As the ransom note demanded $118,000 (£89, 903) - the exact amount made by the Ramseys in bonuses that year - investigators suspected that JonBenét’s murderer was someone very close to home. For several years, JonBenét’s mother and father were lead suspects in the case but in 2008, they were cleared via a DNA sample taken from their daughter’s clothing. JonBenét’s mother, Patsy, had died of cancer two years earlier, in 2006.

Prosecutors said they were "deeply sorry" for putting the family under a cloud of suspicion for more than a decade.

The six-hour series will bring together several individuals involved with the initial murder investigation, including former New York City prosecutor, retired FBI supervisory special agent and profiler Jim Clemente; world-renowned forensic scientist Dr. Henry Lee; former chief investigator for the District Attorney in Boulder, Colorado, James Kolar; leading forensic pathologist Dr. Werner Spitz; and retired FBI supervisory special agent and forensic linguistic profiler James Fitzgerald.

Reporters in the documentary will also interview the operator who took the initial 911 call.

“In twenty years, nobody asked me [what happened],” she says in the trailer. “I think it would have really turned the case around.”

Making a Murderer fans: get set for a new real-life crime series