SNEAK PEEK: Who Killed JonBenét?

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This year marks 20 years since six-year-old JonBenét Ramsey was found dead in the basement of her family's home in Boulder, Colorado. In a Two-Hour Dateline Special, first-ever TV interviews with former Boulder PD Detective Jane Harmer, former Denver PD Detective Tom Haney and never-before-seen case documents. Josh Mankiewicz reports Friday, September 9 at 9/8c.