After the 1993 World Trade Center bombing took place , his research area changed to terrorist attacks . In the following years he was involved with the research of the 1998 United States embassy bombings in Tanzania and Kenya , the 2000 USS '' Cole '' bombing in Aden , Yemen , and the destructive attacks of September 11 , 2001 , on the World Trade Center and The Pentagon . In course of the years he therefore became an expert on al-Qaeda
attacks of September 11 , 2001
September 11 attacks
Pasquale J. D'Amuro