This is a partial transcript from "The O'Reilly Factor," August 25, 2006, that has been edited for clarity.

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BILL O'REILLY, HOST: In the "Unresolved Problem" segment tonight, much is being made about DNA evidence in the JonBenet Ramsey murder case, as you just saw. The thinking goes if John Mark Karr is a DNA match, Boulder's got a case against him. But if he isn't a match, this couldn't be the guy. But is it true?

With us now is criminologist Dr. Casey Jordan. So doctor, slam dunk one way or the other?

CASEY JORDAN, PH.D., CRIMINOLOGIST: Yes, I believe so, because of the bizarre behavior of this particular suspect, I think that the public is really going demand a DNA match, a really strong conclusive piece of forensic evidence. Not just his own statements to determine that this is the guy.

KASICH: Now, you know, Karr has said -- now this is really bizarre. I'm sure [you might share that sentiment, too] being a criminologist. He said "Oh, you can't pay attention to the DNA." What is that about, in your opinion?

JORDAN: Well, it's almost what we would call a double thinker or triple think. It's a contra- indicator. If he anticipates that there's not going to be a match, and he says so before the results come in, then he's already got an explanation built up in his head as to why it may not match. And of course, he says the science isn't perfect. But in fact, it could just be he just wasn't there.

KASICH: Yes. Now how much DNA do you need in order to have an effective amount where you can prove things? Somebody is saying that there may not be enough DNA.

JORDAN: Right. Well.

KASICH: How much do you need? And what do you get if you don't have enough?

JORDAN: Miniscule amounts. Something like the head of a pin is just fine. But the problem is it's the quality of the sample. Small isn't so much the issue as pure DNA. And when its mixed or contaminated with other DNA through human error, through the handlers, through people at the crime scene...

KASICH: How about with another person's blood? They're saying, you know, that there's this little bit of DNA is mixed in with her blood.

JORDAN: With her blood. And it could be from saliva, from dandruff, from sweat. It could it be from the manufacturers at the plant that made those underwear that she was wearing. It could it be from the blanket that was over the body when her father brought her upstairs and laid her on the carpet. It could it have been from anything.

KASICH: Well, you know, this thing about the underwear from the factory showed traces of DNA in other samples, or blood, I guess it was, right?

JORDAN: Right.

KASICH: I mean, did you ever hear anything like that? I mean, how does somebody's DNA, a factory worker contaminate this kind of evidence? Is that common?

JORDAN: It's more common than you would think because the whole concept of transference is that every day, as we touch door knobs, as we stand on the subway and touch a pole, if somebody sneezes or coughs on us, we have their DNA on us. Even when I shake your hand, I could put my DNA on you.

So we're just, as the science gets more and more precise, we're beginning to realize how much transference happens. And if a factory worker sneezed on the underwear while putting them in a plastic package, you could still get that DNA.

KASICH: Well, then, aren't you really taking us to the place where we won't -- that DNA is not a slam dunk? Isn't everything you're saying lead up to the fact that DNA may not prove conclusively one way or the other, either because the DNA is also from a factory worker, there's not enough there, it's mixed in with blood. I mean, is it possible that at the end of all this we're going to say that's not the clue here?

JORDAN: Well, you have a gray spectrum, areas of gray in which you have probabilities of matching that are more highly consistent and then beyond the pale definite, definite slam dunks.

And that's going to be left to the jury to determine whether or not what the scientists say in terms of a DNA result is enough to convince them that John Mark Karr was there.

KASICH: All right, you being a criminologist study the minds of these people. But you know a lot of people want to know. How does a guy who doesn't have this kind of history -- I mean, clearly, he's a bad guy from the child porn [charges] he's a bad guy. How does a guy like that, though, you know, pull something like this off, presuming it's him? We don't know that it's him, but how do they get into the house? How do they not create a crime scene that points the evidence at him? What can you tell us about this?

JORDAN: Well, I think that most people in the criminology community today don't believe that his behavior and his profile as a pedophile is consistent with this crime scene.

He — you would have to be an extraordinarily, highly organized killer to — who planned it thoroughly to not leave any DNA at the scene.

And nothing in his background, which is of course a very disturbed childhood, no doubt that he's a fixated preferential pedophile. But those types of pedophiles are rarely killers who bash in the skull of a six-year old girl. This just isn't consistent with what we know about a man like him.

And don't forget he says he loves, present tense, JonBenet.

KASICH: You know, is this ever going to end? If it's not John Mark Karr, do you think that's it? I mean, this case just goes away. I mean, people are worn out. Everybody is worn out from this.

JORDAN: Yes.

KASICH: What's your feeling about that? Can this case carry on and they ultimately find the person in your opinion?

JORDAN: I think that if he is ruled out, and the public would like to it be him, believe me.

KASICH: Yes.

JORDAN: But without DNA, if he truly is excluded, and assuming the D.A. doesn't go forward with the prosecution, I think that that will actually renew the energy of both the public and the D.A. to truly determine who is the killer of Jonbenet Ramsey.

KASICH: Unbelievable story, huh?

JORDAN: And it continues.

KASICH: Totally unbelievable and horrible.

All right, thank you Dr. Jordan.

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