by Michael Lynch, Simon A. Cole, Ruth McNally, and Kathleen Jordan. Chicago: University of Chicago Press, 2008. 416pp. Cloth. $37.50. ISBN: 9780226498065.

Reviewed by Marvin Zalman, Department of Criminal Justice, Wayne State University. Email: aa1887 [at]


Josiah Sutton, a black man with a prior juvenile record, was convicted for a 1998 rape in Houston. The victim, who was abducted in her car and raped by two men, identified Sutton and another man days after the rape by their hat styles. A Houston Police Department Crime Laboratory analyst reported that “a mixture of DNA types consistent with J. Sutton, [the victim], and at least one other donor was detected on the vaginal swabs. . . . The DNA type of J. Sutton can be expected to occur in 1 out of 694,000 people among the black population” (p.279). The other man was excluded. With this evidence from the DNA “truth machine,” Sutton was convicted and that should have been the end of the matter. Except that it wasn’t.

As reported by the authors of TRUTH MACHINE, a 2002 television exposé of the Houston crime lab brought in DNA expert William Thompson who excoriated the lab (p.280). He pointed to failings that included routinely neglecting to follow proper scientific procedures, biased interpretation of results, biased statistical estimates against defendants, and even outright misrepresentation of scientific findings.

The error in Sutton’s case was not issued by a pathological liar, like the West Virginia criminalist Fred Zain, who fabricated reports of guilt out of whole cloth. Nor was the identification based on a contaminated sample. Sutton was linked to the crime scene sample by a combination of a limited and early form of DNA testing, an erroneous calculation of the low probability that the sample could have come from another donor, and incompetence in failing to exclude Sutton by the presence of an “anomalous” allele in a vaginal sperm fraction not carried by Sutton or the victim. To a lay person DNA testing is DNA testing. By the end of TRUTH MACHINE, however, a lay reader is well enough informed about continuous technological advances and refinements so as to appreciate that the analytic technique employed was the DQ-alpha polymarker system supplemented by other techniques with a “relatively limited array of possible alleles” (p.281), and not the more advanced STR system (which tests 13 DNA loci) that excluded Sutton’s DNA. As for the inflated probability of a match, the crime lab apparently combined samples from at least three persons (the victim and two rapists) into one profile that increased the likelihood “that a DNA profile taken from a randomly chosen person would match a subset of those markers” (p.281). When Thompson recalculated the probability of a coincidental match, the probability dropped from one in 694,000 to one in eight. [*284]

Michael Lynch, Simon Cole, Ruth McNally, and Kathleen Jordan do not dispute the great discriminatory power of proper DNA testing as a method of identification. But TRUTH MACHINE cautions that the method is not infallible. In cases of random hits on large DNA database searches, the identification cannot be the exclusive basis of guilt without developing the context of the case. Again, Sutton’s case is instructive. The victim first identified each of the perpetrators as weighing about 135 pounds and about 5 feet 7 inches tall. Sutton was over 6 feet tall and weighed 200 pounds. After her initial identification, based on the fact that Sutton and another black man were wearing, respectively, a baseball cap with the bill turned sideways and a skullcap, the police held a showup with the men in the back seat of one police car while the victim sat in another. Sutton may have had the worst defense lawyer in Harris County, which was the leading producer of death sentences in the country. The attorney never won an acquittal for a client and “had the dubious distinction of having sent more of his former clients to death row than any other defense attorney in the United States” (p.280). The attorney did not challenge the work of the Houston crime lab. Ideally, such incompetence should have raised alerts regarding a possible miscarriage of justice. Unfortunately, haphazard work is often the norm in American courts.

On one level, TRUTH MACHINE is a powerful reminder that the highly adversary American system of criminal justice cannot work properly if it is unbalanced. But TRUTH MACHINE is far more. It is a high-octane book for specialized audiences that traces, as the subtitle has it, the “contentious history” of the use of DNA profiling techniques to link biological evidence to criminal suspects. The authors are leading scholars in the small and relatively new discipline of Science and Technology Studies (S&TS), which they describe as “a transdisciplinary field that combines the history, social study, and philosophy of science” (p.2). (Michael Lynch is editor of the journal Social Studies of Science, a leading outlet for S&TS research.)

To describe TRUTH MACHINE as a history of the fifteen years during which DNA profiling passed through a period of legal and scientific testing and controversy to emerge as the gold standard or paradigm of “the truth” in courts, would be like saying that Herman Melville’s MOBY DICK is just a story about a whale boat captain’s obsessive pursuit of a ferocious albino whale resulting in his ship’s destruction. Like MOBY DICK, TRUTH MACHINE is much more, in part because the book includes many asides into recondite byways of DNA and law that provide a wealth of information. The authors do not allow the “asides” to overwhelm the main thrust of the book for several reasons. First, in ten chapters they tell the story in chronological fashion, with each chapter devoted to one of the various complex issues that had to be resolved for DNA profiling to emerge triumphant as the leading identification technique. Second, many but not all of the “asides” are contained in short and excellent appendices, labelled “interludes,” that are strategically located between relevant chapters. [Interludes A through E cover DNA profiling techniques; the law of admissibility; the U.K. national DNA [*285] database; the statistical test for calculating the random match probability for searching DNA databases; and fingerprinting and probability.] Third, the narrative throughout the book is tied thematically to the sociological approach of “controversy studies,” detailed in Chapter 2, which provides a thread that holds the spiraling narrative (perhaps not unlike a strand of DNA) in place. To this end the authors explore, among other questions, how “controversies open and close in a hybrid legal scientific field” (p.xvi).

Because courts and lawyers played a central role in the history of challenges to DNA and its ultimate admissibility, the book could have been a disquisition on the law and science relationship. TRUTH MACHINE, however, provides a fuller exploration that links and cross-references a number of disciplines and methodologies, including law (encompassing the work of appellate and trial courts and “savvy” lawyers), biological science (both university based experimental science and the “administrative” science of institutional laboratories), forensic science (or its less than scientific counterparts that rely on comparisons by experts), and explicit and implied narrative strategies grounded in the sociologically grounded S&TS approach. The chief narrative strategy is a form of “mundane” deconstruction applied by S&TS scholars, resulting in a book that is far different from one I imagine would have been written by legal scholars, biologists, sociologists, or political scientists.

The expertise of the authors of TRUTH MACHINE is amplified by the fact that they have been exploring the so-called DNA wars as they unfolded in England and the United States for fifteen years (p.xiii). The research for the volume included interviews, transcripts of courtroom trials, and laboratory observations. The book includes well-designed graphics that greatly enhance one’s ability to understand concepts and processes. The volume is also based on voluminous previous writings by authors Michael Lynch, Ruth McNally and Kathleen Jordan on molecular biology and such topics as the chain of custody. TRUTH MACHINE draws on the S&TS work of Simon Cole, a leading expert on fingerprinting, in a fascinating exploration of how DNA profiling replaced fingerprinting as the exemplar of physical forensic evidence and threatened its status as admissible evidence. All this results in a complete, nuanced, and thought provoking book.

The first two chapters establish a foundation by asking whether DNA profiling is a “revolution” that augers a paradigm shift in forensic evidence, by grounding the discussion in Kuhn’s (1970) classic study of paradigm shifts in science, by sketching the area of “controversy studies,” and by describing the early legal challenges to the admissibility of DNA profiles around 1990.

Chapters Three through Six explore various facets of the DNA profiling controversy in England and America. Chapter Three not only describes the transfer of DNA techniques from labs concerned with basic science to forensic labs; it provides a basic tutorial in the sociology of laboratory work and an illuminating discussion of the uses and limits of protocols and their use in cross-examination. The latter is supported by [*286] an excerpt from the transcript of a cross-examination of a forensic scientist by the Innocence Project’s Peter Neufeld during the O. J. Simpson trial. Other chapters delve, with great interpretive depth, into the subjects of chains of custody (Chapter Four), how RMPs (random match probabilities) were calculated and presented in evidence in an English case (Chapter Five), and how a major English test case, R. v. ADAMS (1996; 1997), limited the use of Bayesian analysis in other than scientific evidence so as to preserve the ultimate function of the jury (Chapter Six). The latter chapter is entirely respectful of the legal enterprise and offers the caution “that DNA evidence alone is insufficient to convict a suspect unless supported by other evidence” (p.219). This is supported by the mathematical likelihood that data trawling in large DNA databases seeking “cold hits” will produce adventitious matches to innocent persons. Indeed, it happened in one English case (pp.247-48).

The remainder of the book explores the “closure” of the “DNA wars” – the acceptance of DNA by the larger legal and lay world as virtually infallible. A closer examination in Chapter Seven shows that a number of weak points in DNA testing in the early years were corrected by technical, legal and administrative “fixes.” Chapter Eight, “Postclosure,” critically evaluates the acceptance of DNA in popular and political culture as the golden metewand of evidence, and Chapter Nine examines how fingerprinting has been put on the defensive. A most interesting point about this “inversion of credibility” is that LPEs (latent print examiners) were once granted exalted status in the courts when they claimed that there was no error in their conclusions. Now that DNA results are put forward as probabilistic estimates, LPEs have been scrambling to place their work (which seems to me to be a very useful, if not perfect, kind of comparison evidence) in a scientific mold that turns out to look like pseudo-science on close inspection.

The final chapter notes the irony that DNA, having been deemed admissible under the DAUBERT (1993) standard that holds fallibility to be a distinguishing characteristic of science, has come to be taken as irrefutable to such a degree as to generate “positivism about science” and “skepticism about law.” TRUTH MACHINE ends by indirectly offering support for the battered adversary system of justice and its chief engine of ascertaining the truth, cross-examination. “The problem . . . is that ‘DNA’ is not ‘irrefutable,’ and should not be exempted from the fallibility that ‘it’ reveals to be a property of all other forms of evidence” (emphasis in original, p.344).

There are scores or perhaps more of small epistemic reminders throughout TRUTH MACHINE that replicate Magritte’s caption, ceci n’est pas une pipe. For example: “Whereas DNA analysts look at ‘allels’ (or rather, bands, blots, graphic peaks, or other literary proxies for allele size and frequency), LPEs [latent print examiners] look at impressions of ‘friction ridge details’” (p.295). This is relevant to the multidisciplinary focus of the book that is concerned in large measure with the translation of “science” into terms understandable by lawyers and judges, who argue for or against and decide the admissibility of expert evidence. The problem was highlighted by an amusing [*287] exchange in which a judge questioned DNA expert Edward Blake, about the effect of a test to determine a DNA profile. Blake stated that a three-hour testing process on a biological sample would result in “visualizing the consequences” by “running a test gel” on some of the fluid. “THE COURT: When you say see, you mean with your own eyes? THE WITNESS: Yes. THE COURT: Not with the use of microscopes. THE WITNESS: I don’t mean see with your own eyes in the sense you can see a molecule and you can sit there and count one, two, three, four. THE COURT: This is where I am having my trouble. How can you see something that you don’t see. THE WITNESS: . . . Because, Judge, you are asking how do the tools of all science work in general when you ask a question like that, and the way you see it is with some technical procedure that allows you to see the consequence of the molecule with a particular set of properties” (pp.55-56). TRUTH MACHINE ultimately instructs that all interpretive enterprises must pay close attention to the meaning of words.

Every scholar interested in science and law will find much of value in TRUTH MACHINE. It is a sophisticated book that does not easily fit standard courses, although it could be used for advanced seminars that explore the intersection of law and science. As I am not familiar with the curriculum in S&TS programs, I am not sure whether the book is useful for S&TS pedagogy, but given the prominence of the authors, I am sure that it will be considered there. Because the subject of wrongful convictions is one of the most exciting issues coursing through American law schools, teachers of criminal law who wish to gain a sophisticated understanding of DNA as evidence will find the book extremely valuable.

Kuhn, Thomas S. 1970 [1962]. THE STRUCTURE OF SCIENTIFIC REVOLUTIONS. 2nd Ed. Chicago, University of Chicago Press.

Melville, Herman. 1991. MOBY-DICK, OR, THE WHALE. New York: Vintage Books/Library of America.


R v. ADAMS, [1996] EWCA Crim 222, [1997] EWCA Crim 2474.

© Copyright 2009 by the author, Marvin Zalman.