Transcript for JonBenet Ramsey's parents are interrogated, DNA evidence is made public: Part 7
Thank you to all involved in our clinical trials. Within a few weeks of jonbenet's murder, police had an important clue, the discovery of foreign DNA on her body. Crime scene detectives discovered DNA underneath jonbenet's fingernails and in her underwear that did not match anybody in the Ramsey family. That was not something that was made public for quite a long time. They knew at the time that there was DNA in her panties and that it was mixed foreign DNA and it was not the Ramseys' DNA. Not Patsy's. Not John's. And not Burke's. Detective Lou smit was like, whoa, while you're pouring water all over the intruder theory, you're not revealing that you have found unidentified DNA, and it doesn't match anybody in the Ramsey family. Lou is just incensed that the focus is still being, well, it could be Patsy. Maybe we need to get her to confess. The Ramseys had been interrogated by police four months after jonbenet's death. But now authorities want the Ramseys to come in again for a formal, videotaped intear interrogation. There were months and months of negotiations. Things about whether they could be videotaped. What are the questions going to be? Should the Boulder police be a part of it? Because the Ramseys said, we don't trust the police. We don't want them there. Ultimately, the interrogation took place at a different police department. And at the end, the Boulder police had to watch it from another building. The Ramseys finally sit down with the police for a videotaped interrogation in June 1998, a year and a half after jonbenet's murder. Today's Wednesday, June 24, 1998. Broomfield police department. Patricia Ramsey. Tom Haney, who is one of the most respected homicide detectives out of Denver, was chosen to interview Patsy Ramsey. Patsy Ramsey had a year and a half to prepare. I knew that it was going to be tough to get a spontaneous Do you ever recall purchasing black duct tape like this? No. It seems like there can't be a house in the world that doesn't have duct tape, because it repairs everything. Well, I never liked it because it's so gooey. Isn't it gooey? He started off softly and kindly and curious, and then he got pointed with his questions, and that made Patsy angry. If I told you right now that we have in the process of being examined trace evidence that appears to link you to the death of jonbenet, what would you tell me? That is totally impossible. Go retest. How is it impossible? I did not kill my child. I didn't have a thing to do with it. She said it was impossible that we had physical evidence linking her to the crime. I'm talking about scientific evidence. I don't give a flying flip how scientific it is. Go back to the damn drawing board. I didn't do it. John Ramsey didn't do it, and we didn't have a clue of anybody who did do it. I am so taken with her swagger. She just tells them, you know, you think you have some evidence on me? Well, you better look again. We loved that child, okay? We're not involved. Read my lips. Let's find out who is. She's very feisty. She's very combative. And that doesn't mean she's guilty, but it doesn't mean she's innocent, either. My life has been hell from that day forward. And I can't stand the thought thinking somebody's out here walking on the street. God knows they might do it again to some other child. You know, quit screwing around, asking me about things that are ridiculous, and let's find the person that did this. Lou smit was assigned to interrogate John Ramsey. When Lou interviewed someone, he pried anything out of people just by being understanding and really listening. Now, John, and I know this is -- we're touching right back on a very delicate spot. But was this tape wrapped around anywhere, or was it stuck down? It was very firm across her lips. I thought John was much more measured and composed. You don't see the drama. I see a lot of pain in that man. I reached up, flipped the latch, opened the door. I knew immediately what I found. Okay, and you say immediately. There was a white blanket, um, and I just knew I'd found her. I think those tapes were so intriguing to watch. But the bottom line is, there's nothing there that they could use to say, a-ha, we've got you. Both John and Patsy deny in the interrogations that anyone in their family killed jonbenet. And we want to do anything we can to help solve this case for you. My dad's conclusions after that interview were just firmed up his belief that the Ramseys had nothing to do with this murder. I'm not saying parents don't kill the kids. Parents do kill their children. But they're trying to say Patsy did it. Their actions before, during and after are all consistent with innocent people. They didn't do it. My dad started getting frustrated as time went on because he felt that the case against the Ramseys was being slanted where no other evidence was coming in. I thought there was something drastically wrong and that there was a gross injustice in this case. I had seen evidence of an intruder in the house that night. Lou smit thought the Ramseys were being targeted unfairly. And he didn't believe that police were listening to him. Smit so strongly disagrees with the prosecutor's focus on the Ramseys that he is resigning from the case, saying, the case tells me John and Patsy Ramsey did not kill their daughter. He wrote a letter to Alex hunter, telling him that he couldn't be a part of the persecution of these people, is how he termed it. He wrote, I intend to stand with this family and somehow help them through this and find the killer of their daughter. My dad may have resigned from the district attorney's office, but he never stopped work on the case. He walked in jonbenet's shoes, and he owed it to her, he felt, to continue his investigation. One thing Lou smit fought to do was tell a grand jury his side of the story, the intruder theory. There were too many questions. In particular, that DNA in the underwear that appears to have been from a man didn't match anyone at all.
This transcript has been automatically generated and may not be 100% accurate.