He was one of the most beloved teachers in the small world of international schools that serve the children of diplomats, well-off American expatriates and local elites. He was often the first to arrive in the morning, and the last to leave each day. He led students on class trips to exotic places, treating them to cookies and milk at bedtime.
That was the public persona of William Vahey, carefully crafted over four decades -- until a maid cleaning his home in Nicaragua stole a 16-gigabyte memory drive. There, in photograph after photograph, was evidence that the model teacher had molested scores of adolescent boys, possibly far more, in a career spanning 10 schools on four continents.
The FBI said last month at least 90 boys were in the images on the memory drive. The bureau said Tuesday that it has now "been contacted by several hundred individuals from around the globe wishing either to reach out as potential victims or provide information in the ongoing investigation."
The discovery of a man the FBI regards as one of the most prolific pedophiles in memory has set off a crisis in the close-knit community of international schools, where horrified parents are being told their children may have been victims of a favorite teacher, and administrators are scurrying to close teacher-vetting loopholes revealed by Vahey's abuses.
"With the sheer volume, the sheer number of incidents in which this man molested, it surprises me that somehow this was not picked up by someone," said John Magagna, the founding director of Search Associates, the world's largest international school recruiting firm. "I don't know what went wrong."
Apparently not even Vahey's victims knew they had been molested. The double-cream Oreos that he handed out at bedtime on the overnight trips were laced with sleeping pills -- enough to leave the boys unconscious as he touched them, and posed them for lewd photographs.
Vahey, a 64-year-old native of West Point, New York, attempted suicide in Nicaragua after his maid stole the drive. He survived, but killed himself on a second try, stabbing himself to death in Minnesota on March 21 and leaving hundreds of former students wondering if they were abused.
The agonized father of a student in Caracas, Venezuela, said his son, like many others, would rather not find out, but the boy cannot forget one fact. "He ate the cookies, too," said the father, who spoke on condition of anonymity to protect his son's identity. "Everyone on those trips did."
There were decades of missed opportunities to expose Vahey. An early California sex-abuse conviction didn't prevent him taking a series of jobs working with children. Colleagues and supervisors failed to question why he was so often with boys overnight. And at least twice, boys fell mysteriously ill while under his care and there was no investigation into Vahey's role.
In 1969, Vahey, the son of a decorated World War II pilot, was arrested on child sexual abuse charges after police said he pinched the penises of eight boys, ages 7 to 9, at an Orange County high school where he gave swimming lessons.
Vahey, then 20, told authorities he had started touching boys without their consent at age 14, when he fondled a sleeping teen on a Boy Scout camping trip. He said he touched the genitals or anuses of sleeping boys four more times before the arrest.
The psychiatrist diagnosed Vahey with an "inadequate personality," but added that the disorder did not predispose him to sexual offenses dangerous to others. The court even allowed Vahey to start work as a public school teacher's aide after his arrest.
Vahey pleaded guilty to a single charge of lewd and lascivious behavior. He received a 90-day jail sentence and five years' probation, with a condition that he should be supervised in the company of males younger than 16 during that time. After two years on probation, he was allowed to leave the country unsupervised following college graduation in 1972.
Such leniency was common at the time, said Dan Scott, a retired detective sergeant who worked for 26 years with the Los Angeles Sheriff's Department office that investigates child abuse. "Nobody went after sex offenders."
Vahey was required to register as a sex offender and update his address whenever he moved, but he never updated his information after the first time he registered and authorities didn't pursue the matter. When the state registry was put online in 2004, his name wasn't included because authorities discovered he was no longer living in California.