Dean Lewins / EPA, file

Detectives drive collar bomb suspect Paul Peters from Sydney International Airport in September 2011, after he was extradited from the U.S.

A man who strapped a fake bomb around the neck of a Sydney schoolgirl and then fled to the United States was jailed for 13 and a half years on Tuesday after an Australian court ruled he had instilled unimaginable fear into his victim.

The case sparked an international manhunt and led to a tense 10 hours for teenager Madeleine Pulver, 18, after the man broke into her family's luxury home in August 2011 and chained what he said was a bomb around her neck, leaving a note demanding money.

After extensive tests, bomb technicians determined the box was harmless.

Police in the United States arrested Paul Douglas Peters, 52, in Kentucky at his former wife’s home about two weeks after the incident by tracking him through email accounts. In September 2011 he was extradited to Australia.

'Collar bomb' extortion case: Banker who fled to Kentucky pleads guilty

Defense lawyers said Peters had suffered depression in the months before the attack and had no memory of his actions. Prosecutors said Peters had planned to target a neighbor of the Pulver family, and broke into the wrong house.

"He would have appreciated the enormity of what he was doing and the terrible effect and consequences of his actions on the victim," Sentencing District Court Judge Peter Zahra said. "The fear instilled can only be described as unimaginable."

He sentenced Peters, who pleaded guilty to “aggravated break and enter”, to 13 years and six months in prison, with a minimum 10 years to be served before he can apply for parole.

Before the attack, Peters was the CEP of Appen Butler Hill, a company that provides language and voice-recognition software and services.

Outside the court, Pulver said she was pleased Peters would not be able to hurt anyone else, and that the court acknowledged the impact of his crime on her family.

"It was good to hear the judge acknowledge the trauma (Peters) has put my family and me through," said Pulver, who plans to attend university in Sydney next year. "It's been a surprise to me that this year has been much harder than last year, but I’m lucky enough to have a wonderful family and friends and we are all making great progress.”

Reuters contributed to this report.

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