Senator Patrick Leahy says he does not believe that Dr. Bruce Ivins acted alone in the deadly 2001 anthrax attacks.
Leahy is the chairman of the Senate Judiciary Committee and one of the targets of the lethal anthrax-laced letters that killed five and sickened 17 in fall 2001.
Yesterday, Leahy told FBI Director Robert Mueller that he thinks other people must have been involved.
Leahy did not say why he believed Ivins had help and he also cast doubt that the Army scientist was the attacker in the first place.
The Justice Department and FBI have yet to close the case. Prosecutors last month said Ivins was the mastermind and sole attacker.
Ivins killed himself in July after learning that prosecutors were preparing to indict him.