Burke Ramsey is giving his first interview about his late sister, JonBenet Ramsey, in an exclusive sit-down with Dr. Phil, beginning Sept. 12.
Burke was just nine when his 6-year-old child pageant sister was found dead in the basement of their family's Colorado home on Dec. 26, 1996. Nearly 20 years later, Burke, now 29, is revealing what he knows about his sister's still unsolved murder.
WATCH: Barbara Walters Revisits the Questions Surrounding JonBenet Ramsey Case
At the time, parents John and Patsy made the initial call to police, claiming that they found a note demanding ransom for their daughter of $118,000. John later found his daughter's body hours after police completed a search of the home.
JonBenet's death is one of America's most talked-about cold cases. John and Patsy were the primary suspects in the case for more than a decade until police cleared them of any wrongdoing in 2008.
The three-part interview kicks off Dr. Phil's 15th season starting Sept. 12. Parts two and three are set to air Sept. 13 and 19.