In security screening at Dulles International Airport (Washington, D.C.) on the morning of September 11, 2001, hijacker “Nawaf [al-Hazmi] set off the alarms for both the first and second metal detectors. In his pocket or in his hand luggage he had the heavy Leatherman multitool utility knife he had purchased at the Laurel [Maryland] Target store. But at the time…such a knife was permitted to be carried on board as long as the blade was less than four inches. A screener waved a wand over Nawaf and…let him go without ever bothering to check what set off the alarm.”
– James Bamford, The Shadow Factory, Page 85