Quality sample collection, handling, and preservation for an effective microbial forensics program

Science can be part of an effective investigative response to a bioterrorism event or a biocrime by providing capabilities to analyze biological and associated signatures in collected evidence. Microbial forensics, a discipline comprised of several scientific fields, is dedicated to the analysis of evidence from such criminal acts to help determine the responsible party and to exonerate the innocent (6). A partnership among a number of government agencies, academia, and the private sector has been formed to better respond to and deter potential perpetrators of bioterrorism or biocrimes. This partnership leverages our national scientific and analytical capabilities to support activities of law enforcement agencies. The Department of Homeland Security (DHS), whose mission is, in part, to respond to and to prevent acts of terrorism against the United States, has established the National Bioforensics Analysis Center (NBFAC) (4,6). The NBFAC, in partnership with the Federal Bureau of Investigation (FBI), (i) provides a state-of-the-art central laboratory for analysis of microbial forensic evidence and (ii) serves as a nexus for integrating the national resources to increase the effectiveness of law enforcement in obtaining the highest level of attribution possible in criminal cases where the weapon is a biological agent. One approach used by the NBFAC to establish a sound foundation, to foster communication, and to facilitate integration across government and other agencies is to promote independent meetings, which address specific needs and provide a forum for input from the broader scientific community, on the best scientific practices in microbial forensics (5). As part of this ongoing effort, a series of meetings sponsored by DHS were held at the Banbury Center of the Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, to address specific issues for the enhancement of microbial forensic capability. One such meeting, held on 16 to 19 October 2005, focused on the collection, handling, and storage of samples. These issues had been identified at previous meetings (5, 6) as some of the most critical issues confronting a crime scene investigation and subsequent analysis of evidence. The participants represented diverse scientific entities within academia, the private sector, the national laboratories, and several federal agencies (Central Intelligence Agency, Centers for Disease Control and Prevention, DHS, FBI, Food and Drug Administration, and U.S. Department of Agriculture), some of which have been involved in evidence collection for purposes related to forensics, public health, or plant and animal health. The collection and preservation of microbial forensic evidence are paramount to efficient and successful investigation and attribution. If evidence (when available) is not collected, degrades, or is contaminated during collection, handling, transport, or storage, the downstream characterization and attribution analyses may be compromised. Retrieving sufficient quantities and maintaining the integrity of the evidence increase the chances of being able to characterize the material to obtain the highest level of attribution possible. This paper presents issues related to the practices of sample collection, handling, transportation, and storage and includes recommendations for future directions for the field of microbial forensics and people participating in it. The recommendations apply to the NBFAC, as well as to other facilities and practitioners.