The murder of 6-year-old beauty queen JonBenét Ramsey remains unsolved, but a team of investigators vows to change that in a new series. CBS

It’s been nearly two decades since six-year-old beauty queen JonBenét Ramsey was murdered in her Boulder, Colorado, home on Christmas Day, but a new series promises to try to catch the murderer by examining new evidence and talking to new witnesses.

The three-minute trailer opens up with a statement from JonBenét’s father, John: “I want to address directly that I did not kill my daughter, JonBenét.” Her mother, Patsy, who died in 2006 from cancer, adds, “God knows who you are and He will find you.”

The trailer calls JonBenét’s death “the murder transfixed the nation” — and it's true. Even after all this time, people are still captivated by the homicide. “This little girl's homicide to this date has not been resolved. In my opinion, I think we can change that right now," retired FBI special agent James Fitzgerald says in the clip.

“We hope to get the truth out about how she died. She’s not gotten justice yet,” Jim Clemente, an FBI agent who previously worked on the case, says. “My experience as a prosecutor in New York city helps me understand how you put together a case.”

Some of the top players, like Scotland Yard Behavioral Analysist Laura Richards, are introduced toward the end of the trailer. “The victim advocacy side is really crucial and we’re standing her in her shoes 20 years on trying to get to the bottom of this,” she promises.

The team vows to solve the case “once and for all.” Others who make up the team of experts are: forensic investigator Dr. Henry Lee, forensic linguist Jim Fitzgerald, statement analyst Stan Burke, former Boulder police officer James Kolar and forensic scientist Werner Spitz.

One striking point is when the 911 operator who took Patsy's desperate call on Dec. 25, 1996, said no one ever spoke to her. “I think it really would have turned the case around,” she says with tears in her eyes.

“The Case of: JonBenét Ramsey” will air in three two-hour installments in the same week. Don't miss it when it premieres Sunday, Sept. 18, at 8:30 p.m. EDT on CBS. Watch the official trailer here.

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