Responding to a bioterrorism attack presents law enforcement with unique challenges, one of which is determining the perpetrator of the crime. The discipline of microbial forensics has been established to provide an infrastructure for analyzing forensic evidence for attribution and, it is hoped, to serve as a deterrent. The field of microbial forensics did not have to be developed de novo. The foundations for this field were developed from the epidemiologic investigations of emerging and recurring infectious diseases. These two disciplines share a common ground. Ascertaining the identity and physical properties of a deliberately released biologic agent is paramount, in responding to public health and security threats and in identifying the source of the agent. There are still numerous issues relating to bioterrorism preparedness and response that previously have not been considered by public health practitioners and law enforcement officials . Training courses to strengthen the joint effectiveness of public health and law enforcement investigations and ultimately the collection of evidence for microbial forensics are currently being offered [16,86]. To go beyond public health needs and obtain the deepest level of attribution possible or to determine the processes used to develop the biological weapon, there are many tools available to assist the microbial forensic scientist in characterizing evidence. These include biologic, chemical, and physical methods. The field of microbial forensics will continue to mature and likely will focus on the development of faster analytical tools with increased sensitivity of detection, rigorous validation of methods, and development of interpretation guidelines for conveying the significance of an analytical result.