http://www.cis.org/articles/2005/kephart.html
"This report covers the immigration histories of 94 terrorists who operated in the United States between the early 1990s and 2004, including six of the September 11th hijackers. Other than the hijackers, almost all of these individuals have been indicted or convicted for their crimes. The report builds on prior work done by 9/11 Commission and the Center for Immigration Studies, providing more information than has been previously been made public"
