Vahey said he had swallowed more than 100 sleeping pills in November after discovering the USB drive had been taken.
Doll demanded Vahey's resignation, according to the affidavit.
Vahey flew to Atlanta the next day. It was only after he boarded that the school notified authorities at the U.S. Embassy in Managua, U.S. officials said. The U.S. officials immediately notified Nicaraguan police, but Vahey had left the country.
In Miami, where he changed planes, a special agent from the FBI notified Vahey of the investigation. But a bag check turned up nothing illegal, and the agents had no grounds on which to hold him.
By March 14, the school told parents Vahey had resigned. The teacher traveled to Luverne, Minnesota, where his brother, sister-in-law and mother live, the latter in a nursing home. He checked into a hotel where he fatally stabbed himself in the chest with a knife.
He left a note apologizing to his family.
"He's one of the most prolific pedophiles that we've seen here due to the sheer numbers," FBI Special Agent Sharon Dunlap said.
At least 60 of the 90 or so children in the images were from the Southbank school, according to police, where a significant number of parents said they did not want to know if their children were abused. Woodhead, the governor, has blamed the U.S. system.
"How did he qualify as a teacher in the United States, how is it this information was never available to any of the schools across the world who employed him over the next 40 years?" he asked in an interview with the Press Association.
In Venezuela, students are coming forward with details that suggest they may have been abused.
"We don't know who was drugged. Right now we're just listening," superintendent Hedger said. "There's an enormous sense of betrayal ... He was one of the most popular, if not the most popular, teachers in the school."