BANGKOK, Thailand - With the help of a computer program, German police digitally unscrambled the swirls that obscured the face of a man depicted having sex with boys in Vietnam and Cambodia.
With the reach of the Internet, an unprecedented worldwide appeal by Interpol brought hundreds of responses via e-mail to the French-based police agency.
And with the aid of traced cell phone calls, Thai police tracked the suspect to a house well off the usual tourist trail, in northeastern Thailand.
The high-tech police work resulted in the arrest Friday of Canadian schoolteacher Christopher Paul Neil, suspected of sexually abusing Asian boys, after a three-year global manhunt.
Neil, 32, was detained at a house that he had rented with a Thai transvestite friend in the rural province of Nakhon Ratchasima.
'I think he knew we were coming,' said police Col. Paisal Luesomboon, who was on the five-member police team that made the arrest. 'He knew that there was an arrest warrant issued and that his face was posted everywhere.'
He said Neil acknowledged being the man they were seeking, but didn't comment on whether he was the person depicted in about 200 Internet photos having sex with a dozen different boys between the ages of 6 and 12.
Only 10 days earlier, Interpol had issued the appeal to identify the man whose face had been digitally obscured by swirling part of the original photos.
After German police computer experts were able to reverse the process, making the face recognizable, some photos of the man were publicly circulated, and hundreds of people responded with tips on his identity, leading to Neil's arrest.
'Let all international criminals and fugitives be put on notice that Interpol, its police partners in 186 member countries, the public and the Internet present new and powerful possibilities for hunting them down wherever they might try to hide,' Interpol Secretary General Ronald K. Noble said in a statement.
Taken to the Thai capital Bangkok, Neil - in handcuffs and with a blue shirt draped over his head - was led into national police headquarters. He made no comments to waiting reporters.
He remained silent and unsmiling when he was presented to journalists at a news conference, where the shirt was removed from his head but his eyes remained hidden behind a pair of sunglasses.
'He wants to exercise his rights not to speak until he gets legal advice,' said Maj. Gen. Wongkot Maneerin, deputy national police chief.
Neil was charged Friday with detention of a child under 15 without parental consent, punishable by up to three years in prison; taking a child under 15 from his parents without consent, punishable by five to 20 years; and sexual abuse of a child under 15, punishable by up to 10 years.
He is supposed to be brought before a judge today in order for police to keep him in custody pending further investigation.