“On October 26, 1988, a [Muslim] Brother named Hashim ‘Abassi was rounded up in the so-called Autumn Leaves arrests in Neuss, Germany. ‘Abassi was part of a cell of Islamic militants that included his brother-in-law and the group’s leader, Muhammad Hafiz Dalkimoni, who were planning to blow up five civilian jetliners. Although ‘Abassi and most of the other Autumn Leaves conspirators were behind bars when Pan Am 103 exploded [on December 21, 1988], the investigators’ initial hypothesis was that they still had something to do with it. The lead was dropped when the investigators settled on two Libyans as the sole culprits. Today we know this was a mistake. If someone had bothered to look into ‘Abassi and his Syrian Muslim Brotherhood cell, we might have been led to the Hamburg cell [that eventually fostered the development of Mohammed Atta and the other Hamburg-based 9/11 hijackers].”
– Robert Baer, Sleeping with the Devil, Page 123