As NPR counterterrorism correspondent Dina Temple-Raston reported earlier, the FBI has announced that it has closed the investigation into the anthrax attacks that followed Sept. 11:
"Earlier today, representatives of the FBI and Justice Department provided a 92-page investigative summary along with attachments to victims of the attacks, relatives of the victims and appropriate committees of Congress," the Bureau said in a statement.
According to the FBI, the Amerithrax Task Force "was comprised of roughly 25 to 30 full-time investigators from the FBI, U.S. Postal Inspection Service and other law enforcement agencies, as well as federal prosecutors from the District of Columbia and the Justice Department's Counterterrorism Section."
Their investigative efforts involved more than 10,000 witness interviews on six different continents, the execution of 80 searches and the recovery of more than 6,000 items of potential evidence during the course of the investigation. The case involved the issuance of more than 5,750 grand jury subpoenas and the collection of 5,730 environmental samples from 60 site locations.
Information about the investigation, made available under the Freedom of Information Act is available here.