Investigation
Authorities traveled to six continents, interviewed over nine thousand people, conducted 67 searches and issued over 6,000 subpoenas. "Hundreds of FBI personnel worked the case at the outset, struggling to discern whether the Sept. 11 al-Qaida attacks and the anthrax murders were connected before eventually concluding that they were not." In September 2006, there were still 17 FBI agents and 10 postal inspectors assigned to the case, including FBI Special Agent C. Frank Figliuzzi who was the on-scene commander of the evidence recovery efforts.
Read more about this topic: 2001 Anthrax Attacks