The following is in response to the National Research Council (NRC) of the National Academy of Sciences (NAS) report “Review of the Scientific Approaches Used During the FBI’s Investigation of the 2001 Anthrax Letters” (hereinafter “report”).

“The FBI appreciates the efforts, time and expertise of this group of highly respected professionals of the academy. The academy was asked by the FBI to conduct an independent review in appreciation of the significance of the anthrax investigation and the groundbreaking nature of the science involved and its role in resolving the case. We commend the committee formed by the academy for a report that provides valuable guidance and better prepares the FBI to respond to attacks of a similar nature in the future.

“Among other findings, the committee confirmed the value of the emerging field of ‘microbial forensics,’ which proved significant in solving this case. This scientific technique established a critical lead as to the origins of the anthrax used in the attacks, allowing investigators to focus investigative resources and efforts. Ultimately, the late Dr. Bruce Ivins was determined to be the perpetrator of the deadly mailings. The FBI and Department of Justice were preparing for prosecution at the time of Dr. Ivins’ death.

“As the report recognizes, this was an investigation of almost unprecedented scope, complexity, and duration. Its origins were in the immediate aftermath of the 9/11 attacks when the FBI was unsure of possible links to those attacks and concerned about follow-on attacks. The investigation necessarily moved at a rapid pace, proceeding on two parallel fronts: a traditional investigation, involving tracking leads and conducting interviews, and a scientific one, led by the FBI Lab and included scientists from outside of law enforcement. From the outset, the scientific and traditional investigations were mutually reinforcing. Each helped guide and direct the other. The report notes the complexity of the parallel tracks of the investigation and how aspects of each track informed decisions to proceed with or abandon particular lines of the investigation.

“As the report notes, one of the most significant scientific approaches undertaken in the case—the field of microbial forensics—was being developed as the investigation unfolded. While the biological and chemical analytical methods applied in the investigation were neither new nor unique, the application was both innovative and groundbreaking. The committee’s findings highlight the emerging role that microbial forensics played in this investigation and its promise for future investigations. The report also recognized the FBI’s unprecedented efforts to form outside partnerships within the scientific community and the value that their expertise can lend to a criminal investigation of this magnitude.

“The committee’s report reiterates what is and is not possible to establish through science alone in a criminal investigation of this magnitude. The committee’s focus was on the more novel scientific approaches used in this investigation and did not review the traditional forensic methods and techniques employed or the significant body of evidence gathered through traditional law enforcement techniques. The committee also concluded that 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. The FBI has long maintained that while science played a significant role, it was the totality of the investigative process that determined the outcome of the anthrax case. Although there have been great strides in forensic science over the years, rarely does science alone solve an 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.

“Over the course of the investigation, the FBI and the Postal Inspection Service devoted 600,000 investigator work hours to the case and assigned 17 special agents to a task force, along with 10 U.S. Postal Inspectors. The investigation spanned six continents; involved over 10,000 witness interviews, 80 searches, 26,000 e-mail reviews, and analyses of 4 million megabytes of computer memory; and resulted in the issuance of 5,750 grand jury subpoenas. Additionally, 29 government, university, and commercial laboratories assisted in conducting the scientific analyses that were an important aspect of the investigation.

“The FBI believes that today’s report will increase the public’s understanding of the exhaustive effort that resolved one of the most extensive investigations in the history of the FBI.

“The FBI and Justice Department investigative summary of evidence developed in the ‘Amerithrax’ investigation and numerous attachments are accessible to the public and were posted last year to the Justice Department website at www.justice.gov/amerithrax under the Freedom of Information Act. In addition, roughly 2,700 pages of FBI documents related to the Amerithrax case are accessible to the public and were posted last year to the FBI website at http://foia.fbi.gov/foiaindex/amerithrax.htm under the Freedom of Information Act.”