In 1334 an epidemic struck the northeastern Chinese province of Hopei. This "Black Death" claimed up to 90% of the population, nearly five million people. The epidemic eventually reached and decimated Tartar forces that had been attacking Kaffa, a Genoese colony on the Crimean Peninsula. In 1347, the departing Tartars catapulted plague-infested bodies into Kaffa. The Genoese quickly dumped these bodies into the sea, however it was too late. Four ships escaped back to Italy carrying the plague that in just two years killed one-third of the European population. Today we have antibiotics to overcome the plague, however, this early example of bioterrorism stands as a reminder of our vulnerabilities. This point was reiterated after the attacks of September 11, 2001 revealed our vulnerability to terrorism in general. Shortly thereafter, anthrax in letters delivered by the U.S. Postal Service caused five deaths and thirteen confirmed additional infections, bringing the specific threat of bioterrorism into our consciousness. (See Jernigan JA et. al. (2001) for a detailed description of the first 10 cases.) These attacks have motivated an increase in bioterrorism-related research, and this evolving research area is creating new challenges, responsibilities, and opportunities for statisticians. Bioterrorism refers to the intentional release of organisms that can cause sickness or death. The Centers for Disease Control (CDC) classifies organisms into three categories based on the ease of dissemination or transmission, potential for major public health impact (high mortality), potential for public panic and social disruption, and requirements for public health preparedness. Category A agents (the most dangerous) include anthrax, smallpox, plague, botulism, tularemia, and viral hemorrhagic fever viruses such as Ebola. Research on many of these organisms require "biosafety level 4" (the highest level of containment) facilities. We focus on anthrax; the agent used in the well-publicized recent bioterrorism attacks.