The scientists' report, which will appear in the Journal of Bioterrorism and Biodefense, contends that the anthrax spores sent to two senators and five news organizations in September and October 2001 were complex and precisely manufactured, said Louisiana State University professor emeritus Martin Hugh-Jones, one of the report's authors and a former Fort Detrick researcher himself.
Fort Detrick scientists like Bruce Ivins -- the researcher who killed himself in 2008 as the FBI prepared to file charges against him in connection with the attacks -- wouldn't have been able to produce such highly processed anthrax, Hugh-Jones said. That conclusion raises questions about whether Ivins received help processing the anthrax or was even involved with the attacks, which killed five people and infected 17 others.
"Somebody had to make this material, which is quite complicated," Hugh-Jones said. "They don't do this sort of thing at Fort Detrick. It's foreign to them."
Hugh-Jones, who spent a sabbatical at Fort Detrick in the 1980s, said he knew Ivins and described him as "a very nice guy, a sweet guy."
Hugh-Jones and his colleagues, biologist Barbara Rosenberg and chemist Stewart Jacobsen, based their findings entirely on data from the FBI's own report on the investigation into the anthrax attacks.
They're not the first to challenge the FBI's conclusions in the case. In February, the National Academy of Sciences published a report arguing that the available scientific evidence gathered by the FBI wasn't enough to conclusively determine the source of the anthrax used in the attacks.
The Justice Department stands behind its conclusion that Ivins carried out the attacks on his own, growing anthrax spores with equipment at Fort Detrick, according to a statement released by the department Monday.
"Speculation regarding certain characteristics of the spores is just that -- speculation," the statement read. "Evidence is admissible in a court, speculation is not. We are confident that we would have proven [Ivins'] guilt beyond a reasonable doubt at a criminal trial."
Representatives from Fort Detrick did not return calls seeking comment.