As investigators puzzle the life and mind of, confessor to the killing of JonBenet Ramsey, they must unravel an elaborate and hazy narrative woven in part by Karr himself, much of it constructed around a clear and chilling theme — a yearning to be close to children.
That desire, in retrospect, appears as heartfelt as it does disturbing.
In an interview for an English-teaching job at one of Bangkok's elite Thai schools, Karr left a good first impression. He was clean-cut, articulate and had a resume detailing experience in schools in the U.S., Japan and elsewhere.
But after just two weeks on the job, Karr was asked to leave.
"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," Banchong Chompowong, assistant director of Bangkok Christian College's English immersion program, told The Associated Press on Friday.
Karr is a man who, while wanted as a fugitive on child pornography charges, sought to impress prospective employers with a long record of accomplishment preparing young lives "for a successful future."
Karr went through his teen years mostly unnoticed, one of his classmates told CBS News 48 Hours correspondent Erin Moriarty, keeping mostly to himself.
He is a man who twice married teenagers — one just 13 at the time. Both would later claim they had been coerced.
And he is the man who years ago confided to family members that he was deeply troubled by the murder of the Colorado 6-year-old, who told U.S. investigators that he picked JonBenet up at school, drugged and had sex with her beforein the U.S. state of Colorado in 1996, Thai police Lt. Gen. Suwat Tumrongsiskul told The Associated Press.
But questions have been raised about some of his claims, including whether he drugged the 6-year-old, sexually assaulted her or was even in Colorado at the time of the slaying.
On Friday, Suwat contended that he had been misinterpreted, saying that drugs may not have been used and that Karr didn't mention picking her up at the school. But he did confirm Karr saying he had sex with her.
Suwat said that he was quoting a documentary which said someone had gone to pick up the child at the school before she disappeared and was found dead.
Asked Friday if Karr plied the girl with 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.
Among the possible discrepancies between his confession and earlier established facts were these: an autopsy was inconclusive about sexual assault and few experts believe that a girl who was slowly strangled with a garrote was killed by accident. There are even questions whether Karr was in Colorado at the time of the slaying.
In Franklin County, Ala., school officials told the New York Times that records showed Karr had been at work there until the end of the term on Dec. 19, 1996, a week before the murder.
Lara Karr said she was with her former husband in Alabama at the time of JonBenet's killing and she does not believe he was involved in the homicide. Attorney Michael Raines said he has instructed Karr's ex-wife to go through photographs of the family back in 1996 at Christmas time, when she claims they spent the holiday together.
"I do feel that, based on the fact that warrants have been issued, that (the district attorney) obviously has a sufficient amount of evidence," Ollie Gray, a private investigator, told CBS News' The Early Show.
Moriarty reported that investigators may have arrested Karr this week not because they had definitive evidence linking him to the Ramsey murder, but because they feared he might hurt a child in Thailand.
A former Boulder district attorney who investigated the Ramsey case told Moriarty he has serious doubts about any confession because of the amount of public information surrounding the case. "I am very concerned about the viability of this case today, it does not sound to me like they've done their homework sufficiently to have arrested him at this time," says Trip DeMuth.
It's difficult to know how much to believe of the life Karr says he has led since JonBenet was found strangled and beaten a decade ago in the basement of her family's home.
But in his own words, it all seems quite real.
"I awoke the children in the morning and gave them breakfast," Karr wrote in one online resume, recounting life as a private teacher and caregiver of three girls in Germany, aged 7, 11 and 12. "At day's end, I made sure the children had their evening bath, then put them to bed and read to them before they went to sleep."
Karr, who arrived in Thailand earlier this year looking for work as a teacher, claims to have spent years skipping from job to job, country to country, nearly all the time working with children. Karr taught for two months in early 2002 at I&S Language School in Seoul, South Korea, said Kim Sun-tae, an official at the Seoul Dongbu District Office of Education. And in Taiwan, the National Police Administration said Friday that Karr entered the country in August 2005 and left two months later.
School officials in Alabama and California confirmed that he worked in both states as a substitute teacher in the latter half of the 1990s and in 2001.
"He just seemed like somebody who thought he wanted to be a teacher," said Bob Raines, superintendent and principal at Wilson Elementary School, in one of the four districts near Petaluma, Calif. where Karr worked. "After a few days, I could tell it just wasn't for him."
One of Karr's former wives, Lara Karr, told KGO-TV in California that her ex-husband spent a lot of time studying the cases of Ramsey and Polly Klaas, who was abducted from her Petaluma, Calif., home and slain in 1993.
It is not easy to establish Karr's whereabouts at any point in recent years.
As an adult, Karr wrote in one online resume that he worked for years in real estate and restored old homes. His work in schools appears to have begun in 1996 — the year of the Ramsey murder. According to the resume, that was the start of a five-year stint teaching in "some of the most prestigious schools in the United States, working with children from high profile families."
But that is not the way people and court paperwork in Marion County recall it.
In 1984, when Karr was 19, he married a local girl, Quientana Shotts, who was 13 at the time, county court records show. Shotts filed for an annulment the following year, complaining that she was "fearful for her life and safety." In a response filed with the court, Karr contested Shotts' age, saying she was in fact 14.