The Spin Doctors

The National Research Council February 2009 report on forensic science was widely perceived as an indictment of laboratories and expert witnesses across the United States. Newspaper and magazine articles, op-ed headlines, television news, and radio talk shows referred to the field as “seriously deficient,” “dismal science,” “in disarray,” even “clueless.” [1, p. 8]. The NRC report concludes that many fields of forensic science are under-researched, under-regulated, and oversold.

Parts of the forensic science establishment have responded with various forms of denial. One ploy is to challenge the thoroughness of the report. For example, on April 29, 2010, I listened to the supervisor of the Arizona Department of Public Safety’s laboratories, Todd Griffith, spin an interesting story about the report. According to Mr. Griffith, the National Academy of Science (NAS) committee correctly endorsed the well validated methods of forensic toxicology and DNA profiling but incorrectly rejected the equally well validated procedures for other forensic disciplines. To prove that the committee did not adequately examine the immense body of research supporting current testimony, Mr. Griffith provided the names of the many journals with articles on forensic science.

In a similar vein, the Scientific Working Group on Friction Ridge Analysis, Study, and Technology (SWGFAST) issued a position paper “respectfully disagee[ing]” with the NRC’s observation that “[w]ith the exception of nuclear DNA analysis, . . . no forensic method has been rigorously shown to have the capacity to consistently, and with a high degree of certainty, demonstrate a connection between evidence and a specific individual or source.” According to this group of fingerprint analysts, “[h]istory, practice, and research have shown that fingerprints can, with a very high degree of certainty, exclude incorrect sources and associate the correct individual to an unknown impression” [2].

To a degree, the NRC committee set itself up for this criticism by the lack of full documentation of many of its conclusions. The report could have contained an analysis (at least in an appendix) of the relevant studies that have been published in quality journals. Other NRC committees (on polygraphs in lie detection, on compositional analysis of bullet lead, and on DNA evidence, to name three) were less conclusory — and hence more convincing — in their assessments of the state of the science.

Still, if one must choose between the NRC’s evaluation and the denials of practicing forensic scientists, there is no contest. Where is the published, rigorous scientific research that shows that latent print examiners can tell that only one individual in the world could be the source of a latent print (as these examiners assert day in and day out in the courtroom)? It does not appear among the seven references cited by SWGFAST. Where is the proof that marks on bullets permit them to be matched to the barrel of a single gun? Mr. Griffith’s response was a study that showed that examiners could correctly match ten bullets to ten barrels. Such research is encouraging. It demonstrates that firearms examiners are not just guessing (although no one ever said they were). But it does not begin to address firearm examiners’ claims of discernible uniqueness [3, 4].

Responses like those of the Arizona DPS and SWGFAST prompted NAS Committee co-chairman and United States Court of Appeals Judge Harry T. Edwards to remark at a conference last week that “no one has meaningfully refuted the Committee’s finding” about individualization [5, p. 3]. Moreover, Judge Edwards replied to the “they did not read our research” complaint by explaining that

The Committee spent an enormous amount of time listening to testimony from and reviewing materials published by numerous experts, including forensic practitioners, heads of public and private laboratories, directors of medical examiner and coroner offices, scientists, scholars, educators, government officials, members of the legal profession, and law enforcement officials. Not only did we examine how the forensic disciplines operate, we also carefully considered any peer-reviewed, scientific research purporting to support the validity and reliability of existing forensic disciplines. Additionally, we invited experts in each discipline to refer us to any pertinent research. Committee members and staff spent countless hours reviewing these materials. And before the Report was released, it was peer-reviewed by outside experts in the fields of science, law, and forensic practice.

[5, p. 2].

To avoid confrontations it cannot win, the forensic science community needs to consider alternative ways to present the findings of fingerprint analysts, toolmark examiners, handwriting analysts, and, yes, even DNA profilers. (Claims of probabilities in the quadrillions and septillions have their own problems.). There is considerable information in the forensic evidence. It is time to present it fairly and with a frank recognition of its possible limitations.


1. David H. Kaye, The Good, the Bad, and the Ugly: The NRC Report on Strengthening Forensic Science in America, 50 Sci. & Justice 8 (2010).

2. SWGFAST, Strengthening Forensic Science in the United States: A Path Forward, 2009, Aug. 3, 2009 (

3. Michael J. Saks & Jonathan J. Koehler, The Individualization Fallacy in Forensic Science Evidence, 61 Vand. L. Rev. 199 (2008).

4. David H. Kaye, Probability, Individualization, and Uniqueness in Forensic Science Evidence: Listening to the Academies, 75 Brook. L. Rev __ (2010, in press).

5. Harry T. Edwards, The National Academy of Sciences Report on Forensic Sciences: What it Means for the Bench and Bar, Address at the Superior Court of the District of Columbia Conference on the Role of the Court in a Developing Age of Science and Technology, Wash. D.C., May 6, 2010 ($FILE/Edwards%2C+The+NAS+Report+on+Forensic+Science.pdf).