Colorado mother Jamie Paulin-Ramirez was released from custody in Ireland after being arrested in a plot to kill a Swedish cartoonist who angered many Muslims by portraying Mohammed with a dog's body.
Authorities are still holding three other suspects in that alleged plot, including Paulin-Ramirez' husband and Colleen Larose, who allegedly called herself "Jihad Jane" online.
Though Paulin-Ramirez was released, her mother said in an interview with ABC News that the 31-year-old woman had been troubled for years, was taunted as a child over a hearing problem and the family was concerned that she had become radicalized.
"Just a very insecure, unhappy person that was just looking for something to hang onto, I guess," Christine Mott said.
After a string of failed marriages, Mott said, Paulin-Ramirez married a Muslim and began covering up her blonde hair and face and hands with a scarf and gloves, leaving only a narrow slit for her eyes.
When her stepfather asked if she would strap a bomb to her chest, her mother said that Paulin-Ramirez replied, "If necessary."
"It breaks my heart," Mott said. "I don't understand why she would turn her back on her country, turn her back on her family."
Asked if her daughter was capable of participating in a lethal plot, Mott added, "I would like to believe that she's not capable of it, but right now I don't know who or what she is anymore. It's possible."
While Paulin-Ramirez was freed, Larose, a blond, blue-eyed Pennsylvanian, was indicted in the alleged plot to kill cartoonist Lars Vilks. It is just one of several alleged home-grown terror conspiracies.
"Individuals like this 'Jihad Jane' -- a blond-haired woman from the United States, U.S. citizen -- defy our stereotype of what a terrorist is," Rick Nelson of the Center for Strategic and International Studies told ABC News.
Sharif Mobley, a New Jersey man who had worked at half a dozen nuclear plants, was arrested as a suspected radical in Yemen and later shot a hospital guard during an alleged escape attempt. The case set off alarm bells, leading Sen. Chuck Schumer on Saturday to call for a review of the background checks given to employees at U.S. nuclear plants.
There is growing indication that willing Americans and others living in the United States are plotting attacks at home and abroad. Among them:
Nidal Hasan of Virginia, the alleged fort hood bomber.
Najibullah Zazi of Denver, who pleaded guilty to planning an attack on new York's Subway system.
And David Headley of Chicago, accused of conducting surveillance ahead of the Mumbai terror attacks.
Most showed signs of alienation. Like Paulin-Ramirez, the woman known as "Jihad Jane" was divorced. Police say she attempted suicide after her father's death and later converted to Islam.
Many of the accused conspirators found a radical community online.
"If they are disenfranchised, if they do feel they have some sort of grudge against the government, they will find venues or forums where they can find like-minded individuals," Nelson said.
Some alleged conspirators have a common link. Hasan and Mobley were both reportedly in contact with radical Yemeni cleric Anwar al-Awlaki, a man increasingly the focus of U.S. intelligence agents.