The blonde middle-aged woman apparently raised no concerns with her boyfriend or her neighbours on Main Street, Pennsburg, near Philadelphia.
But online she had allegedly agreed to kill in the name of holy war, believing her European looks would allow her to blend in among Swedes as she homed in on her target.
Colleen LaRose, according to a US court indictment, posted messages online under the name Jihad Jane, expressing her desire to participate in jihad, or holy war.
Arrested in October 2009, Ms LaRose had exchanged emails over 15 months to recruit fighters for "violent jihad".
Her activities apparently came as a surprise to her boyfriend Kurt Gorman, whom she met in 2005.