February 16, 2011
Experts Cast Doubt On 2001 Anthrax Investigation
A review released Tuesday by a panel of scientific experts casts doubt on FBI evidence that Bruce Ivins, a U.S. Army researcher, committed the deadly anthrax mailings of 2001.
The report by the National Research Council (NRC), part of the National Academy of Sciences, questioned the link between a flask of anthrax bacteria in Ivins' Maryland laboratory and the anthrax-laced letters mailed to lawmakers and members of the news media in New York City and Washington, D.C., which killed five people and sickened 17 others.
The lethal mailings, which came shortly after the September 11 terrorist attacks, shocked the country and resulted in one of the FBI's largest investigations to date.
However, the NRC's review raised serious questions about the Justice Department's conclusion that a single-spore batch of anthrax maintained by Ivins, who killed himself in 2008, was the parent material for the spores used in the attacks.
Instead, the committee found that based solely on the available scientific evidence, it is not possible to reach any definitive conclusion about the origins of the anthrax in the letters.
"There was insufficient scientific evidence to support the FBI's assertion that anthrax sent to politicians and journalists in the wake of the September 11 attacks originated in Ivins' lab," said the National Academy of Sciences.
Investigators agreed with the committee that the spores from the flask would have required one or more intermediary growth steps to become the material used in the letters.
The NRC panel also found that the contents of the New York and Washington letters had different physical properties.
The committee asked to examine the scientific approaches used and conclusions reached by the FBI during its investigation of the mailings. Among the committee's other findings are:
"¢ The FBI correctly identified the dominant organism found in the letters as the Ames strain of B. anthracis.
"¢ Although silicon was present in significant amounts in the anthrax used in the letters, the committee and FBI agree that there is no evidence that the silicon had been added as a dispersant to "weaponize" the anthrax.
"¢ Spores in the mailed letters and in RMR-1029, a flask found at the U.S. Army Medical Research Institute for Infectious Diseases, share a number of genetic similarities consistent with the FBI finding that the spores in the letters were derived from RMR-1029. However, other possible explanations for the similarities -- such as independent, parallel evolution -- were not definitively explored.
"¢ Flask RMR-1029, identified by the U.S. Department of Justice as the "parent material" for the anthrax in the attack letters, was not the immediate source of spores used in the letters. As noted by the FBI, one or more derivative growth steps would have been required to produce the anthrax in the attack letters.
"¢ Although the FBI's scientific data provided leads as to the origin of anthrax spores in the letters, the data did not rule out other possible sources.
"The committee commends the FBI for reaching out to the scientific community for assistance early in the anthrax letters investigation," said Alice Gast, chair of the committee and president of Lehigh University, Bethlehem, Pa.
"We believe this independent review -- done at the FBI's request -- will help strengthen the law enforcement and national security community's scientific and analytical capabilities in future investigations."
The committee advised that realistic expectations and limitations about the use of forensic science should be clearly communicated to the public.
In a statement, the FBI said that the scientific evidence alone did not solve the investigation.
"The scientific findings in this case provided investigators with valuable investigative leads that led to the identification of the late Dr. Bruce Ivins as the perpetrator of the anthrax attacks," the bureau said.
Image Caption: Colin Powell holding a model vial of anthrax while giving a presentation to the United Nations Security Council. Credit: Executive Office of the President of the United States
On the Net:
- The NRC's full report can be accessed here
- National Research Council (NRC)
- U.S. Department of Justice
- National Academy of Sciences
- U.S. Army Medical Research Institute for Infectious Diseases