Is Karr Really Guilty?

It all just doesn't add up.

And when ABC News talked to some of the country's leading experts on the psychology of murder, they expressed some doubts about John Mark Karr's confession. Why?

False confessions might be rare, but authorities said they're not uncommon in big cases.

And that's what's caused raised eyebrows within the U.S. criminology community about the latest twist in the JonBenet Ramsey case.

On Wednesday John Mark Karr stopped the presses when he apparently confessed to playing a role in the JonBenet Ramsey murder. The confession seemed to neatly solve a 10-year-old mystery.

But questions are already swirling about what authorities call a possible false confession.

"It takes several forms," said John Damino, professor of criminal justice at Southern Vermont College, and a retired Albany, N.Y., police captain. "A person might be confronted by skillful interrogators and be intimidated into a confession."

But Karr made the statements in public, when not under pressure.

"Or you have a confession, which possibly puts them into better circumstances," said Damino, alluding to the different prison conditions Karr would face in the United States and Thailand.

Possible, but Not Likely

"Another situation, which is equally if not more pathological, is ... some of us cannot separate fact from fantasy," said Arnett Gaston, criminologist and clinical psychologist at the University of Maryland.

"Some people can be so obsessed with a person, a situation, an environment, that they begin to live in the fantasy, but they cannot separate it. It is a kind of psychotic reasoning," Gaston said.

And, according to one expert, that just might be the case with John Mark Karr.

"All of the evidence demonstrated so far reflects erotomanic thinking, in which Mr. Karr is romantically obsessed with JonBenet," said Dr. Michael Welner at the New York University School of Medicine.

"If we follow this along, the history shows Mr. Karr to have developed a passionate obsession with the details of this case that led him to reach out to a professor [Michael Tracey] who put together a documentary that caught Karr's attention," Welner said. "Karr did this at a time when he was very much at loose ends and possibly mentally falling apart.

"He was disconnected from his family, disconnected from his previous identity in the U.S., with no sense of attachment and drifting along, and he connects to someone whom he thinks is important. What may have happened here is a dynamic between Mr. Karr and Mr. Tracey," he said.

Welner, renowned for developing the "depravity scale," which rates the severity of crimes according to public surveys (you can find it at, said he believes Karr may have developed a relationship with Tracey through e-mail and believed he needed a way to keep the journalist's interest.

"I wonder how long Tracey would have maintained contact with Karr if he didn't think there was something to share," Welner said.

"I find it clinically relevant that he would carry on a conversation with someone about JonBenet Ramsey and yet have so little contact with his family that they thought he was dead, and yet there was no history of any bad blood within the family," he said. "As a forensic psychiatrist, when you hear stories of people disengaging from their families and their identity to such a degree that people think they're dead, then you have to ask yourself whether the person along the way started slowly suffering a mental breakdown."

But Welner wouldn't go so far as to say that Karr is not guilty.

"In my opinion, a close evaluation of his person will start to sort some of these questions out," Welner said.