonBenet Ramsey? says the family is innocent and the real killer is still out there. 

A fresh look at JonBenet Ramsey case

On December 26, 1996, Patsy Ramsey called police to report her six-year-old daughter missing. Ramsey had found an unusually long and elaborate ransom note demanding $118,000.

The girl was eventually found murdered and sexually assaulted in the basement - her skull broken, a garrote tied around her neck. The only people known to be home at the time of the murder were Ramsey's parents and her brother Burke.

The bizarre circumstances of the case only raised more questions. If this was a kidnapping, why was JonBenet murdered? How did the ransom note's author know the amount of John Ramsey's bonus?

In the media frenzy that followed, John and Patsy Ramsey became the prime suspects - and, to this day, many believe they are guilty.

In an interview with the New York Post, director Joe Berlinger said the case was tainted by faulty investigative work, which led to plausible suspects being ruled out. Berlinger pointed to the possibility of a pedophile targeting JonBenet, who was a child beauty queen.

“Sadly, there are a lot of people in the world who are attracted to little girls, and can do horrible things to them," Berlinger said. "[An intruder] is a much more plausible scenario than the family having been involved, if you look at some of the basic facts in the case.”

Family innocent?

While the case is considered unsolvable by many, Berlinger believes the real killer is out there - and can be found still.

"I am firmly convinced that the Ramsey family is innocent. And I am also firmly convinced that this case can be solved, if the Boulder Police Department finally does what it's supposed to do," he said.

In 2008, district attorney Mary Lacy controversially cleared the Ramseys, over the objections of police who said new DNA evidence was not exculpatory. Patsy Ramsey had died from cancer in 2006.

John Ramsey, now 80 years old, has maintained his innocence. He insists his daughter's murder, which remains under investigation by Boulder Police, can be solved with more sophisticated DNA analysis.

Meanwhile, Berlinger is hopeful that the new Netflix series will finally clear the Ramseys and put pressure on the authorities to perform a thorough review.

“I think all suspects now have to be put back on the table, including the Ramseys. And they would be the first ones to say, ‘Sure, put this back on the table, but let’s do the DNA testing.’ This is not trial by television. I don’t want to do to people what was done to the Ramseys,” Berlinger added.