FBI lab reports on anthrax attacks suggest another miscue - McClatchy Newspapers

Could someone other than the late Bruce Ivins be the real anthrax killer? | Photo courtesy U.S. Army Medical Institute

By Greg Gordon | McClatchy Newspapers

WASHINGTON — Buried in FBI laboratory reports about the anthrax mail
attacks that killed five people in 2001 is data suggesting that a
chemical may have been added to try to heighten the powder's potency, a
move that some experts say exceeded the expertise of the presumed
killer.

The lab data, contained in more than 9,000 pages of files that
emerged a year after the Justice Department closed its inquiry and
condemned the late Army microbiologist Bruce Ivins as the perpetrator,
shows unusual levels of silicon and tin in anthrax powder from two of
the five letters.

Those elements are found in compounds that could be used to
weaponize the anthrax, enabling the lethal spores to float easily so
they could be readily inhaled by the intended victims, scientists say.

The existence of the silicon-tin chemical signature offered
investigators the possibility of tracing purchases of the more than 100
such chemical products available before the attacks, which might have
produced hard evidence against Ivins or led the agency to the real
culprit.

But the FBI lab reports released in late February give no hint that
bureau agents tried to find the buyers of additives such as
tin-catalyzed silicone polymers.

The apparent failure of the FBI to pursue this avenue of
investigation raises the ominous possibility that the killer is still
on the loose.

A McClatchy analysis of the records also shows that other key
scientific questions were left unresolved and conflicting data wasn't
sorted out when the FBI declared Ivins the killer shortly after his
July 29, 2008, suicide.

One chemist at a national laboratory told McClatchy that the
tin-silicone findings and the contradictory data should prompt a new
round of testing on the anthrax powder.

A senior federal law enforcement official, who was made available
only on the condition of anonymity, said the FBI had ordered exhaustive
tests on the possible sources of silicon in the anthrax and concluded
that it wasn't added. Instead, the lab found that it's common for
anthrax spores to incorporate environmental silicon and oxygen into
their coatings as a "natural phenomenon" that doesn't affect the
spores' behavior, the official said.

To arrive at that position, however, the FBI had to discount its own
bulk testing results showing that silicon composed an extraordinary
10.8 percent of a sample from a mailing to the New York Post and as
much as 1.8 percent of the anthrax from a letter sent to Democratic
Sen. Patrick Leahy of Vermont, far more than the occasional trace
contamination. Tin — not usually seen in anthrax powder at all — was
measured at 0.65 percent and 0.2 percent, respectively, in those
letters.

An FBI spokesman declined to comment on the presence of tin or to answer other questions about the silicon-tin connection.

Several scientists and former colleagues of Ivins argue that he was a
career biologist who probably lacked the chemistry knowledge and
skills to concoct a silicon-based additive.

"There's no way that an individual scientist can invent a new way of
making anthrax using silicon and tin," said Stuart Jacobsen, a
Texas-based analytical chemist for an electronics company who's closely
studied the FBI lab results. "It requires an institutional effort to
do this, such as at a military lab."

Martin Hugh-Jones, a world-renowned anthrax expert who teaches
veterinary medicine at Louisiana State University, called it "just
bizarre" that the labs found both tin — which can be toxic to bacteria
such as anthrax during lab culturing — and silicon.

"You have two elements at abnormally high levels," Hugh-Jones said.
"That reduces your probability to a very small number that it's an
accident."

The silicon-tin connection wasn't the only lead left open in one of
the biggest investigations in FBI history, an inquiry that took the
bureau to the cutting edge of laboratory science. In April, McClatchy
reported that after locking in on Ivins in 2007, the bureau stopped
searching for a match to a unique genetic bacterial strain scientists
had found in the anthrax that was mailed to the Post and to NBC News
anchor Tom Brokaw, although a senior bureau official had characterized
it as the hottest clue to date.

FBI officials say it's all a moot point, because they're positive
they got the right man in Ivins. A mentally troubled anthrax researcher
at the U.S. Army Medical Research Institute of Infectious Diseases at
Fort Detrick, Md., Ivins overdosed on drugs not long after learning
that he'd soon face five counts of capital murder.

In ending the inquiry last year, the Justice Department said that a
genetic fingerprint had pointed investigators to Ivins' lab, and
gumshoe investigative techniques enabled them to compile considerable
circumstantial evidence that demonstrated his guilt.

Among these proofs, prosecutors cited Ivins' alleged attempt to steer
investigators away from a flask of anthrax in his lab that genetically
matched the mailed powder — anthrax that had been shared with other
researchers. They also noted his anger over a looming congressional cut
in funds for his research on a new anthrax vaccine.

However, the FBI never found hard evidence that Ivins produced the
anthrax or that he scrawled threatening letters seemingly meant to
resemble those of Islamic terrorists. Or that he secretly took
late-night drives to Princeton, N.J., to mail them.

The FBI declared Ivins the killer soon after paying $5.8 million to
settle a suit filed by another former USAMRIID researcher, Steven
Hatfill, whom the agency mistakenly had targeted earlier in its
investigation.

Anthrax is one of the deadliest and most feared biological weapons.
Once inhaled, microscopic anthrax spores germinate into rapidly
multiplying, highly toxic bacteria that attack human tissue. The
resulting illnesses are lethal within days if untreated.

The letters, mailed just weeks after the Sept. 11 terrorist attacks,
not only went to the New York Post, Leahy and Brokaw, but also to
American Media Inc. in Boca Raton, Fla., and to Democratic then-Sen.
Tom Daschle of South Dakota. Five people died, 17 were sickened and
about 31,000 were forced to take powerful antibiotics for weeks. Crews
wearing moon suits spent several weeks eradicating the spores from a
Senate office building and a central Postal Service facility in
Washington.

The FBI guarded its laboratory's finding of 10.8 percent silicon in
the Post letter for years. New York Democratic Rep. Jerrold Nadler
asked FBI Director Robert Mueller how much silicon was in the Post and
Leahy letters at a hearing before the House Judiciary Committee in
September 2008. The Justice Department responded seven months later
that silicon made up 1.4 percent of the Leahy powder (without
disclosing the 1.8 percent reading) and that "a reliable quantitative
measurement was not possible" for the Post letter.

The bureau's conclusions that silicon was absorbed naturally drew a
gentle challenge in February from a panel of the National Academy of
Sciences, which evaluated the investigation's lab work.

While finding no evidence that silicon had been added to the mailed
anthrax, the panel noted deep in its report that the FBI had provided
"no compelling explanation" for conflicts in silicon test results
between the Sandia National Laboratories and its own lab.

Sandia — which used electron microscopes, unlike the FBI — reported
only a tenth as much silicon in the New York Post letter as the
bureau's lab did. Sandia said it was all embedded in the spore
coatings, where it wasn't harmful.

The Armed Forces Institute of Pathology ran a third set of tests and
found pockets of heavy silica concentrations, but it couldn't say
whether they were inside or outside the spores.

Jacobsen, the Texas chemist, suspects that the silica pockets
represented excess material that went through a chemical reaction and
hardened before it could penetrate the spores.

The National Academy of Sciences panel wrote that the varying
composition of the powder might have accounted for the differing
findings.

While finding no evidence that silicon was added, the panel said it
"cannot rule out the intentional addition of a silicon-based substance
... in a failed attempt to enhance dispersion" of the New York Post
powder.

Tufts University chemistry professor David Walt, who led the panel's
analysis of the silicon issue, said in a phone interview that "there
was not enough silicon in the spores that could account for the total
silicon content of the bulk analysis."

He said it was unclear whether the "trace" levels of tin were significant.

During the FBI's seven-year hunt, the Department of Homeland Security
commissioned a team of chemists at the Lawrence Livermore National
Laboratory in California to grow anthrax-like spores under varying
conditions to see how much silicon would end up naturally in the final
product.

They found little, if any, silicon in most cases, far less than was
in the New York Post letter, said Stephan Velsko, one of the two
researchers. He called the tin readings from the FBI's anthrax data
"baffling."

Peter Weber, Velsko's co-researcher, said the academy panel's focus
on the conflicting data "raises a big question," and "it'd be really
helpful for closure of this case if that was resolved."

He suggested that further "micro-analysis" with a highly
sophisticated electron microscope could "pop the question marks really
quickly."

In a chapter in a recently updated book, "Microbial Forensics,"
Velsko wrote that the anthrax "must have indeed been produced under an
unusual set of conditions" to create such high silicon counts. That
scenario, he cautioned, might not be "consistent with the prosecution
narrative in this case."

About 100 tin-catalyzed silicone products are on the market, and an
even wider array was available in 2000 and 2001, before the mailings,
said Richie Ashburn, a vice president of one manufacturer, Silicones
Inc., in High Point, N.C.

Mike Wilson, a chemist for another silicone products maker, SiVance,
in Gainesville, Fla., said that numerous silicon products could be
used to make spores or other particles water-repellent. He also said
that the ratios of silicon to tin found in the Post and Leahy samples
would be "about right" if a tin-catalyzed silicone had been added to
the spores.

Jacobsen, a Scottish-born and -educated chemist who once
experimented with silicon coatings on dust particles, said he got
interested in the spore chemistry after hearing rumors in late 2001
that a U.S. military facility had made the killer potions. He called it
"outrageous" that the scientific issues haven't been addressed.

"America, the most advanced country in the world, and the FBI have
every resource available to them," he said. "And yet they have no
compelling explanation for not properly analyzing the biggest forensic
clue in the most important investigation the FBI labs had ever gotten
in their history."

As a result of Ivins' death and the unanswered scientific issues,
Congress' investigative arm, the Government Accountability Office, is
investigating the FBI's handling of the anthrax inquiry.

(Tish Wells contributed to this article.)