Members of the Senate Judiciary Committee on Wednesday vigorously challenged FBI Director Robert S. Mueller III for the bureau's handling of the anthrax mailings investigation, signaling that they were not convinced the case had been solved.
Both the panel's Democratic chairman and its most senior Republican said that, based on what evidence they had seen, the FBI had not proved that the mailings were perpetrated solely by Bruce E. Ivins, the deceased Army scientist who law enforcement officials say committed the crimes.
The anthrax-laced letters were mailed in September and October of 2001 and killed five people. Two of the letters were addressed to members of Congress, including Sen. Patrick J. Leahy (D-Vt.), the chairman of the Judiciary Committee.
Leahy, who shouted with emotion at times during the three-hour hearing, said that if Ivins was "the one who sent the letter, I do not believe in any way, shape or manner that he is the only person involved in this attack on Congress and the American people."
Leahy added: "I believe there are others involved, either as accessories before or accessories after the fact. I believe that there are others out there. I believe there are others who can be charged with murder."
Leahy did not provide the basis for his assertions. Afterward, an aide said the senator would not elaborate. "Based on the complexity of this case and the anthrax that was used, Sen. Leahy still has lingering questions," the aide said.
Leahy's Republican counterpart on the committee, Sen. Arlen Specter of Pennsylvania, criticized Mueller for not opening more investigative details for review -- and he chided the FBI director about the case rolled out so far against Ivins.
"I've looked over a good bit of the evidence on the anthrax case just to contrast prosecutors' opinions," Specter said, apparently referring to his and Mueller's former jobs as prosecutors. "And I have grave doubts about sufficiency of evidence for proof beyond a reasonable doubt."
The hearing was held in a room of the Hart Senate Office Building, which was closed from October 2001 to January 2002 after spores from one of the letters, addressed to then-Senate Majority Leader Tom Daschle (D-S.D.), contaminated the structure. (Daschle has said he is satisfied with the evidence against Ivins.)
For his part, Mueller did not waver. Based on a personal review of the evidence, Mueller said he thought prosecutors could have proven beyond a jury's reasonable doubt that Ivins alone perpetrated the deadly mailings. Mueller also offered to privately provide the senators with additional technical details about the anthrax used in the mailings.
Ivins, 62, committed suicide July 29. His former lawyers have said they would have won his acquittal at a trial.
Another committee member, Sen. Charles E. Grassley (R-Iowa), pressed Mueller on three fronts: the FBI's delay in examining access records showing Ivins' late nights and weekends spent in a special biocontainment lab, where he worked with anthrax; the FBI's misplaced focus from 2002 to 2006 on a former Army virologist, Steven J. Hatfill; and an outside review that Mueller announced this week, which is to focus only on the scientific analyses that traced anthrax from the mailings to Ivins.
Ivins worked as a biodefense scientist at the U.S. Army Medical Research Institute of Infectious Diseases in Frederick, Md.
"There are many unanswered questions the FBI must address before the public can have confidence in the outcome of the case," Grassley said. He called for a "complete accounting of the FBI's evidence."
As for Hatfill, Grassley said, "Please explain how chasing an innocent man for four years was not a mistake." While Grassley spoke, Hatfill watched silently, with his attorney, from the visitors' section.
In response, Mueller said that although the FBI obtained early on the access records reflecting the movements of Ivins and other potential suspects, investigators did not analyze the data until years later, after genetic analyses of the anthrax spotlighted Ivins.
The $5.8-million settlement that the FBI and the Justice Department agreed in June to pay Hatfill was an acknowledgment, Mueller said, that investigative leaks "did harm his reputation. I abhor those leaks."
Times researcher Janet Lundblad in Los Angeles contributed to this report.