Eric Toth was on the FBI's 10 Most Wanted list and had been featured on America's Most Wanted, but last year he may have been set to take to the stage.
He appeared to be booked to speak at a Las Vegas tech conference.
Colleagues knew the speaker under a different name: as an Austin, Texas-based tech writer and computer technician they described as brilliant and friendly. But they now suspect that he is the same man who is accused of filming a sex act with a child while he was a teacher at the District of Columbia's exclusive Beauvoir school in 2007 or 2008.
They realised the night before the October speech that the tech writer had vanished. Calls and emails went unreturned. His Facebook page went dormant. They never saw him again.
His whereabouts remained a mystery until Toth, 31, was arrested in Nicaragua in April.
Three people who saw arrest photos of the lanky man with long brown hair said he was the same person they knew from Austin. FBI officials declined to confirm their account. Toth's attorney did not return a call for comment.
"My reaction was shock," said Joel Stewart, one of the man's former bosses at a computer repair store.
"This was not an unlikable person. I think a lot of us came to think of him as something of a friend."
During Toth's five years on the run, the pattern played out again and again as the man the FBI said was an expert in social engineering and computers was able to invent fresh personas, allegedly obtain fraudulent documents and win the trust of unsuspecting people.
When it appeared that he might be discovered, he would simply melt away.
All the while, the man, who authorities warned would not stop molesting children until he was caught, had contact with kids.
The Washington Post has been able to reconstruct his time in hiding from the District to the Southwest to Latin America.
"It's a case study in you never know who you are standing next to," said Chris Bangs, who worked with the tech writer.
The small Beauvoir school educates the children of some of the most powerful people in the nation's capital.
US senators, White House staffers and World Bank employees have sent their children there.
Parents said Toth stood out among the school's highly regarded educators. The third-grade teacher was adept at relating to his students and making them feel smart. When they needed help, he would sometimes tutor them for free. He babysat others.
But along with the dedication, Toth had quirks: He slept nights in his classroom closet and dried socks on the school's windowsills. He also spent nights at some children's homes.
Toth's reputation imploded at the end of the 2008 school year. A Beauvoir employee discovered images on a camera assigned to him that a federal prosecutor would later say were "any parent's nightmare".
An arrest warrant on possession of child pornography was issued for him in federal court in the District. He was later indicted in Maryland in the production of child pornography.
Charging documents said he produced a video of himself touching a child at a Maryland home in 2007 or 2008. The child was younger than 14.
Beauvoir's principal immediately confronted Toth and had him escorted off campus before calling police that afternoon. The small head start was all Toth needed.
By the next day, he had made it to the Midwest. In the coming days, he visited his parents in Indiana and then drove to a long-term parking lot at the Minneapolis-St. Paul airport.
When authorities found his Honda a month later, they discovered images of child pornography, possibly taken when Toth worked as a counsellor at an all boys summer camp in Wisconsin from 2004 to 2006.
There was also a suicide note saying Toth's body could be found in a nearby lake. Authorities searched but found nothing. They concluded that Toth had faked his death.
His trail was cold. It was his first disappearing act.
David Bussone told people that he was turning his back on a world of privilege when he arrived at a Phoenix homeless shelter and resource centre in 2009. He said he was once an educator at an elite East Coast school but wanted to re-dedicate his life to the downtrodden.
"He gave us the impression that he was disgusted with the wealth he was working with," said Jessica Berg, executive director of the Lodestar Day Resource Center.
"He wanted to do something differently."
Bussone told people that he had taken a five-year vow of poverty. He would live like many of the people he served - in the shelter. The FBI thinks Bussone was Toth's alias.
Berg described Bussone as quiet and respectful. He went about his mission to serve and soon became a trusted volunteer.
Bussone was particularly adept at calming clients who were upset, Berg said. He volunteered on 12-step programme retreats for the homeless.
As Berg was being interviewed by phone on a recent day, she remembered that she had kept an unopened letter addressed to Bussone and flipped through papers until she found it.
She opened the envelope to find a book from a Catholic organisation about devoting yourself to prayer for redemption. Berg thought for a moment and then offered her take on Toth.
"I do feel like he wanted to figure out how to redeem himself in some way," Berg said.
"Maybe his five-year vow of poverty and his work here" were "a way of doing it".
If so, it was work that was left undone.
Starting in 2009, America's Most Wanted aired segments on Toth. His image flashed on television sets across the country.
Berg said one of Lodestar's clients saw the piece.
Her recollection was fuzzy, but she said either the client confronted Bussone, saying he looked like Toth, or word got back to Bussone that a client had started asking questions about whether he was the fugitive. Either way, Berg said, Bussone disappeared the next day.
Gracie Braun met the man who would become the Austin tech writer at the Rainbow Gathering in New Mexico in July 2009.
The colourful events at the gathering are a vestige of '60s counterculture, aimed at creating an alternative to capitalism and consumerism for a few days.
Items are bartered. Meals are shared. Braun recalls meeting the man in a communal kitchen.
He was well-spoken, intelligent and observant. Braun said she appreciated his helpfulness.
When the gathering ended, she offered him a ride.
"He had an open agenda." Braun said.
"He said he would go where life or the universe would take him. I told him I was going to Austin. He said: Austin is where I'm going then. I'm glad to have a ride."
Back home, Braun helped him get a job at a computer repair store where she worked called PC Guru.
Paul Mullen, the owner at the time, said he had no reason to suspect the man, because his driver's license and Social Security number checked out.
Toth allegedly used bogus papers and stole identities during his time as a fugitive.
Mullen said the man was a whiz with computers, repairing machines in half the time it took other people. But he had one habit that annoyed his bosses.
"If people didn't have enough money, he would just fix their computers without charging," Mullen said.
"Money did not concern him at all."
Mullen said the man settled into life in Austin, working at the store for two and a half years.
When it changed hands, he took on an even larger role, planning business strategy and handling customers.
"He is really savvy about how people work," said Stewart, the new owner of the store.
But, given the accusations in the Toth case, there were also troubling signs.
The man told Mullen that he was tutoring two children and giving financial support to their mother.
In 2011, the man also contracted with a freelancer to produce short stories for children that he said were for a website. It is unclear how the stories were used.
In April 2012, the FBI placed Toth on its Ten Most Wanted Fugitives list.
The move brought a fresh wave of attention to his case, because Toth took a spot left empty after the killing of Osama bin Laden and the capture of alleged mobster James "Whitey" Bulger.
The man people identified as Toth seemed to grow bolder. A few months earlier, he freelanced his first blog post for SMBNation, a small-business technology company, under an assumed name, according to people at the company and entries on the blog.
In the months that followed, he contributed regularly to the blog on everything from Facebook's initial public offering to cloud computing and wrote magazine articles.
An online biography sayid he was a "banker once upon a time" but didn't much like it. The biography hints that "there's even more to his story".
"He was refined, very intellectual and geekish," said Bangs, the executive vice president of SMBNation.
"He was someone you might meet at a renaissance fair discussing world civilisations."
Bangs said one thing troubled him in retrospect: SMBNation had given the man a hard drive to review, and the man said he donated it to an elementary school and installed it himself. The man never explained why he did it.
SMBNation booked the man to speak at its October conference. The freelancer was seen as a rising talent, and he appeared to have a future with the company before he missed the speech.
About the same time, Mullen said, the man dropped by another computer store he owned with a surprising announcement.
"He said: I just want to pop in and say goodbye. I'm headed to Nicaragua," Mullen said.
"He said he fancied travelling or something like that. He was vague."
Nicaraguan police said Toth entered the country October 24 using a fake passport.
Anna Graham, an English teacher from Canada, said she met him shortly after at a Managua hotel nestled among palm trees and tropical flowers.
During a small gathering of expatriates one night, he introduced himself as Robert Shaw Walker and said he had come to Nicaragua to write.
He said he was headed to the city of Esteli, a destination Graham thought was odd because it was not particularly popular with tourists.
They went to several movies together in the coming weeks, and nothing seemed amiss. But Graham would make a decision she would come to regret: She invited the man the FBI calls a "child predator" to fill in for her once at a Managua tutoring centre.
"He seemed cool," Graham said.
"In retrospect, I feel really bad."
After Toth's arrest, Graham alerted the director of the centre about his past.
By early April, Toth had been on the run for about five years. Authorities had nearly caught him after he was recognised in Phoenix in 2009, but he remained undercover by shifting identities and locations. Authorities had not publicly acknowledged any other sightings in three years.
But one serendipitous tip would crack open the case.
FBI officials said a tourist who met Toth at a social engagement April 18 recognised him and alerted authorities.
Two days later, Nicaraguan authorities surrounded an orange brick home and removed Toth in handcuffs.
Nicaraguan police said they found no evidence of Nicaraguan victims on a computer Toth had with him.
Among his possessions, they said, were documents for three or four people they think Toth planned to use as aliases. He also had a fake passport.
The FBI would not comment on the status of the investigation. But after Toth's capture, Ronald Machen, US attorney for the District, said authorities "assume there are potential other victims".
Nicaraguan authorities discovered one other item on Toth: A box of eye patches they said he apparently used to conceal a distinct mole under his left eye. It was one of the few aspects of his identity that he hadn't reworked over the years.
"It just blew our minds to find out who he was," said Berg, the director of the Phoenix homeless programme.
"He did a great job at hiding and presenting a different side of himself."
- WASHINGTON POST