FBI, Allied Scientists Describe Analytic Side of Anthrax Investigation

Abstract

A “body of powerful evidence” identifies both “the origin and the perpetrator of the 2001 Bacillus anthracis mailings,” says Vahid Majidi of the Federal Bureau of Investigation (FBI) in Washington, D.C. That series of incidents in 2001 led to five deaths and 17 additional cases of pneumonia— and a massive investigation that, after various twists and turns led FBI officials to name as its prime and final suspect, Bruce E. Ivins, a microbiologist with the U.S. Army Medical Research Institute for Infectious Diseases, Fort Detrick, Md. (USAMRIID), who committed suicide last July. Several weeks later, Majidi, who heads the FBI Weapons of Mass Destruction Directorate, several colleagues from FBI, and several microbiologists and other scientists who helped in analyzing anthrax-related evidence met with reporters in August to summarize scientific findings that link those spores to Ivins, albeit without referring to him directly during their discussions. FBI officials also explicitly declined to discuss other evidence linking Ivins to the 2001 anthrax crimes, restricting discussions to microbial forensics and other more traditional procedures used for analyzing microbial and related materials. Some of those procedures helped in determining that the spores contained “no intentional additives,” despite many reports that they had been chemically altered to be “more dispersible,” Majidi says. Eventual microscopic analysis and X-ray imaging indicate that silicon oxide (silica) associated with the spore samples is on the “inside of the spore coat” and also is found “in vegetative cells,” adds Joseph Michael from Sandia National Laboratories in Albuquerque, N.M., who served as one of many outside analysts for FBI during the investigation.