From a 9/11 Commission hearing on January 26, 2004, in regards to whether the hijackers entered the U.S. legally, the commission noted: “Two of the surviving passports had been doctored, and the other two had…’suspicious indicators.’ Three hijackers had made false statements on visa applications that could have been detected…and three of those five had violated immigration laws that could have led to their being barred from reentry. …On several occasions, hijackers entering the United States had received greater scrutiny from border officials, and on a number of those occasions the hijackers made false statements. In total, at least six of the nineteen hijackers had violated immigration laws while in the United States.”
– Thomas Kean and Lee Hamilton, Without Precedent, Page 136