The four faces of microbial forensics.

The emerging field of microbial forensics played a major role in the investigation of the 2001 anthrax mailings and has been closely associated with the process of attribution, or identifying the perpetrator of a biological attack for purposes of criminal prosecution or military retaliation. Nevertheless, microbial forensics has other potential applications in intelligence, nonproliferation, and verification. This article describes the relevance of microbial forensics for a variety of law enforcement and national security missions, examines the obstacles to its broader use, and concludes with some policy recommendations.