One US pedophile had plastic surgery and jumped bail to elude authorities. Another paid thousands of dollars to the family of his victims to gain their silence.
Across Asia, pedophiles have long taken advantage of weak and corrupt law enforcement systems, endemic poverty and networks of like-minded criminals. The announcement that the suspected killer of US child beauty queen JonBenet Ramsey had been arrested in Thailand is a rare victory in a region struggling to address the problem.
The difficulties of catching these criminals was highlighted on Thursday, after police announced the arrest of 41-year-old US national John Mark Karr in Thailand as a suspect in the murder of 6-year-old Ramsey.
According to incomplete accounts pieced together from officials and purported resumes posted on Web sites, 41-year-old US school teacher John Mark Karr traveled the world for years, possibly teaching young children, before he was arrested at a seedy guest house in Bangkok, down the streets from massage parlors and prostitution bars.
US Ambassador John Miller, who heads the State Department's people trafficking office, said part of the challenge of catching pedophiles is that many come across "as upstanding citizens" who have professional careers as doctors, teachers and soldiers.
"This is not easy work," Miller said, noting that the US government has extradited and convicted 29 US nationals for abusing children since 2003, about half of the cases occurring in Asia.
"We've started to make progress, but we haven't made anywhere near enough progress," he said. "We have started to discover the extent of the problem. We have started to get conviction and get message out. But we're just at the beginning."
Hundreds of thousands of girls and boys are believed to be working in the sex trade in Cambodia, Indonesia, Thailand, Vietnam, the Philippines and other countries in an underground industry.
Some of their customers -- mostly older men -- commit their crimes with relative impunity, walking hand-in-and with underage girls in the heart of Bangkok or with boys in a five-story resort hotel on Bali. The riverfront in the Cambodian capital of Phnom Penh also is a favorite spot, where pedophiles buy sex from street children.
"In my country, I never meet super-extra available boys," Italian Alain Filippe Berutti said, after he was convicted in 2002 of having sex with Cambodian youngsters.
Others operate more covertly, finding work as school teachers, music tutors or even volunteers at orphanages where they win the loyalty of youngsters with gifts of candy and toys.
"If they are in a country where there is a lot of poverty and appear to be developing relations with kids and doing things like organizing programs and teaching kids, people want to assume they have benevolent motives," said Janis Wolak, a researcher at the University of New Hampshire's Crimes Against Children Research Center.
"I don't think it's mysterious that these people don't get found out," she said.
Still other pedophiles depend on secretive networks of pedophile rings that have thrived for years in places like Bali or Cambodia.
Often found in cyberspace or through fellow pedophiles, the networks offer sex predators tips on the best places to meet young children or will help arrange sexual rendezvous in luxury condos or on private yachts.