The American-born woman who calls herself Jihad Jane has been sentenced to 10 years in prison for a failed al-Qa'ida-linked plot to kill a Swedish artist who had depicted the head of the Muslim prophet Mohammad on a dog.
Pennsylvanian divorcee Colleen R LaRose (50), who converted to Islam online, was previously at the centre of a major garda investigation into international terrorism.
She was sentenced yesterday in the US having pleaded guilty to following orders in 2009 from alleged al-Qa'ida operatives.
LaRose, who could have received a life sentence, gave authorities significant help in other terrorism cases since her 2009 arrest, prosecutors told a court in Philadelphia.
She acknowledged her role in a plot with others to kill cartoonist Lars Vilks, who had depicted the head of the Muslim prophet Mohammad on a dog.
LaRose apologised to the court for blindly following instructions of her handlers.
"I was in a trance and I couldn't see anything else," she said.
LaRose, who used the name Jihad Jane as she became involved in the Muslim online community, travelled to Europe in 2009 intending to participate in the plot to shoot the artist in the chest six times.
But she became impatient with the men who lured her to Europe, and she gave up after six weeks and returned to Philadelphia, where she was arrested.
She arrived in Ireland for a two-week visit in September 2009 after spending time in the Netherlands, and while here got in touch with a group she had contacted online. Gardai kept track of her movements and monitored her contact with people here.
The following month she was arrested by US agents when she stepped off a plane in Philadelphia international airport and was taken into custody.
A garda operation resulted in the detention of four men and three women and the seizure of eight computers, mobile phones and documentation for examination.
An Algerian-born Irish citizen, Ali Charaf Damache, who has lived here for more than a decade, is currently fighting an attempt in the courts to extradite him to the US to face terrorism charges. The High Court in Dublin has heard that Mr Damache had made contact with Jihad Jane on the internet.
Assistant US Attorney Jennifer Arbittier Williams had sought "decades behind bars" for LaRose, arguing that despite her extensive cooperation, she still was a danger to society.
Defence lawyer Mark Wilson said the plot to kill Mr Vilks was "more aspirational than operational" and that LaRose had never even fired a gun.
He had described LaRose as a lonely and vulnerable woman easily manipulated by others and said the plot that never moved much past the planning stages.