After the attacks , the identification of Mihdhar was one of the first links suggesting that bin Laden had played a role in their organization , since Mihdhar had been seen at the Malaysian conference speaking to bin Laden 's associates . The FBI interrogated Quso , who was arrested following the USS '' Cole '' bombing and in custody in Yemen . Quso was able to identify Mihdhar , Hazmi and Attash in photos provided by the FBI , and he also knew Marwan al-Shehhi , a hijacker aboard United Airlines Flight 175 . From Quso , the FBI was able to establish an al-Qaeda link to the attacks
United Airlines Flight 175
United Airlines Flight 175
Khalid al-Mihdhar