Michael Sandrock, a freelance journalist from Boulder, Colo., told the Rocky Mountain News that Karr, a 41-year-old schoolteacher who has confessed to accidentally killing Ramsey in Boulder in 1996, talked endlessly about the case, citing numerous newspaper stories and details during their chance meeting on the Left Bank.
Sandrock said he met Karr several times in Paris and that each conversation drifted toward the 6-year-old's death.
Sandrock said he beleived Karr "was holding something back. I thought it was because he did a lot of research."
The journalist also said he put him in touch with Michael Tracey, the University of Colorado journalism professor with whom Karr corresponded via e-mail about JonBenet Ramsey's death.
Tracey also made a documentary about the media's coverage of the Ramsey case. Tracey criticizes the media's treatment of John and Patsy Ramsey, the dead girl's parents, who were both suspects for the killing. Sandrock told the newspaper Karr was familiar with the documentary and said the idea that John and Patsy Ramsey were involved brought a "little smile" from Karr.
Sandrock said he tried not to indulge Karr's fascination with the case and did not question how or why Karr claimed to know so many details.
"That would have been the natural thing," Sandrock told the newspaper. "But I just backed off. Let's face it. He's fanatical about it, whether he did it or not. And it's not in my nature (to ask). Being in journalism, you get a lot of obsessed people. It wasn't a topic I had much interest in."
Also, a Northern California woman said she exchanged e-mails and recorded hours of phone conversations with Karr in which he described his fascination with JonBenet's and Polly Klaas's slayings, according to The Press Democrat of Santa Rosa in its online edition Friday.
Klaas was a 12-year-old girl, kidnapped and killed in 1993.
Wendy Hutchens, 49, of Roseville, Calif., told police about her 2001 conversations with Karr weeks before the Sonoma County Sheriff's Office arrested him on five misdemeanor child pornography charges.
Karr remained jailed in Thailand on Saturday. He is due back in the United States on Sunday. A Thai police general said, "The tickets for 41-year-old John Mark Karr's departure are ready."
For most of Friday, speculation swirled around e-mails Karr sent regarding Ramsey's death.
The day before Christmas Eve 2005,sent an e-mail to Tracey. It was one of a disturbing between Tracey and a person investigators believe to be Karr.
A source close to the investigation told CBS News the reason investigators moved in on Karr was because of details in these emails about the Ramsey house that had not been made public, reports CBS News correspondent Kelly Cobiella.
Correspondence obtained by the Rocky Mountain News included one message in which the professor was asked to visit JonBenet's home in Boulder to read aloud an ode called "JonBenet, My Love."
Tracey once worked for CBS News as a consultant on the Ramsey case.
"JonBenet, my love, my life. I love you and shall forever love you. I pray that you can hear my voice calling out to you from my darkness, this darkness that now separates us," read one of the e-mails, which the newspaper said Friday it obtained from a source close to the investigation.
In other e-mails, Karr said he was under federal investigation for "child murder and child molestation" in four states.
"I don't know that he's guilty," said Tracey. "Obviously, I went to the district attorney for a reason, but let him have his day in court and let JonBenet have her day in court and let's see how it plays out."
In another e-mail, the Rocky Mountain News reported, Karr said he sympathized with Michael Jackson, who was accused but later acquitted of molesting young boys.
"I will tell you that I can understand people like Michael Jackson and feel sympathy when he suffers as he has," Karr wrote.
"I can relate very well to children and the way they think and feel," one Karr e-mail said. "I think you are asking if I am much a 'Peter Pan.' In many ways, the answer is yes. In other ways, I suppose it is no, because I am trapped in a world that does not understand."
In another correspondence, Tracey asked whether Karr's "fascination with little girls, which clearly has a strong erotic component, is a way of going back."
"Maybe I am not going back but have simply stayed consistent," Karr responded. "My peer group has not changed since I was a little boy, and girls were the people I was with always. Referring to them as a peer group is somewhat incorrect, but might also be the very definition of what they continue to be in my life."
Despite questions swirling about Karr's role in the death of JonBenet Ramsey, the slain 6-year-old's aunt said Friday her family is.
"We are optimistic, but it's wait-and-see," said Pamela Paugh, sister of JonBenet's mother Patsy Ramsey, outside her family's Roswell, Ga. home. "We've been patient for nine and a half years; what's a few more months?"
Paugh, who has acted as her family's spokeswoman since the arrest, said the family has its own concerns about Karr's statements but remains confident in the work of Boulder County District Attorney Mary Lacy and other investigators.
"She would never do something (haphazardly) when she knows the world's eyes are on her," Paugh said of Lacy. "She's not going to just go out there willy-nilly and pick up some nut case."
CBS News legal analyst Andrew Cohen, who has followed the Ramsey case extensively, agrees.
"If they don't have anything, they become laughingstocks of all time in the law enforcement profession, and I'm simply unwilling to believe that," Cohen says of the Boulder DA's office.