BANGKOK, Thailand (CNN) -- John Mark Karr, the notorious suspect in the 1996 death of 6-year-old JonBenet Ramsey, is set to leave his Thai jail cell and fly to Los Angeles on Sunday, a Thai Airways official said.
Thailand's head of immigration, Lt. Gen. Suwat Tumrongsiskul, did not say how many U.S. officials would accompany him during the flight, which is scheduled to arrive Sunday evening.
Thai officials said that Karr has two English-speaking Thai guards monitoring him at all times, but said the round-the-clock presence is not a suicide watch.
Homeland Security official Ann Hurst, who visited Karr at the Immigration Detention Center, said upon departing that he was in "good" condition.
Karr is being deported rather than extradited, which allows U.S. authorities to sidestep usually lengthy extradition proceedings. He is named in a Boulder, Colorado, arrest warrant on suspicion of first-degree murder, kidnapping and child sexual assault.
The investigation on Friday was focusing on Karr's writings, including a 1982 high-school yearbook inscription he made for a friend.
Karr on Thursday said he was involved in the death of the child beauty pageant winner, whose body was found December 26, 1996, in the basement of the Ramsey family home in Boulder. However, questions have since been raised about some of his statements.
The yearbook entry ends with Karr saying in capital block letters, "Though, deep in the future, maybe I shall be the conquerer [sic] and live in multiple peace." (Watch details emerge of Karr's background -- 3:30)
A ransom note found in the Ramsey home had demanded money for JonBenet's return and had ended with the word "Victory!" and was signed "S.B.T.C." Authorities want to know whether those letters might stand for "shall be the conquerer" and whether they could have been written by the same person.
John Hargett, who once ran the documents section of the U.S. Secret Service, told CNN the letters represent "a very interesting coincidence." But he said he saw no similarity between the handwriting used in the ransom note and that in the yearbook. (Watch how he analyzes the handwriting -- 2:00 )
Murder scene secrets
Under questioning by U.S. authorities in Bangkok, Karr has provided gruesome details about the condition of Ramsey's body -- information that had been kept secret for nearly a decade, a U.S. law enforcement source told CNN on Friday. (Watch what this revelation means for the investigation -- 2:17)
The details were known only to the medical examiner and investigators looking into JonBenet's slaying, the law enforcement official said. (Read about the crime scene)
Despite his remarks, Karr's ex-wife and family members insist he was not involved in Ramsey's death.
Some observers have speculated that the 41-year-old may have falsely confessed -- either intentionally out of a desire to link himself to such a high-profile case or because he is delusional. (Watch theories surrounding why Karr confessed -- 2:13)
Prison official: No tie to Polly Klaas
Meanwhile, a search of personal effects of Richard Allen Davis yielded no evidence that Karr was in contact with the convicted child killer, said Vernon Crittendon, a spokesman at California's San Quentin prison.
"We now are convinced that we have no evidence that shows that there's any correspondence taking place between Richard Allen Davis and John Karr," Crittendon said.
Davis was convicted in the 1993 killing of 12-year-old Polly Klaas, who lived in Petaluma, California, where Karr also lived with his wife in 2000 and 2001. Karr was fascinated by both the Klaas case and the Ramsey killing, according to Karr's ex-wife Lara. Karr was arrested in Petaluma on charges of possessing child pornography.
Did Karr contact the Ramseys?
In late May, investigators from the Boulder district attorney's office approached JonBenet's parents, John and Patsy Ramsey, with information that one or more e-mails had been intercepted expressing a desire to meet with them, according to their family attorney Lin Wood.
Authorities said they were tracking an individual but did not mention his name, Wood said. Wood said he believed the e-mailer was Karr.
The Ramseys had told investigators they were willing to meet with the unnamed person, if doing so would assist the investigation -- but the meeting never took place, Wood said. Patsy Ramsey died of ovarian cancer in June.
Karr has said he did contact Patsy Ramsey, The Associated Press reported. (Watch Karr describe contacting the Ramseys -- :44)
The Rocky Mountain News published excerpts on its Web site Friday of what investigators say they believe are e-mails between Karr and Michael Tracey, a journalism professor at the University of Colorado in Boulder. (Read paper's account of toy bear e-mail)
One read: "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. ..."