Paul "Doug" Peters was staying at an apartment complex in La Grange, Kentucky, when he was arrested by a FBI SWAT team, said Elizabeth A. Fries, special agent in charge of the FBI's Kentucky office. La Grange is about 50km northeast of Louisville.
He faces charges in Australia that include kidnapping and breaking and entering, said Luke Moore of the New South Wales Police who are located in Sydney. Moore flew to Louisville for the arrest, but would not go into detail about what led police to Peters.
"There was a range of pieces of evidence that led us to identify this suspect," he said at a news conference at FBI offices in Louisville.
Peters is an Australian citizen but has lived in the US, including Kentucky.
His ex-wife was not at home at the time of the arrest, and there is no indication she is involved in the case, Moore said.
Peters' initial court appearance was set for Tuesday in Louisville and the extradition process will take about two months, Fries said.
The arrest comes nearly two weeks after 18-year-old Madeleine Pulver was attacked in her home in the wealthy Sydney suburb of Mosman as part of an alleged extortion attempt. Peters had been involved in various businesses but would not elaborate.
She was alone when police say 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. Neighbouring homes were evacuated, streets were closed and medical and fire crews waited nearby. Pulver spent 10 terrifying hours chained to the device before the bomb squad was able to free her. She was not hurt, and the device was later found to contain no explosives. Australia's prime minister said the event resembled "a Hollywood script."
Police say a note had been attached to the device, but they haven't released details of what it said. Peters had been involved in various businesses but authorities would not elaborate what they involved.
Moore praised the family and said Pulver is "getting on with her life."
The family had been told of the arrest, Moore said.
"Of course, they are relieved that a suspect has been arrested," he said.
Authorities are still investigating why the suspect targeted the young woman, he said.
Police have said they're treating the case as an extortion attempt. The family lives in one of Sydney's ritziest areas and her father, William Pulver, is CEO of an information technology company.
