2001 Anthrax Attacks

The 2001 anthrax attacks in the United States, also known as Amerithrax from its Federal Bureau of Investigation (FBI) case name, occurred over the course of several weeks beginning on Tuesday, September 18, 2001, one week after the September 11 attacks. Letters containing anthrax spores were mailed to several news media offices and two Democratic U.S. Senators, killing five people and infecting 17 others. According to the FBI, the ensuing investigation became "one of the largest and most complex in the history of law enforcement".

A major focus in the early years of the investigation was a bio-weapons expert named Steven Hatfill, who was eventually exonerated. Another suspect, Bruce Edwards Ivins, became a focus of investigation around April 4, 2005. Ivins was a scientist who worked at the government's biodefense labs at Fort Detrick in Frederick, Maryland. On April 11, 2007, Ivins was put under periodic surveillance and an FBI document stated that "Bruce Edwards Ivins is an extremely sensitive suspect in the 2001 anthrax attacks." On July 27, 2008, Ivins took an intentional overdose of acetaminophen and died two days later in a hospital.

On August 6, 2008, despite having no direct evidence of his involvement, federal prosecutors declared Ivins to be the sole culprit of the crime. Two days later, Senator Charles Grassley and Rep. Rush Holt called for hearings into the DOJ and FBI's handling of the investigation. On February 19, 2010, the FBI formally closed its investigation.

A review of the scientific methods used in the investigation at the National Academy of Sciences, published in February 2011, cast doubt on the U.S. government's conclusion that Ivins was the perpetrator. The review report said that, although the type of anthrax used in the letters was correctly identified as the Ames strain of the bacterium, there was insufficient scientific evidence for the FBI's assertion that it originated from Ivins' laboratory. The FBI responded by pointing out that the review panel asserted that it would not be possible to reach a definite conclusion based on science alone, and said that a combination of factors led the FBI to conclude that Ivins had been the perpetrator. Some information about the case related to Ivins' mental problems is still "under seal". Lawsuits filed by the widow of victim Bob Stevens were settled by the government for $2.5 million with no admission of liability. According to a statement in the settlement agreement, the settlement was reached solely for the purpose of "avoiding the expenses and risks of further litigations."