Microbial Forensics: Detection and Characterization in the Twenty-first Century

The use of a biological agent during the commission of a crime or as weapon of terrorism or war is criminalized under national and international law. Like their counterparts in the chemical and physical sciences, biologists have begun to develop the means to investigate the malicious use of pathogens and toxins, a process that entails the detection and characterization of the means of delivery or dispersal, characterization of the agent, and, eventually, attribution of the attack to an individual, organization, or state actor. Each of these investigative steps can be approached first by traditional forensic biological approaches. We limit our discussion to microbial forensics, leaving attribution to other venues. The last decade has seen great progress in molecular forensic capability, and we explore recent and/or novel molecular biological tools that allow the analysis of evidentiary samples. We will argue that DNA is central to the analysis of microbial weapons, as increased access to synthetic biological methodology in the context of digitalization of biomaterials paves the way for the potential construction of bioagents for malicious use. DNA sequencing and analysis permits some prediction of the methods used to synthesize and manipulate DNA as well as the means to detect engineered genetic elements. Other issues of high relevance include approaches to international data sharing, sample and reference collection, pertinent disease surveillance mechanisms and statistical methods. We conclude with a discussion of gaps and challenges in the field.