In testimony before Congress on May 8, 2002, FBI director Robert Mueller said: ” ‘The [9/11] hijackers also apparently left no paper trail. In our investigation, we have not yet uncovered a single piece of paper–either here in the U.S. or in the treasure trove of information that has turned up in Afghanistan and elsewhere–that mentioned any aspect of the September 11th plot.’ And yet, as this book [Triple Cross] has documented, the paper trail was significant–from [World Trade Center bomber] Ramzi Yousef’s 1993 pledge to return to hit the Towers, to the detailed evidence of the ‘planes [as missiles] operation’ on Yousef’s Toshiba laptop, which had been in federal custody since 1995.”
– Peter Lance, Triple Cross, Page 445