JonBenet Ramsey's murder still captivates the nation nearly 20 years after the 6-year-old's body was found in her family's basement the day after Christmas in 1996.

WATCH: Father of JonBenét Ramsey Recalls Finding 6-Year-Old’s Lifeless Body In Their Home

"How do you feel about the fact that the police have spent 20 years focused on your family instead of the killer?" Dr. Phil asks JonBenet's father, John.

"Well, it's extremely frustrating," John says. "I've been told by experienced homicide detectives this would not have been a difficult murder to solve had it been done right in the very beginning. We knew in fairly short order that the police were not competent."

WATCH: What DNA Found In JonBenet Ramsey’s Underwear Revealed — But The Public Didn’t Know

Dr. Phil asks, "After JonBenet was murdered in that home, did you ever spend another night there?"

"I never spent another second there," John responds. "I just couldn't do it." Watch the video above to hear more, and watch more from the third installment of Dr. Phil's exclusive interview with Burke Ramsey, JonBenet's brother.