NEW YORK TIMES

WASHINGTON — Senator Patrick J. Leahy,
chairman of the Senate Judiciary Committee and a target of the anthrax
letters of 2001, said Wednesday that he did not believe the F.B.I.’s contention that an Army scientist conducted the attacks alone.

At a hearing of his committee, Mr. Leahy told the F.B.I. director, Robert S. Mueller III, that even if the bureau was right about the involvement of the scientist, Bruce E. Ivins, who killed himself in July before ever being charged, he thought there were accomplices.

“If he is 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,” said Mr. Leahy, Democrat of
Vermont.

“I believe there are others involved, either as accessories
before or accessories after the fact,” he added. “I believe
there are others who can be charged with murder.”

Mr. Leahy, who has received special briefings on the investigation
because one of the anthrax-laced letters was addressed to him, later
declined to elaborate. “Sorry,” said an aide, David Carle,
“but he said his piece and does not intend to comment further
today.”

Mr. Leahy was one of several senators at the hearing who raised
questions about the bureau’s case. But Mr. Mueller said he stood
by the conclusion that Dr. Ivins, who worked at the Army biodefense
laboratory at Fort Detrick, Md., was solely responsible for the attacks.

Even after the anthrax case is formally closed, a step that
officials say is likely in three to six months, “if we receive
additional evidence indicating the participation of any additional
person, we certainly would pursue that,” Mr. Mueller said.

On Tuesday, Mr. Mueller said he had asked the National Academy of Sciences to convene an expert panel to review the bureau’s scientific work on the case.

But Senator Charles E. Grassley,
Republican of Iowa, said Wednesday that he did not think that was
adequate. Mr. Grassley said the academy “would only be reviewing
the science and not the detective work,” and added, “I
believe we need an independent review of both.”

The hearing underscored the challenge the bureau faces in persuading
Congress and the public that the case is resolved. In the audience was Steven J. Hatfill,
another former Army biodefense scientist, whom the F.B.I. pursued as a
suspect for several years before the Justice Department cleared him
this summer and paid $4.6 million to settle a lawsuit he had filed
against the government.

Dr. Hatfill did not speak. But Senator Grassley asked Mr. Mueller:
“Should not the F.B.I. apologize to Dr. Hatfill? Please explain
how chasing an innocent man for four years was not a mistake.”

Mr. Mueller replied that investigators had done nothing
“inappropriate.” The settlement, he said, was not for
scrutinizing Dr. Hatfill but for leaking information about him to the
news media. “I abhor those leaks,” he said.

Mr. Leahy pressed Mr. Mueller to say what laboratories in the United
States were capable of producing dry powder anthrax like that used in
the attacks, specifically asking about the Dugway Proving Ground, an
Army center in Utah, and the Battelle Memorial Institute, a government
contractor in Ohio, both of which have made such powder in small
quantities in the past.

But Mr. Mueller said he could answer the question only in a closed
session because the matter involved classified information. The secrecy
appeared likely to fuel rumors, circulating on the Internet and denied
by the F.B.I., that the attacks had some link to a secret government
bioweapons program.

Mr. Mueller, F.B.I. director since just before the terrorist attacks
of Sept. 11, 2001, was criticized at the hearing by Mr. Leahy and
others for what they described as his record of failing to answer in a
timely manner the committee’s questions on a broad range of
subjects.

But he was praised for what senators characterized as his courage
in resisting some Bush administration counterterrorism tactics,
including harsh interrogation methods and elements of the National Security Agency’s domestic surveillance program.

“Against intense and hostile pressure from the highest offices
in the land,” said Senator Sheldon Whitehouse, Democrat of Rhode
Island, “you stood for the principle that all public offices have
public duties and responsibilities.”