A 50-year-old man has been arrested at his ex-wife's house and charged with breaking into an Australian home and chaining a fake bomb to a teenager's neck.
Paul 'Doug' Peters was staying in a Louisville, Kentucky, suburb when he was arrested by an FBI commando team.
He faces charges in Australia that include kidnapping and breaking and entering, said Luke Moore of the New South Wales Police.
"There was a range of pieces of evidence that led us to identify this suspect," Mr Moore said.
The arrest comes nearly two weeks after Madeleine Pulver (18) was attacked in her home in the Sydney suburb of Mosman as part of an alleged extortion attempt.
Peters is an Australian citizen but has lived in the US, including Kentucky. Peters' initial court appearance was set for today in Louisville and the extradition process will take about two months, an FBI spokesman said.
The Pulvers were relieved to hear of the arrest. William Pulver described his daughter as "a bright, happy young woman who for reasons we still don't understand had her life turned upside down
"These past two weeks have been a very difficult time for us and we are hopeful that this development marks the beginning of the end of this traumatic ordeal," he told reporters in Sydney.
Peters' ex-wife was not at home at the time of the arrest, and there is no indication she is involved in the case, Mr Moore said. Madeleine Pulver was alone when a masked man broke into the house in the middle of the day, chained a device that looked like a bomb to her and left a note with demands before leaving.
Bomb technicians, negotiators and detectives rushed to the scene. Pulver spent 10 terrifying hours chained to the device before the bomb squad was able to free her. The device was later found to contain no explosives.