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McClatchy Points Out Key FBI Failure in Amerithrax Investigation

5:58 am in Uncategorized by Jim White

The infamous RMR-1029 flask. Where is the B. subtilis flask?

In an article published Wednesday evening on their website, McClatchy points out yet another failing in the FBI’s Amerithrax investigation of the 2001 anthrax attacks that killed five people. The article focuses on the fact that the FBI was able to get a clear genetic fingerprint of a bacterial contaminant that was found in the attack material mailed to the New York Post and to Tom Brokaw (but not to either Senator Daschle or Senator Leahy). This contaminant, Bacillus subtilis, is used in some cases by weapons laboratories as an anthrax simulant, because its behavior in culture and in drying the spores is very similar to Bacillus anthracis but it is easier to handle because it is not pathogenic.  I covered the FBI’s failure to link this B. subtilis contaminant to Ivins in this diary in February of 2010.

A key finding in the McClatchy article comes from an FBI memo they obtained:

One senior FBI official wrote in March 2007, in a recently declassified memo, that the potential clue “may be the most resolving signature found in the evidence to date.”

The genetic fingerprint of the B. subtilis contaminant, in other words, was a very definitive clue that needed to be traced to the culprit. The problem, as McClatchy points out, is that the FBI never got a match to materials from Ivins or from anyone else:

Yet once FBI agents concluded that the likely culprit was Bruce Ivins — a mentally troubled, but widely regarded Army microbiologist — they stopped looking for the contaminant, after testing only a few work spaces of the scores of researchers using the anthrax strain found in the letters. They quit searching, despite finding no traces of the substance in hundreds of environmental samples from Ivins’ lab, office, car and home.

LSU anthrax researcher Martin Hugh-Jones makes the key point in his discussion with McClatchy, in response to being informed the government tested thousands of samples for a match to the B. subtilis contaminant, “But were they thousands of the right samples?”

The significance of B. subtilis being present in some of the attack material cannot be overstated, especially when the FBI admits that they were able to obtain a unique DNA fingerprint of the strain that was present. As I wrote last year, I suspect that Defense Department personnel at either Dugway or Batelle cultured the material used in the attacks and noted personnel there have worked with both anthrax and B. sublitlis:

Even though Ivins can’t be linked to the particular B. subtilis strain used, there is a documented case of B. subtilis being used as a B. anthracis simulant at another facility where we already know that much of the material that went into RMR-1029 was produced. Recall from this diary that I analyzed the available information about the amount of B. anthracis used in the attacks and found it highly unlikely that Ivins could have cultured the large amount of spores used in the attacks with the equipment and time he had available. Much of the material in RMR-1029 was produced at Dugway.

On December 13, 2001, Judith Miller published an article in the New York Times, where she disclosed that “government officials have acknowledged that Army scientists in recent years have made anthrax in a powdered form that could be used as a weapon.” She further pointed out that this work occurred at Dugway in 1998. It should be noted that the anthrax produced at Dugway for Ivins that went into RMR-1029 was cultured in 1997.

The Miller article then goes on to quote scientist William C. Patrick on how he coached scientists at Dugway in drying a pound of highly purified anthrax spores in 1998. Miller quotes a Dugway spokesperson as saying a strain different from Ames (the parent of RMR-1029) was used in the drying experiments. Note that a pound of spores is enough dried spores to produce hundreds of letters with the one to two grams of dried spores thought to be in each letter. But in a further bit from the Dugway spokesperson, we have this:

She said Dugway did make one- pound quantities of Bacillus subtilis, a benign germ sometimes used to simulate anthrax.

We know that the key anthrax work at Dugway and Batelle was carried out by the Defense Intelligence Agency. I find it highly unlikely that this agency would be completely forthcoming with the FBI in sharing samples of all of the B. anthracis or B. subtilis strains in its collection, so Hugh-Jones was right to question whether the FBI tested the right samples for a match to the key B. subtilis contaminant. The fact that all of Ivins’ materials were available to the FBI, and that the FBI was able to carry out extensive environmental sampling (albeit several years after the preparation of the attack materials) where Ivins worked and lived comes very close to excluding Ivins as a suspect since the contaminant was not found in association with him.

Buried in the McClatchy article is an admission from a source close to the investigation that seems to shed some light on why the FBI continues to insist that Ivins was the sole attacker, even going so far as to concoct an after-the-fact “forensic psychiatric profile” in an effort to bolster their case:

“If they ever had any doubts, once he committed suicide, they had to unite,” this person said. “Otherwise, you’ve driven an innocent man to suicide. And that’s a terrible thing.”

Yes, driving a man to suicide is a terrible thing. But is it any less terrible to continue to insist on the guilt of a man who cannot conclusively be proven to have carried out these horrendous attacks ten years ago?

Would the NAS Report Have Led to Reasonable Doubt in an Ivins Trial?

12:02 pm in Uncategorized by Jim White

FBI photos of the material in the letter sent to Senator Pat Leahy (left) and to the New York Post (right), from the report.

It seems very likely to me that had Bruce Ivins not died, the analysis carried out by a panel from the National Academy of Sciences in assessing the scientific evidence tying Ivins to the 2001 anthrax attacks would have led to reasonable doubt on whether Ivins carried out the attacks. For this post, let us concentrate only on the NAS response to FBI claims on the spores used in the attack, especially with regard to how the spores were prepared.

What we do know from the report is that the spores used in the attacks did not come directly from Bruce Ivins’ RMR-1029 flask, but had to undergo a culturing step if RMR-1029 was even the source. Also, the spore material in different individual mailings differed in purity and particle size.  Silicon was present in the spores, but was not added as a step to “weaponize” the spores.  Instead, the silicon was incorporated into the coating of the spores themselves.   Finally, the NAS panel did not feel there was sufficient evidence to support the FBI claim that a highly skilled person had prepared the material.

Overall, the importance of the primary conclusion of the NAS report cannot be overstated (p. 4 of the report as marked, all references will use internal page numbers, not pdf numbers from my pre-publication copy):

It is not possible to reach a definitive conclusion about the origins of the B. anthracis in the mailings based on the available scientific evidence alone.

A good defense attorney probably would need no more than that conclusion to establish reasonable doubt in a trial.  But the details on how the panel reached that conclusion are important.

In this post, I discussed whether Ivins could have produced all of the material used in the attacks with the equipment he had available and without drawing attention to himself.  That post opened with a discussion of how many spores were known to have been present in the attacks.  I looked at what was in the FBI’s report, filled in some gaps with my experience in microbiology and came to the conclusion that somewhere between four and seventy liters of liquid culture could have produced the attack material.  The NAS report comes to a similar conclusion on page 62:

Thus, cultivation in the range of 2.8 to 53 liters of liquid medium would have been required to produce the spores required for the letters (see Table 4.2).

Interestingly, the panel also calculated that it would have required between 463 and 1250 agar plates if the attack material had been produced on solid medium.  It seems highly unlikely Ivins could have cultured this many extra Petri dishes without someone in the lab taking note and reporting it to the FBI once the investigation began.

The photo above shows how dramatically different the highly purified material in the letter sent to Senator Patrick Leahy’s office was when compared to the material mailed to the New York Post.

There had been much speculation early on in the press that the material sent to Senator Leahy’s office had been “weaponized” by the addition of materials including silicates to make tiny particles remain suspended in the air so that they could be inhaled.  The report documents that although silicon is found in the spores used in the attacks, the silicon is localized in the spore coats.  This point is driven home very clearly in this photo, where the silicon can be seen “lighting up” within the outer lining of the spores:

Many experiments were carried out in an attempt to match the silicon content, the particle size distribution and the degree to which the final material would remain suspended in air.  I will rely here on the entire summary the panel provided on the issue of silicon in the spores (page 71):

The substantial effort devoted to the characterization of silicon in Bacillus spore coats resulted in new fundamental insight into microbial processes and the development of new or enhanced analytical measurement technology. (Table 4.4 presents a summary of the analytical results.) Elemental analysis of the letter samples showed that 1) the silicon content was high, 2) most of the silicon was incorporated in the spore coat, 3) the majority of spores in the samples contained silicon in the coat, and 4) no silicon was detected in the form of a dispersant in the exosporium.

The bulk silicon content in the Leahy letter could be completely explained by the amount of silicon incorporated in the spores during growth. (Not enough material was available to make this comparison for the Daschle letter.) In contrast, the New York Post letter had significant bulk silicon content, far exceeding that contained in the spores.

No studies have considered the effect of the chemical form of silicon (e.g., silicate impurity versus polydimethylsiloxane antifoam agent) on uptake. The inability of laboratory experiments to reproduce the silicon characteristics of the letter samples is not surprising given the complexity of the uptake mechanism.

A few spores analyzed from RMR-1030 contained silicon in the coat, but none of the spores analyzed from RMR-1029 contained silicon in the coat. Therefore, the letter samples could not have been taken directly from the flasks—a separate growth preparation would have been required.

The material in the Daschle and Leahy letters was reported to have “a high level of purity” and to have electrostatic properties that caused it to disperse readily upon opening of the letters. These properties should be regarded as qualitative observations since they were not based on quantitative physical measurements. The committee received testimony (Martin, 2010) stating that some Dugway preparations, particularly those utilizing lyophilization but no dispersant, gave products with similar appearance and electrostatic dispersibility as the letter samples, suggesting that these properties were not necessarily connected to an intentional effort to increase dispersibility through addition of a dispersant. Exogenous silicon and bentonite, which enhance the dispersibility of spore preparations, were not found in the Leahy and Daschle letters.

Note that this analysis provides the strongest evidence to date that the spores used in the attacks did not come directly from the RMR-1029 flask, because the spores in the flask do not have the silicon content as those in the attack material. Note also that growth in the presence of polydimethylsiloxane-containing antifoam agents is seen as one route that needs to be investigated for how silicon can be incorporated at elevated concentration in the spores, just as I suggested in this post.

It is also worth noting that highly purified spores produced at Dugway did have the aerosolizing quality of the attack material. No additional treatments besides purification were needed for these spores to disperse in air, so I suspect that is one of the primary reasons that the NAS panel could not support the FBI claim that someone with a very high level of expertise must have prepared the material used in the attacks.