 After the September 11, 2001, attacks, investigators rapidly accumulated evidence implicating Osama bin Laden.In a taped statement, bin Laden publicly acknowledged his and al-Qaeda's direct involvement in the 9-11 attacks.In an audiotape posted on a website that the U.S. claims is "frequently used by al-Qaeda", on May 21, 2006, bin Laden said he had personally directed the 19 hijackers.