Attorney General Eric H. Holder Jr. (left), accompanied by FBI Director Robert S. Mueller III, announces on Tuesday, Oct. 11, 2011, in Washington that two men have been charged in an alleged plot directed by elements of the Iranian government to murder the Saudi ambassador to the United States. (AP Photo/Haraz N. Ghanbari)

Photo by: Haraz N. Ghanbari

Attorney General Eric H. Holder Jr. (left), accompanied by FBI Director Robert S. Mueller III, announces on Tuesday, Oct. 11, 2011, in Washington that two men have been charged in an alleged plot directed by elements of the Iranian government to murder the Saudi ambassador to the United States. (AP Photo/Haraz N. Ghanbari)