BANGKOK, Thailand (AP) — Suspect John Mark Karr on Friday awaited extradition to the United States, where questions mounted over whether his stunning confession related to the slaying of 6-year-old JonBenet Ramsey was that of a killer or merely someone obsessed with the case.

Hours after John Mark Karr told reporters in Thailand he was with JonBenet when she died, questions arose about his claims – including whether he sexually assaulted the young American beauty queen or was even in Colorado at the time of the killing.

Lt. Gen. Suwat Tumrongsiskul of the Thai immigration police changed some details Friday of the account he had given of what Karr told investigators. In a telephone interview Thursday with The Associated Press, Suwat quoted Karr as saying he had sexually assaulted the girl and given her drugs. He also told reporters before a news conference Thursday that Karr had claimed to have picked up JonBenet at her school.

On Friday, Suwat confirmed to the AP his account of the sexual assault. But asked Friday if Karr gave the girl drugs, Suwat said the suspect described the encounter with JonBenet Ramsey as “a blur.”

“It may have been drugs, or it may have been something else because (Karr said) it was a blur, blur,” Suwat said.

Suwat also said Friday his statement about the girl being picked up from school was based on a documentary he had seen and not the interrogation.

Meanwhile, slices of Karr’s globe-trotting life as a teacher began to emerge as he remained detained in an immigration jail in Thailand’s capital.

An administrator at an elite Bangkok school described Karr as articulate and polite, but too strict, and said he was fired after two weeks on the job.

“John Karr came to us with a good resume and with credentials, but then we allowed him a trial (period) with students, we found he was too strict,” said Banchong Chompowong, an administrator at Bangkok Christian College’s elementary school.

Experts said the questions surrounding Karr’s story put more pressure on corroborating evidence such as DNA.

“They either have a miss or a match on the DNA,” former Denver prosecutor Craig Silverman said. “If it’s a miss, the prosecution has serious problems. If it’s a match, then it’s game, set and match for this case. Couple the DNA with the kooky confession and it’s enough for most people to convict.”

“The bottom line is that they now have a confession and until and unless they can corroborate that confession with either physical evidence or strong circumstantial evidence, that’s all they have,” said Scott Robinson, a Denver attorney who has followed the case from the beginning.

“I am so very sorry for what happened to JonBenet,” Karr told The Associated Press on Thursday as police brought him through his guesthouse to collect belongings following his arrest. “It’s very important for me that everyone knows that I love her very much, that her death was unintentional, that it was an accident.”

Suwat, the Thai police general, said a Thai officer asked Karr why he had sex with a 6-year-old girl.

“He said that at the time it was just a blur. He said they were lovers,” Suwat told The Associated Press.

Suwat said Karr, whom he described as “quiet and kind of strange,” now wanted to go back to the United States to fight the case.

He said U.S. authorities were preparing documents and plane tickets for the return journey. The departure could take place at any time, he said.

The divorced father of three children, once detained on charges of possessing child pornography, apparently traveled the world searching for teaching jobs. Suwat said the suspect had visited several Asian countries in recent years, but provided no details.

In Taiwan, the National Police Administration said Friday that Karr entered the country in August 2005 and left two months later. The NPA didn’t know whether Karr taught during his stay and had no indication he engaged in any criminal behavior.

Karr was arrested a day after he began teaching second grade in Bangkok, District Attorney Mary Lacy told reporters in the Colorado.

In June, he taught first graders at Bangkok Christian College, Thailand’s oldest private school, established by American Presbyterian missionaries in 1852. The school caters to about 5,500 male students in 12 grades and is regarded as one of Bangkok’s top private schools.

“He was qualified to be a teacher. He had a diploma and has experience in teaching in Bangkok for some time,” said Banchong, assistant director of the school’s English immersion program.

He was very presentable, Banchong said. But he was dismissed after two weeks when parents complained that he was too strict with their children, he said.

Banchong said that Karr also had taught at St. Joseph’s Convent, another prestigious elementary and secondary Thai school. But officials there refused to talk to reporters.

Karr will be taken within the week to Colorado, where he will face charges of first-degree murder, kidnapping and child sexual assault, U.S. officials in Bangkok have said.

Denver attorney Larry Pozner, past president of the National Association of Criminal Defense Lawyers, said there were “serious questions” about the case.

“I hope we have found the murderer of JonBenet, but I have not heard the evidence that compels that conclusion,” he said.