Three scientists are challenging the FBI’s conclusion that the 2001 deadly anthrax attacks were solely the work of a Fort Detrick researcher, and they’re set to publish their findings in a major scientific journal next month. 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.