Microbial Foren

The Four Faces of Microbial Forensics

Jonathan B. Tucker and Gregory D. Koblentz

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 intel-

ligence, 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.

Microbial forensics involves the use of advancedgenetic, chemical, and physical techniques to char- acterize a pathogen or toxin used in a biological attack. Bioforensics is a more inclusive term that covers, in addi- tion to microbial forensics, a variety of other biological forensic techniques, such as human DNA fingerprinting and standard serological analyses (eg, ABO blood typing). Because of the key role that microbial forensics played in the investigation of the 2001 anthrax mailings, this emerging discipline has been linked primarily to the process of ‘‘attribution,’’ or identifying the country, group, or in- dividual responsible for the use of a biological weapon in order to pursue legal prosecution or military retaliation. Nevertheless, microbial forensics has potential applications in other areas of national security, including the investi- gation of alleged biological weapons use by nation-states or terrorist organizations; the assessment of biological weapons capabilities possessed by adversaries; the moni- toring of nonproliferation agreements, such as the United Nations (UN) Security Council resolution mandating the elimination of Iraq’s biological weapons program after the 1991 Persian Gulf War; and the verification of the Biological Weapons Convention (BWC), which currently has no formal compliance measures.

The 4 communities with an interest in microbial forensics—law enforcement, intelligence, nonproliferation, and verification—each have specialized needs dictated by the conditions under which they operate and the demands of their respective missions. As a result, although the ap- plications of microbial forensics involve the same basic tools and techniques and generally meet the same standards of scientific validity, the ways the tools are used differ in several important respects.

First, whether the operating environment is cooperative (as is generally true of law enforcement) or noncooperative (as is usually the case with intelligence collection) will in- fluence the sampling strategy employed.

Second, microbial forensics for law enforcement is almost always based on an actual event (a biocrime or bioterrorism incident), whereas intelligence agencies may use forensic evidence to support predictive threat assess- ments with varying levels of confidence.

Third, the law enforcement, intelligence, nonprolifera- tion, and verification communities have different criteria and thresholds for judging the probative value of forensic evidence and employing it in the decision-making process. For example, the forensic analyses used in law enforcement must meet certain scientific standards to be admitted as

Jonathan B. Tucker, PhD, is a Senior Fellow at the James Martin Center for Nonproliferation Studies, Washington, DC. Gregory D. Koblentz, PhD, is an Assistant Professor and Deputy Director of the Biodefense Program, Department of Public and International Affairs, George Mason University, Fairfax, Virginia.

Biosecurity and Bioterrorism: Biodefense Strategy, Practice, and Science Volume 7, Number 4, 2009 ª Mary Ann Liebert, Inc. DOI: 10.1089=bsp.2009.0043

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evidence in a court of law and are then subject to a rigorous process of cross-examination. In contrast, the microbial forensic evidence used to support intelligence assessments (although it may be of equivalent scientific quality) does not receive the same degree of external review.

Finally, the extent to which the analytical results can be made public or shared with other countries depends on the source of the forensic evidence and the purpose for which it is being used. Whereas many forensic techniques used in law enforcement are published to enhance their credibility with judges and juries, certain techniques used by the intel- ligence community are classified to protect sensitive col- lection methods.

The 4 faces of microbial forensics are not mutually ex- clusive, however, and information collected for one purpose may prove useful for others. For example, microbial forensic analyses performed to support a biological weapons threat assessment could later be brought to bear during the attribution investigation following a biological attack. Indeed, the intelligence community is charged with con- ducting both types of missions.1 Similarly, data about a nation’s biological weapons program obtained for non- proliferation or verification purposes could contribute to threat assessment and attribution. This article describes the 4 applications of microbial forensics, discusses the need for an integrated research strategy, and concludes with rec- ommendations for the future development of the field.

Microbial Forensics and Attribution

Biological weapons agents are well suited for anonymous attacks because they can be delivered covertly and have delayed effects. They may also cause outbreaks that are difficult to distinguish from natural events, making them hard to attribute and hence to deter. The process of bio- logical attribution can be divided into 3 parts: (1) identi- fying the infectious agent and strain responsible for an unusual outbreak of disease; (2) characterizing the outbreak as natural or deliberate in origin; and (3) if the event is judged intentional, determining the state, group, or indi- vidual responsible.2 Microbial forensic analysis of the ge- netic, chemical, and physical characteristics of the pathogen or toxin used in an attack can help investigators to include or exclude a suspect, although sound attribution judg- ments can be made only in conjunction with other types of evidence.

Even before the anthrax letters investigation, microbial forensics had been used to attribute the source of alleged biological attacks and suspicious outbreaks of disease. In the early 1980s, the U.S. and other countries relied heavily on sampling and analysis to investigate allegations that the Soviet Union and its allies had used trichothecene myco- toxins (‘‘yellow rain’’) as a weapon in Cambodia, Laos, and Afghanistan.3 Nevertheless, significant shortcomings in sample collection and chain of custody, as well as the ru-

dimentary state of mycotoxin analysis at the time, cast doubt on the validity of the forensic evidence.4 Subsequent advances in molecular epidemiology—the use of ge- netic sequence information to track the transmission of pathogens—provided useful tools for microbial forensic investigation. In 1998, for example, a phylogenetic analysis of HIV strains helped to convict a doctor of injecting his girlfriend with a sample of the virus obtained from an in- fected patient.5

The revolution in molecular biology, including the ca- pability for whole-genome sequencing, led to the develop- ment of new techniques for identifying microbial strains and substrains on the basis of subtle variations in their DNA sequence. For example, a powerful method of genetic analysis called ‘‘multiple locus variable-number tandem repeat analysis’’ ( MLVA) enabled scientists to resolve a long-standing mystery concerning the bioterrorism activi- ties of the Japanese Aum Shinrikyo cult. In June 1993, cult members grew a liquid suspension of spores of Bacillus anthracis (the bacterium that causes anthrax) and sprayed it as an aerosol cloud from the roof of a building in Tokyo, yet the attack caused no known casualties. MLVA analysis of the spores, cultured from the release site, showed that the cult had mistakenly grown and released the harmless Sterne strain of B. anthracis, which is widely used as a veterinary vaccine.6 In another incident in 2002, a husband and wife from New Mexico traveled to New York City and became ill with a serious infection that was later diagnosed as bu- bonic plague. MLVA analysis of the strain of plague bac- teria (Yersinia pestis) isolated from the 2 patients made it possible to rule out bioterrorism as a possible cause of the outbreak by tracing the source to an endemic focus near the couple’s home in northern New Mexico.7

To date, the most high-profile application of microbial forensics to the attribution of a biological attack was the 7-year ‘‘Amerithrax’’ investigation led by the Federal Bureau of Investigation (FBI) and the U.S. Postal Inspection Ser- vice. Initial genetic analysis of the B. anthracis spores mailed in autumn 2001 revealed that they belonged to the Ames strain, but available techniques could not determine the source of the bacteria. When the spores were cultured on nutrient agar, a small percentage contained mutations that caused them to form atypical colonies, called morphotypes, that differed in shape and color from the norm. The FBI developed genetic assays for 4 of these mutations and used them to screen a repository of 1,070 samples of B. anthracis Ames collected from 19 domestic and foreign labs. Only 8 samples tested positive for all 4 mutations and were traced back to the same source: a flask labeled RMR-1029 at the U.S. Army Medical Research Institute of Infectious Dis- eases in Maryland. Further investigation with standard police methods narrowed the pool of suspects down to Bruce E. Ivins, a veteran anthrax researcher at the Army laboratory. Tragically, Ivins committed suicide before he could be put on trial, leaving unanswered questions about the strength of the evidence against him, which has not

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been fully revealed or subjected to cross-examination. In September 2008, the FBI requested that the U.S. National Academy of Sciences review the scientific aspects of the Amerithrax investigation to determine whether the micro- bial forensic techniques used by the bureau were reliable and sufficiently validated, and whether the FBI reached the appropriate scientific conclusions from its use of these techniques.

Another potential application of microbial forensics for attribution purposes is to support international investiga- tions of alleged biological weapons use. The International Criminal Police Organization (Interpol) has launched an initiative to build the capacity of law enforcement agencies around the world to investigate bioterrorism incidents, including some sharing of microbial forensic techniques. In addition, during the 1980s, the UN General Assembly adopted a series of resolutions empowering any member state to report a suspected incident of chemical, biological, or toxin weapons use and to request the Secretary-General to dispatch an international group of experts to conduct an objective field investigation. Between 1980 and 1992, the Secretary-General launched a dozen such investigations, all involving the alleged use of chemical or toxin weapons.8

Although the most recent UN field investigation took place in 1992, the mechanism remains in effect and can draw on more than 200 experts and 20 analytical laboratories nominated by 41 member states.* The UN Office of Dis- armament Affairs (ODA) is charged with maintaining the lists of experts and laboratories, training and exercising the experts, developing standard operating procedures for sampling and analysis, and providing logistical support to teams conducting field investigations. Samples taken as part of an investigation would be split into 4 aliquots, with 1 portion going to the host country and the others to 3 independent laboratories for analysis (authors’ interview with a UN official, August 4, 2009).

In the event of a biological attack overseas, the U.S. intelligence community would conduct its own investiga- tion. (The FBI would lead the effort if one or more U.S. citizens were targeted.) Because much of the microbial fo- rensic information would be collected with sensitive intel- ligence methods or for possible use in a criminal trial, it might not be releasable to other countries. Thus, an impor- tant advantage of the UN Secretary-General’s mechanism is that the findings would be unclassified and could be widely shared. A UN-sponsored investigation would also have greater international credibility, providing a stronger basis for mobilizing multilateral political, economic, and even military sanctions against the attacker. Nevertheless, the microbial forensic capabilities of the Secretary-General’s

investigative mechanism remain unproven, and ODA does not have sufficient resources to develop new or improved assays, validate sampling and analysis protocols, or test the proficiency of reference laboratories.

In contrast, the Organization for the Prohibition of Chemical Weapons (OPCW), the international body in The Hague that implements the Chemical Weapons Conven- tion (CWC), regularly conducts ‘‘round-robin’’ proficiency exercises with OPCW-certified laboratories to test their ability to identify unknown chemical warfare agents cor- rectly. Microbial forensics requires a similar international capability. Because sampling and analysis would play a key role in any UN field investigation of alleged biological weapons use, the U.S. should make some of its expertise in this field available to the United Nations. In addition, classified information that is important for attribution or exclusion, such as data on genetically engineered pathogens or weaponization techniques, might be shared with UN investigation teams on a case-by-case basis.

Microbial Forensics and Threat

Assessment

The U.S. intelligence community has a long-standing in- terest in the use of microbial forensics to characterize the threat posed by foreign biological weapons programs, and it has developed a number of techniques and processes to collect, transport, analyze, and interpret samples that have made important contributions to the field. For reasons of secrecy, however, the intelligence community’s pioneering role in microbial forensics technology has not been widely recognized. During the Amerithrax investigation, for ex- ample, the FBI turned to the CIA and other intelligence agencies for technical assistance (authors’ interview with Jenifer Smith, principal, BioForensic Consulting LLC, Washington, DC, October 29, 2009).

Microbial forensics can make a key contribution to biological threat assessment. Because most field detectors, diagnostic kits, and medical countermeasures are agent- specific, it is important to know if an adversary is devel- oping exotic, antibiotic-resistant, or genetically engineered pathogens. Analyzing the physical characteristics and che- mical composition of a biological warfare agent obtained from a foreign source may also reveal how and where it was produced and the extent to which it has been ‘‘weapo- nized,’’ including the use of specialized processing tech- niques and chemical additives to enhance its effectiveness. In addition to the value of this information for threat as- sessment, it may be useful for consequence management and the conduct of military operations against an adver- sary’s biological weapons production and storage facilities.

Applying microbial forensics to threat assessment faces several hurdles, mainly related to the conditions under which samples are collected. Whereas criminal investi- gators and international inspectors can operate openly,

*Ever since the entry into force in 1997 of the Chemical Weapons Convention (CWC), which has provisions for investi- gating chemical or toxin weapons use, the focus of the Secretary- General’s mechanism has shifted to biological weapons.

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intelligence operatives must collect samples covertly. They may lack direct access to a biological weapons facility, forcing them to rely on stand-off air sampling or the col- lection of environmental samples; or they may have access to the facility for only a short amount of time, precluding the use of comprehensive sampling techniques. Such con- straints may lead to misleading results, sometimes with negative consequences. In 1998, for example, the U.S. apparently misidentified the Al Shifa pharmaceutical plant in Khartoum, Sudan, as a chemical weapons production facility based on the analysis of a single soil sample collected by a covert operative who did not have direct access to the facility. The Al Shifa plant was subsequently destroyed by a U.S. cruise-missile strike.9,10

The number and quality of samples collected by covert means may also be problematic because of the natural presence in the environment of certain pathogens of bio- logical weapons concern (such as B. anthracis), which may be hard to distinguish from those associated with a local production facility; contaminants in the sample matrix (soil or wastewater) that interfere with analytical techniques or cause molecular signatures to become unstable; and sub- optimal storage and preservation of samples containing viable organisms. During shipment from the collection site to the analytical laboratory, samples may change hands several times, making it difficult to establish a clear chain of custody. Finally, the need to protect undercover operatives and clandestine collection capabilities may preclude the sharing of analytical results with other countries or interna- tional organizations. The intelligence community is aware of these technical problems and has implemented plans to reduce or mitigate them to the extent possible.

Microbial forensics can help to corroborate or refute biological threat information obtained from other sources. For example, the U.S. intelligence community used micro- bial forensic techniques to assess the former Soviet Union’s development of B. anthracis as a biological weapon. In 1998, a group of molecular biologists conducted a retrospective analysis of tissue samples from 11 victims who died during the 1979 anthrax outbreak in the Soviet city of Sverdlovsk (now Ekaterinburg, Russia). Although the Soviet authori- ties claimed at the time that the outbreak had resulted from the consumption of contaminated meat, a later investiga- tion uncovered extensive epidemiological and pathological evidence indicating that the victims had died of inhalational anthrax caused by the accidental release of aerosolized B. anthracis spores from a nearby military microbiology facility.11

To characterize the strain of B. anthracis involved in the Sverdlovsk outbreak, it was necessary to develop new methods for extracting DNA from preserved samples of the victims’ lung tissue, which had been fixed with formalin and embedded in paraffin. After obtaining the cellular DNA, the investigators used a technique called the poly- merase chain reaction (PCR) to identify genetic sequences specific to B. anthracis. This analysis determined that the

entire set of bacterial genes required for virulence was present in the victims’ lung tissue, including the 2 plasmids (loops of extra-chromosomal DNA) that encode the sub- units of the anthrax toxin and the protective capsule of the bacterium. It was also determined that a mixture of B. anthracis strains was present, providing clear evidence that the Sverdlovsk outbreak had not been natural in origin.12

In the mid-1990s, U.S. scientists conducted additional analyses of the B. anthracis preparation from Sverdlovsk to better understand its virulence, hardiness, and whether or not it had been genetically modified.13

Despite such successes, however, the role of microbial forensics in biological threat assessment has not always been given the priority it deserves. Prior to the 2003 Iraq War, for example, the U.S. intelligence community based its estimate of Iraq’s biological weapons capabilities almost entirely on human intelligence (HUMINT) sources such as the Iraqi engineer code-named ‘‘Curveball,’’ who later proved to be a fabricator.14 Had senior U.S. policymakers demanded that the human intelligence reporting on Iraq’s alleged biological weapons capabilities be corroborated with measurement and signature intelligence ( MASINT), including microbial forensic data, the intelligence agencies might not have made the serious errors in their assessments (authors’ interview with Jenifer Smith, October 29, 2009).

Microbial Forensics

and Nonproliferation

Microbial forensics also has utility for monitoring the proliferation of biological weapons and supporting non- proliferation measures, such as export and border controls. From 1991 to 1998, the investigation of the Iraqi biological weapons program by the UN Special Commission on Iraq (UNSCOM) provided the first opportunity to field-test a number of sampling and analysis techniques. These efforts were hindered initially by the rudimentary state of micro- bial forensics technology at the time. Aware that inspectors might take environmental samples, Iraqi officials sought to eliminate the telltale signatures of biological warfare agents by decontaminating munitions and production equipment with bleach and potassium permanganate.15 As a result, despite extensive sampling in the early 1990s at suspect sites such as Salman Pak and Al Hakam, UNSCOM was unable to obtain direct evidence of past Iraqi production of biolog- ical warfare agents. Pointing to these negative results, Iraq tried unsuccessfully to persuade the UN Security Council that the biological weapons file should be closed.16,17

By the mid-1990s, however, microbial forensic tech- niques had improved significantly. In 1996, UNSCOM was able to obtain the first direct evidence of Iraq’s past production of biological warfare agents by using a new sampling methodology and PCR analysis to detect traces of DNA from B. anthracis on items of production equipment that had earlier tested negative. In addition, sampling and

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analysis of Iraqi missile warheads recovered from a disposal site at Al Nibai found traces of B. anthracis DNA on at least 7 of the warheads, 2 more than Iraq claimed had been filled with the agent. In response to this finding, Iraq filed a revised ‘‘full, final, and complete declaration’’ stating that it had filled 16 warheads with B. anthracis and 5 with botu- linum toxin, rather than the other way around. The ease with which the Iraqi regime amended its declaration to accommodate the new facts uncovered by UNSCOM further damaged Baghdad’s credibility.18

UNSCOM’s successor, the United Nations Monitoring, Verification and Inspection Commission (UNMOVIC), conducted inspections in Iraq from November 2002 to March 2003. This agency made use of improved sampling and analysis protocols that resolved some long-standing controversies surrounding the Iraqi biological weapons program. UNMOVIC set up a molecular biology labora- tory in Baghdad that screened samples for biological warfare agents with a variety of analytical techniques, such as rapid PCR; for more sophisticated analyses, the Commission relied on a network of 6 international reference laborato- ries.19 During its 4 months of inspections in Iraq, UN- MOVIC conducted 354 tests on 101 biological samples from 17 suspect sites.20 None of these analyses detected any prohibited biological warfare agents.

In an effort to verify Iraq’s claim that it had unilaterally destroyed all of its biological munitions shortly after the 1991 Persian Gulf War, UNMOVIC tested the liquid contents of 2 R-400 bombs that Iraq excavated in February 2003. Initial screening tests for biological warfare agents at the UN laboratory in Baghdad were negative because the lab did not have the capability to concentrate trace levels of DNA or to remove the decontaminating chemicals that Iraq had used. The samples were then sent to an interna- tional reference lab, which determined that both R-400 bombs contained DNA from a virulent strain of B. anthracis identical to the one that Iraq had admitted weaponizing.21

Thus, microbial forensic analysis in Iraq was capable of extracting useful information from biological material that had been treated with chemical decontaminants and then buried for more than 12 years. This remarkable achieve- ment demonstrates the power of PCR techniques to detect and identify minute quantities of DNA from nonviable organisms. Although most living biological warfare agents are fragile and survive only a short time in the environment (with the notable exception of B. anthracis spores), this case demonstrates the durability of microbial DNA and its utility for forensic analysis.

An important lesson of the UN weapons inspections in Iraq was that evidence obtained by sampling and analysis is more credible than that derived from interviews or documents, because the forensic data are objective, scien- tifically based, and not easily refuted. Even so, sampling must be conducted carefully to minimize the risk of false- negative or inconclusive findings (authors’ interview with a UN official, August 4, 2009). As in the case of law

enforcement, weapons inspectors must integrate microbial forensic evidence with information from other sources, such as a review of production ledgers and import-export records. Moreover, despite ongoing improvements in the sensitivity and specificity of microbial forensic tech- niques, future biological weapons proliferators may devise more sophisticated means of decontamination to pre- vent the collection of telltale evidence by sampling and analysis.

Microbial Forensics and Verification

Another potential application of microbial forensics is for verification of the Biological Weapons Convention, which lacks formal mechanisms to monitor compliance. In Sep- tember 1991, the Third Review Conference of the BWC established an Ad Hoc Group of Governmental Experts (known as ‘‘VEREX’’) to identify and examine potential verification measures from a scientific and technical standpoint. The VEREX group assessed 21 different veri- fication techniques and concluded that some combinations of measures would contribute to monitoring compliance with the treaty.22

One of the measures examined by VEREX was ‘‘sam- pling and identification.’’ The experts found that off-site sampling (eg, from the waste stream of a biotech plant) was of limited value because, if a biological agent was detected, the source would be difficult to determine. In contrast, on- site sampling ‘‘could provide key information to resolve certain ambiguities about compliance because of the pos- sibility of identifying the nature of an agent . . . [and] of obtaining an independent confirmation of analytical results in the event that findings are disputed.’’22(p14) A negative result, however, would not necessarily rule out a BWC violation. The VEREX group noted further that the value of on-site sampling could be enhanced by having a prior indication of which biological warfare agents to look for, by collecting multiple samples at the same site, and by em- ploying more than one analytical technique.22 Beginning in 1995, BWC member states negotiated a legally binding protocol designed to increase confidence in compliance by augmenting the Convention with a number of on-site verification measures, including sampling and analysis, but the talks collapsed after the U.S. rejected the draft protocol in 2001.

At least in principle, however, techniques such as PCR and MLVA can be powerful tools for treaty monitoring and verification. To achieve this potential, sampling and anal- ysis methods must provide a high degree of sensitivity and specificity, and they must also protect confidential propri- etary information (CPI) unrelated to biological weapons. Pharmaceutical and biotechnology companies are particu- larly concerned about the risk of industrial espionage, be- cause their competitive edge may depend on the use of genetically engineered production microorganisms that

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could be removed surreptitiously from a plant and analyzed to reveal valuable trade secrets.

To a large extent, the Chemical Weapons Convention and its international implementing body, the OPCW, have addressed the challenge of safeguarding proprietary in- formation during sampling and analysis. The OPCW in- spectorate, which visits chemical plants in CWC member states throughout the world, employs a portable analytical instrument called a gas chromatograph-mass spectrometer. This device is equipped with ‘‘blinded’’ software that tells the operator which treaty-controlled chemicals are present in the sample but does not disclose the identity of other, proprietary chemicals. Inspectors are also required to erase the data from the instrument’s electronic memory before leaving an inspected facility. Presumably, similar tech- niques for protecting confidential proprietary information could be developed for sampling and analysis during on-site inspections of dual-use biological facilities. The targeted identification of specific microbial pathogens and toxins (or related genes) of biological weapons concern could be achieved through the use of highly specific antibody as- says, PCR amplification, and DNA probes. In this way, microbial forensics could be applied for verification pur- poses while limiting the intrusiveness of the inspection process.

Microbial Forensics Research

and Development

To date, the attribution and threat-assessment missions have driven the development of microbial forensic tech- nologies; the nonproliferation and verification missions have piggybacked somewhat on these advances but have remained underdeveloped. One reason is that a fragmented organizational structure in the U.S. government has ham- pered efforts to enhance microbial forensic capabilities across the full range of potential national security applica- tions. Each of the agencies with an interest in the field has tended to pursue its own parochial interests without coor- dinating the development of technologies and protocols that would benefit them all.

In 2004, for example, the Department of Homeland Security (DHS) established the National Bioforensic Ana- lysis Center (NBFAC) at Fort Detrick, Maryland, which was designated the ‘‘lead Federal facility to conduct and facilitate the technical forensic analysis and interpretation of materials following a biological attack.’’23 Despite its nominal role as a national resource, however, NBFAC’s primary customer is the FBI, and it is just one of many programs competing for funds within the DHS Science and Technology Directorate. Moreover, the CIA and other members of the intelligence community have maintained independent microbial forensic capabilities, ostensibly be- cause their mission differs from that of NBFAC. While some degree of redundancy in U.S. microbial forensic

capabilities is useful for providing surge capacity in the event of a large-scale biological attack (or multiple smaller attacks), there is a clear need for better interagency coor- dination.

The U.S. government has made a preliminary effort to coordinate microbial forensic activities, but it remains a work in progress. A Bioforensics Working Group, made up of DHS, the FBI, the intelligence agencies, the U.S. Secret Service, Customs and Border Protection, and the State Department, meets quarterly to identify gaps and leverage investments.24 (Although the State Department has the lead for nonproliferation and arms control, it is not a technical agency and hence does not participate in efforts to develop biological weapons detection technologies, which are concentrated mainly in the Department of Defense and the national laboratories operated by the Department of Energy.) In addition, the FBI’s Scientific Working Group on Forensic Analysis of Chemical, Biological, Radiological, and Nuclear (CBRN) Terrorism includes U.S. scientists from government, academia, and industry, as well as Canadian government representatives, but the mandate of this group is limited to developing best prac- tices and quality assurance guidelines, not coordinating research and development (R&D) (authors’ interview with Ben Garrett, Senior Scientist, FBI Laboratory, Washington, DC, May 29, 2009).

Moreover, despite the impressive achievements of mi- crobial forensics in the Amerithrax case, the field still re- quires considerable basic and applied research. According to a 2007 assessment by the U.S. National Counter- proliferation Center, ‘‘microbial forensics is a nascent ca- pability hampered by technical limitations and gaps in our fundamental knowledge about many microbial species. These gaps, combined with a poor understanding of the forensic limitations of research tools, hinder the develop- ment of a robust microbial forensic capability.’’25(p9) In 2009, in an effort to rationalize microbial forensics R&D across the U.S. government, the Office of Science and Technology Policy established a Task Force on Microbial Forensics under the auspices of the National Science and Technology Council. This task force grew out of White House policy guidance on CBRN attribution, issued in 2007, that decoupled the development of laboratory cap- abilities for microbial forensics from the broader process of attribution. Not only does attribution have more opera- tional elements than microbial forensics, but policymakers did not want scientific debates over competing analytical methodologies to overshadow discussions on how to struc- ture attribution decision making.

The Task Force on Microbial Forensics, jointly chaired by the CIA, the FBI, and DHS, coordinated the develop- ment of a National Research and Development Strategy for Microbial Forensics. This document has 3 broad themes: (1) the establishment of a strategic research agenda, (2) the promotion of interagency communication and coordina- tion, and (3) the development of interagency education and

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training programs. Each of these themes includes a delin- eation of agency roles and missions and specific action items.

The Task Force on Microbial Forensics is also develop- ing an implementation plan for the national strategy (au- thors’ interview with Peter Emanuel, Office of Science and Technology Policy, Washington, DC, June 16, 2009). A key component of this plan is the creation of an interagency Microbial Forensics Advisory Board ( MFAB), whose membership, charter, and budget remain to be determined. The advisory board is expected to have 3 main tasks: co- ordinating microbial forensics R&D, ensuring that sam- pling and analysis techniques and protocols are validated, and conducting outreach to the scientific community and policymakers.

When drawing up the research agenda, MFAB should engage all of the agencies involved in developing microbial forensic techniques, as well as those with policy and oper- ational roles in attribution, threat assessment, nonprolifer- ation, and verification. Such a broad membership would enable the advisory board to prepare a comprehensive set of requirements for the R&D community, maximizing the utility of microbial forensic technologies across the spec- trum of national security missions. For example, as NBFAC develops ever more sophisticated analytical capabilities, it will soon outstrip the requirements of the FBI’s law en- forcement mission. Thus, it may be opportune to review NBFAC’s mandate and explore new opportunities for ap- plying advances in microbial forensics to underserved mis- sion areas, such as nonproliferation and treaty verification.

MFAB should also establish a framework for interagency coordination to meet requirements, oversee periodic peer reviews of ongoing research, and conduct capability as- sessments. Regardless of the specific application of micro- bial forensics, it is important to validate techniques and protocols for sample collection, packaging, transportation, analysis, and interpretation. A one-size-fits-all approach is not workable, because each community has its own re- quirements, dictated by its mission and operational envi- ronment. Nonetheless, MFAB could play an important oversight role, ensuring that each agency involved in mi- crobial forensic research, operations, and analysis makes use of validated techniques and protocols.

MFAB could play a useful role in resolving difficulties surrounding NBFAC’s initiative to create a National Strain Repository that contains a comprehensive collection of fo- rensically important pathogens from around the world. The adoption and use of standard reference strains would enable the various agencies involved in microbial forensics to work together as a community to develop and validate assays (authors’ interview with Peter Emanuel, White House Office of Science and Technology Policy, Washington, DC, June 16, 2009). Today, however, the National Strain Re- pository remains a work in progress because the CIA and other intelligence agencies have been reluctant to share mi- crobial cultures obtained through covert operations, while

some academic laboratories and private contractors view exclusive control over certain strains as providing a com- petitive advantage (authors’ interview with White House official, Washington, DC, June 9, 2009). Another problem is that U.S. government agencies use different strain man- agement systems for archiving, tracking, and distribution.

Instead of attempting to build a single repository at NBFAC, a more realistic model would be to create a ‘‘virtual’’ network of existing strain collections based on common quality assurance standards, accreditation criteria, protocols, and infrastructure for sharing cultures and in- formation, and harmonized rules for access and distribution of biological materials. Such a network of strain collections would sidestep the sensitive issue of physical consolidation, reduce the risk that a fire or other catastrophe could destroy the entire repository, and promote the creation of man- agement standards to integrate the dispersed collections. Implementing such an approach, however, will require buy-in from all of the relevant players.

Another important task of MFAB will be outreach to the scientific and policy communities. Television shows such as CSI: Crime Scene Investigation have misled the public into believing that forensic techniques are always rapid, accu- rate, and yield unambiguous results.26 In fact, although microbial forensics played a key role in the Amerithrax investigation, some of the scientific findings remain con- troversial. The advisory board should seek to educate pol- icymakers, members of Congress, and other government stakeholders about the strengths and limitations of micro- bial forensic techniques, the importance of interpreting the data correctly, and the appropriate role of these tools in attribution, threat assessment, nonproliferation, and treaty verification. Given the multidisciplinary nature of micro- bial forensics, it is crucial to engage a wide array of scientists in academia and the private sector. A simple but valuable step would be to develop a lexicon of agreed definitions for key terms in the field.

The U.S. should also foster greater international coop- eration in microbial forensics R&D. Although DHS and DoD have negotiated bilateral agreements with close allies such as Australia, Canada, Germany, and the United Kingdom, the U.S. Select Agent Rules have created ob- stacles to international collaboration because they require partner-countries to have comparable biosecurity regula- tions in place. Furthermore, the U.S. has a long tradition of using scientific evidence (such as human DNA finger- printing) in court, but many other countries rely exclusively on eyewitness testimony and circumstantial evidence. To address these problems, the U.S. should sponsor an inter- national working group of experts in microbial forensics, law enforcement, intelligence, nonproliferation, and veri- fication to facilitate collaboration on R&D projects, ex- change information, share best practices, and conduct joint exercises. The U.S. government should fund the develop- ment of unclassified microbial forensics technologies that can be shared with other countries and multilateral bodies.

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Conclusions

A major shortcoming of U.S. policy on microbial forensics has been the lack of a national strategy designed to enhance the utility of these techniques across the full range of law enforcement and national security missions. While such a strategy should acknowledge the specialized needs of the attribution, threat assessment, nonproliferation, and veri- fication communities, it should also seek to maximize synergies among these different applications. Because the attribution and threat assessment missions have received the bulk of resources to date, the strategy should provide guidance on leveraging existing investments in microbial forensics for new applications in nonproliferation and verification. To support these multiple missions, the strat- egy should provide a roadmap for developing government- wide standards for validating sample collection and analysis methods. Also needed are common approaches and mate- rials for educating analysts and policymakers about the capabilities and limitations of microbial forensics and the importance of how the results are interpreted. Finally, the strategy should establish a framework for pursuing in- ternational cooperation on microbial forensics R&D and the multilateral investigation of biological attacks perpe- trated by states, terrorists, or criminals.

In sum, microbial forensics has the potential to revolu- tionize the fight against the acquisition and use of biological weapons by both state and non-state actors, but only if the full potential of the discipline is leveraged for maximum utility across the full spectrum of law enforcement and national security applications.

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Manuscript received August 20, 2009; accepted for publication November 6, 2009.

Address correspondence to: Gregory D. Koblentz, PhD

Department of Public and International Affairs George Mason University

4400 University Drive MS3F4 Fairfax, VA 22030

E-mail: [email protected]

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