Some used false documents to enter the United States; others let their legal visas expire once in the country. And at least 21 foreign nationals became naturalized U.S. citizens before being charged or convicted as terrorists.
In all, at least 94 foreign-born visitors accused of terror activity between 1993 and 2004 exploited federal immigration laws to enter or remain in the United States, according to a study being released Tuesday.
Distributed by the Center for Immigration Studies (search), an advocate for stricter immigration policies, the report provides newly compiled data on U.S. terror arrests to illustrate gaps in the nation's border security, visa approval and immigration systems. It was written by Janice Kephart, who served as counsel to the 9/11 Commission that investigated missteps leading to the Sept. 11, 2001, attacks.
"The attack of 9/11 was not an isolated instance of Al Qaeda (search) infiltration into the United States," the 46-page report found.
"In fact, dozens of operatives both before and after 9/11 — other than the 9/11 hijackers — have managed to enter and embed themselves in the United States, actively carrying out plans to commit terrorist acts against U.S. interests or support designated foreign terrorist organizations," the report concluded. "For each to do so, they needed the guise of legal immigration status to support them."
Overall, 59 of 94 foreign-born nationals who were either convicted or indicted on terror charges broke federal immigration laws to enter or remain in the country between 1993 and 2004, the report found. It also noted:
_Twenty-two of the 94 either had student visas or other applications approving them to study in the United States; another 17 used visitor visas to enter the country.
_In at least 13 instances, suspected and convicted terrorists overstayed their temporary visas.
_Seven of the 94 were indicted for using false driver's licenses, birth certificates, Social Security cards and immigration records.
_Twenty-one became naturalized citizens.
The report identified many of the immigrants as affiliated with at least one terror organization, including 40 with al-Qaida, 16 with Hamas, 16 with the Palestinian or Egyptian Islamic Jihad, and six with Hezbollah.
Tightening U.S. borders has become a top priority for Homeland Security Secretary Michael Chertoff (search), who last week called immigration enforcement an issue of utmost importance. The Homeland Security Department has enacted a slew of programs, including stricter background checks, visa security systems and sharing intelligence with international allies, to harden immigration laws against terrorists, spokesman Russ Knocke said.
Since June 2003, the department has investigated 7,100 cases of immigrants suspected of violating temporary visas, resulting in 1,339 arrests, Knocke said.
New department programs "and others would have placed a significantly greater amount of scrutiny on the 9/11 hijackers, vastly improving the odds of stopping them before they could have completed their attacks," Knocke said.
Recent studies indicate immigration-related cases made up for nearly 33 percent of all federal prosecutions last year, more than any other crime.
A spokesman for the National Immigration Forum, an immigration advocacy group, did not immediately return telephone calls seeking comment Monday evening.