The 2001 Anthrax Attacks

In the weeks following the September 11 attacks, letters containing dried anthrax spores were mailed to the offices of several news media outlets and to two Democratic U.S. senators — Tom Daschle and Patrick Leahy — killing five people and infecting seventeen others. The attacks caused massive disruption: the Hart Senate Office Building was closed for decontamination for three months, and postal facilities along the Eastern Seaboard required extensive remediation. It was the first significant bioterrorism attack on American soil. The FBI's investigation, known as "Amerithrax," became one of the longest and most complex in the bureau's history. For years, investigators focused on Steven Hatfill, a former Army biodefense researcher, who was extensively surveilled and publicly named as a "person of interest" by then-Attorney General John Ashcroft. Hatfill was eventually cleared and received a $5.8 million settlement from the Justice Department for the damage done to his reputation. In 2008, attention shifted to Bruce Ivins, a microbiologist at the U.S. Army Medical Research Institute of Infectious Diseases at Fort Detrick, Maryland. He died by suicide in July 2008 as prosecutors were preparing to indict him. The FBI officially closed the case blaming Ivins, citing genetic analysis linking the anthrax strain to his laboratory. However, several of Ivins's colleagues, his former therapist's initial statements, and independent scientists disputed aspects of the case against him. The case was formally closed in 2010 with Ivins named as the sole perpetrator. The anthrax attacks accelerated the dramatic expansion of biodefense spending in the United States and fundamentally changed how biological threats are assessed in the post-9/11 era. Whether Ivins truly acted alone — or at all — remains contested, and the case is widely regarded as one of the most controversial unsolved-or-contested investigations in FBI history.