It’s been 20 years since child beauty queen JonBenét Ramsey was found dead in the basement of her Colorado home on December 26, 1996 – a murder that remains unsolved.

Suspicion initially fell on her parents John and Patsy, but they have always proclaimed their innocence.

Now, her older brother Burke speaks out for the first time in an exclusive interview with Dr. Phil starting Monday, September 12. The 29-year-old shares never-before-heard details about his sister’s mysterious death, and, hidden for years, secret interrogation interviews conducted with Burke at ages 9 and 12 will be revealed.

“I remember my mom searching my room that night saying, ‘Where’s my baby? Where’s my baby?’” Burke tells Dr. Phil in his first-ever media interview.

In this ripped-from-the-headlines exclusive interview, Dr. Phil asks Burke, “Has it ever occurred to you that your parents actually thought you did this and didn’t ask you because they didn’t want to know?”

Check here to see where you can watch the interview 20 years in the making on the season premiere of Dr. Phil.

MORE: Exclusive Interview With JonBenét Ramsey’s Brother: Secret Interrogation Tapes Revealed