Al-Qaeda Cited Often As Padilla's Trial Opens

The key piece of evidence is a "mujaheddin data form" bearing Padilla's fingerprints and personal information, which prosecutors say was discovered at a reputed al-Qaeda hideout in Afghanistan.

Defense attorneys have attacked the authenticity and origins of the document, advising jurors that expert witnesses have found that the writing on the form came from two inks from two pens.

"The government is really trying to put al-Qaeda on trial in this case, and it doesn't belong in this courtroom," said Jeanne Baker, a lawyer for co-defendant Adham Hassoun.

For all the menace that Padilla seemed to pose five years ago, he is in some ways also a bit player in the trial. His co-defendants, Hassoun and Kifah Jayyousi, appear to have had busier roles in the South Florida support cell that forms the heart of the prosecution.

The cell is charged with sending money and recruits to aid in "violent jihad" movements in Lebanon, Somalia, Kosovo and Chechnya.

Hassoun is described by prosecutors as "the recruiter," Jayyousi as the fundraiser, and Padilla, a recruit.

To build the case, authorities tapped thousands of calls, and a selection of them "will tell the story of the case," according to Frazier.

But Padilla's voice appears on only seven, and his defense attorneys characterized his interaction with the "recruiter" as the innocent conversations between a young man with a troubled marriage, Padilla, and an older man at his mosque, Hassoun. Padilla wanted to become more proficient in Arabic and become an imam, Natale said, so he traveled to Egypt, eventually remarrying a woman there.

In this time "when fear runs high," Natale told jurors, the prosecutors erred by looking at the case through the "goggles of guilt."