Immigration Law as Anti-Terrorism Tool

Tehseen said the group had seemed to be a legitimate charity. But last October, the Treasury Department accused the agency's overseas branches of helping fund Osama bin Laden.

Several of Tehseen's colleagues defended her assertion that she was interested in charity, not Islamic radicalism. Federal prosecutors, however, apparently believed Tehseen could provide information. She said federal agents questioned her about the Islamic charity, the Taliban and al Qaeda, and authorities offered to go easy on her immigration-fraud charge if she became an informant.

Federal officials declined to comment on that investigation, saying the information is classified. An official close to the case, who spoke on the condition of anonymity, confirmed that a deal was discussed but provided no details.

Tehseen declined the offer because, she said, "I'm not an FBI person who can go and sneak in and find out who's right and wrong." She was deported last August and is working on environmental projects in Pakistan.

Muslim activists say cases such as Tehseen's show that the government is scouring the immigration papers of Arabs and Muslims it considers suspicious.

"They see people they want to get, [and] they look in their records until they find something they can get them on," said Arsalan Iftikhar, legal director of the Council on American-Islamic Relations.

Homeland Security officials say they are not focusing on any ethnic or religious group.

"We're targeting people who our investigation shows are involved in some type of activity" that could jeopardize national security, Garcia said.

ICE officials say they have used immigration laws to take dangerous people off the streets. For example, Nuradin Abdi, a Somali immigrant living in Ohio, was locked up on an asylum-fraud charge in November 2003. He was subsequently charged with plotting with an al Qaeda member to blow up a shopping mall. He has pleaded not guilty.

ICE officials also point to cases in which they have deported active supporters of terrorist groups, including at least two men who had attended guerrilla training camps in Pakistan.

All cases with a terrorism connection are handled through the FBI-led Joint Terrorism Task Forces, ICE officials said.

Authorities say they sometimes turn to immigration charges rather than terrorism charges because a case might be based on classified information that they cannot reveal in court without damaging other investigations. Sometimes they face other legal barriers.