Not all the Senators on the Committee took this lying down. According to the Washington Post (Lawmakers Question Results of Anthrax Investigation ):
Senate Judiciary Chairman Patrick Leahy (D-Vermont) told FBI leaders this morning that he does not believe "in any way shape or manner" that lead anthrax suspect Bruce E. Ivins acted alone.
Leahy, an intended recipient of one of the anthrax-packed 2001 letters, publicly cast doubt on the bureau's conclusion last month that the bioweapons researcher carried out the notorious attacks as the sole culprit.
See Salon.com for more (Key senators dispute FBI's anthrax case against Bruce Ivins).
When will the Congress finally stand up and pimp-slap Director Mueller? Leahy seemed mad enough to demand answers; it remains to be seen whether his fellow Congressmen are ready, at long last, to conduct actual oversight of the FBI.