In the first trailer for CBS’ new anthology docu-series, The Case of JonBenét Ramsey, investigators revisit the nearly 20-year-old murder, focusing on the frantic 911 call from the girl’s mother Patsy.
The operator, who took the call, says she’s never been questioned by the authorities.
“Twenty years, nobody asked me,” the operator tearfully explains in the clip, which debuted Tuesday. “I think it would have really turned the case around.”
In the new clip, investigators say they plan to further analyze Patsy’s call, stripping the audio and using noise reduction to find a conversation that happened when the Ramseys thought the line was disconnected.
In 2008, the Ramseys were formally cleared in the investigation, though former Boulder Police Chief Mark Beckner said in 2015, “Exonerating anyone … is absurd.”
Pasty died in 2006 after a battle with cancer.
The series will bring together some of the country’s leading investigators to reexamine old evidence and hunt for new clues in the murder of JonBenét.
JonBenét, a Boulder, Colorado, pageant contestant, was found beaten and strangled to death in the basement of her family’s home on Dec. 26, 1996. Her killer has never been apprehended – despite the hard work of countless professionals, as documented in a recent PEOPLE cover story.
Retired FBI supervisory special agent Jim Clemente, aided by forensic scientist Dr. Henry Lee, former Boulder chief investigator James Kolar, forensic pathologist Dr. Werner Spitz, Scotland Yard’s Laura Richards and former linguistic profiler James Fitzgerald, among others, further break new ground with theories about motives and evidence.
WATCH: 5 Clues That Could Reveal What Really Happened To JonBenét Ramsey
CBS also completely rebuilt the Ramsey family home – down to the toys and crime scene tape – for investigators to re-enter the scene of the crime.
“We want to get the truth out, so that JonBenét can rest in peace,” one of the investigators says in the trailer.
More than 140 people have been investigated as possible suspects in the murder.
The Case of JonBenét Ramsey premieres on Sept. 18 on CBS.