A Thai Airways jet carrying John Mark Karr, 41, landed at Los Angeles International Airport at about 9:30 pm Sunday (0430 GMT Monday).

 Witnesses said the suspect made the 15-hour trip in style, drinking champagne and feasting on fried shrimp in the company of three security escorts.

 "It was a little weird to travel with someone like Mr. Karr," Dan Shieff, a banker who happened to be on the same flight, told reporters. "He was smiling, relaxed and very, very chilled out."

 After landing, Karr was whisked out of the plane by US Customs officials and helicoptered to a local jail, where he was expected to spend a couple of days as issues related to his extradition to Colorado were being resolved.

 Michael Lopez, a spokesman for the Los Angeles Police Department, told AFP that Karr "will be separated from other inmates and checked on every 15 minutes."

 The suspect will face US investigators trying to solve the murder of six-year old Ramsey, in a lurid case that captured the nation's attention for years.

 Thai police have said he had confessed to killing Ramsey unintentionally. They said Karr told them that he was "in love" with the little blonde girl, who wore makeup and glamorous outfits and struck adult poses in her appearances at child beauty pageants.

 However, Karr told reporters in Bangkok on Thursday, a day after his arrest, that he did not kill her and that her death "was an accident."

 Karr was tracked down in Bangkok after authorities studied four years of e-mails between him and University of Colorado journalism professor Michael Tracey, who has closely followed the Ramsey case.

 According to excerpts of some of the e-mails published in the Rocky Mountain News, the two discussed Karr's sexuality conflicts.

 "I am trapped in a world that does not understand," Karr said in one exchange. "I can understand people like Michael Jackson and feel sympathy when he suffers as he has."

 While his arrest has revived huge interest in the murder -- in which, at one point, JonBenet Ramsey's parents were investigated as possible suspects -- suspicions arose that Karr might not be the girl's killer.

 Earlier this week, Karr's former wife, Lara Marie Knutson, told a San Francisco television station off-camera that on the day Ramsey's strangled body was found, she was with her then-husband and their three sons in the southeastern state of Alabama.

 Her lawyer also said that she recalls that they were spending the Christmas holiday together when the murder took place on December 26 -- the day after Christmas -- in the western state of Colorado.

 Knutson's 11-year marriage to Karr ended in 2001, the year Karr was charged with possession of child pornography in Sonoma County, California, north of San Francisco.

 A report in The Denver Post newspaper Sunday suggested Boulder District Attorney Mary Lacy left large gaps in her investigative work as she tried to build a case against Karr before his arrest.

 It was only Wednesday, when Karr was already in Thai custody, that the prosecutor's office called the Marion County School District in Alabama to seek a sample of Karr's handwriting to compare it with the ransom note allegedly left by Ramsey's killer, the paper said.

 Experts believe the handwritings do not match.

 Lacy's office has still not contacted the Colorado Bureau of Investigation to compare Karr's handwriting, a palm print, footprint or even shoe size to the evidence found at the murder scene, The Post said.

 Nor has the prosecutor contacted Karr's ex-wife and children to see if they would provide an alibi for Karr's whereabouts at the time of Ramsey's murder, according to the report.

 Karr's departure followed a report he had sought surgery at a sex-change clinic in central Bangkok.

Agence France Presse