Forensic microbiologists have several methods from which to choose. The choice of methodology depends partly on the turnaround time. In potential bioterrorist attacks, rapid and accurate identification of the agent involved is necessary to minimize morbidity and mortality and to prevent panic. In this case, DNA microarrays, or biochips, are popular choices because they can accurately and rapidly identify numerous agents at once. Microarrays contain many different DNA sequences on their surfaces that can bind complementary sequences in test samples. Specificity is determined by the DNA sequences unique to suspected agents of bioterrorism or biocrimes. In such cases, body fluids and environmental samples are treated as physical evidence, and phylogenetic studies of bacteria and viruses are performed and admitted into evidence by a judge.