The murder of child beauty queen JonBenet Ramsey remains one of the most mysterious cold cases in America nearly 20 years since the morning the 6-year-old beauty queen was found lifeless in her family's Boulder, CO basement. JonBenet's brother Burke, who was 9 at the time of the murder, broke his silence in an interview with Dr. Phil, and today, he shares his theory about who committed the crime.  
"I kind of always thought it was a pedophile who saw her in one of the pageants and snuck in," he tells Dr. Phil in an interview airing today. "Probably some pedophile in the pageant audience."
Dr. Phil asks, "Did you witness anything that night that over the last 20 years you have kept a secret?"
"I don't know anything more than what everyone else already knows," affirms Burke.

WATCH: What A Family Photo Drawn By 9-Year-Old Burke Ramsey Looked Like After JonBenet’s Murder

Burke recalls giving DNA evidence to investigators, as did his parents. Watch the video above to see what police knew about the DNA found in JonBenet's underwear that wasn’t revealed for months.

Watch more from this show here.