On October 2 , 2001 ( three days before the first fatality from anthrax in the 2001 domestic US terrorism attacks ) , FBI Agent Gregory Leylegian called and asked Assaad to come in for questioning , which he did the next day . The FBI had received an anonymous letter , postmarked September 21 , 2001 , in which an alleged co-worker warned that Assaad might be planning a biological attack . The timing is noteworthy because anthrax-victim Robert Stevens was not admitted to a Florida hospital until October 2 , and he was not diagnosed with anthrax until October 3 . The first set of letters containing real anthrax were mailed on September 18
terrorism attacks
2001 anthrax attacks
Ayaad Assaad