A tale of two sciences.

• Author: Murphy, Erin
• Position: DNA admissibility

THE DOUBLE HELIX AND THE LAW OF EVIDENCE. By David H. Kaye. Cambridge, Massachusetts and London, England: Harvard University Press. 2010. Pp. xvi, 330. $47.50.

GENETIC JUSTICE: DNA DATA BANKS, CRIMINAL INVESTIGATIONS, AND CIVIL LIBERTIES. By Sheldon Krimsky and Tania Simoncelli. New York: Columbia University Press. 2011. Pp. xviii, 406. $29.95.

"It was the best of times, it was the worst of times...." (1) So might one describe the contrasting portraits of DNA's ascension in the criminal justice system that are drawn in David Kaye's The Double Helix and the Law of Evidence (2) and Sheldon Krimsky and Tania Simoncelli's Genetic Justice: DNA Data Banks, Criminal Investigations, and Civil Liberties. (3) For Kaye, the double helix stands as the icon of twenty-first-century achievement, a science menaced primarily by the dolts (lawyers, judges, and the occasional analyst) who misuse it. For Krimsky and Simoncelli, DNA is a seductive forensic tool that is prone to overuse and best distrusted, as evidenced by swollen national data banks, shady police and laboratory practices, and unverified claims that the science has aided hundreds of thousands of investigations. Both books were written by experienced DNA insiders. Krimsky, a Tufts University professor and bioethics expert, and Simoncelli, formerly the Science Advisor at the American Civil Liberties Union, were both active participants in early academic and policy debates around DNA databasing. So too was Kaye, a professor at Penn State University, who has served on a number of government committees devoted to DNA methods and who has also aided defense lawyers in an assortment of cases. So whose picture is right?

To some extent, that depends on your assessment of these two additions to the expanding bookshelf of works devoted to charting the history of forensic DNA typing. (4) In key respects, the books are quite different and so do not obviously withstand direct comparison. Most significantly, they address different topics: Genetic Justice focuses on procedure--the collection and databanking of genetic information--whereas Double Helix is concerned with evidence--the admissibility and presentation of DNA results in court. (5) They are also aimed at different audiences: Genetic Justice is clearly pitched to a general lay audience, whereas the technical language and descriptive detail of Double Helix better suits more specialized readers.

But these otherwise very different books nevertheless produce two shared insights into DNA typing. The first, likely transmitted inadvertently, is that forensic DNA typing is inherently political. To be clear, both books are balanced in their approach, and the tone of neither could be described as strident. Yet the authors' own ideological perspectives on harnessing genetic information for law enforcement purposes inevitably colors both analyses. Given their divergent views, then, the other commonality is all the more revealing: both books ultimately advocate for heightened transparency and accountability in forensic practices. Although their specific prescriptions vary, all authors argue against the closed methods currently enjoyed. It is from these shared characteristics, which this Review illustrates sequentially below, that readers can derive the ultimate, and most beneficial, lesson taught by both books: first, that forensic DNA typing has never been, and is not now, a "neutral" science wholly separable from the politics of criminal justice; but second, that there are nonetheless some things that might be done to help foster its independence.

1. THE POLITICS OF DNA

   Because the books cover different aspects of the forensic use of DNA evidence--Genetic Justice focuses on investigative issues while Double Helix surveys the evidentiary treatment--there is no express relationship between them. Specifically, the aim of Genetic Justice is "to identify and define appropriate uses of DNA by law enforcement that will result in the furtherance of justice" (Krimsky & Simoncelli, p. xvii), while Double Helix "focus[es] on the appropriate application of the rules of evidence to the findings of scientists and technicians" (Kaye, p. xi). In short, while Genetic Justice is a contemporary story about cops on the street and computers in the lab, Double Helix is a historical account of lawyers and judges in the courtroom and scientists on the witness stand.

   Yet despite these immediate differences, the authors' diverging attitudes toward DNA typing remain fairly evident. Both books make implicit and explicit normative judgments about the role that DNA science should play in criminal justice. Moreover, because most of the material is familiar to regular consumers of the forensic DNA literature, comparative perspectives on the topics (or even specific events) addressed in each book are readily available. When considered in this light, as the next Sections explain, the books reveal a view of forensic DNA from two distinct vantage points. Krimsky and Simoncelli appraise DNA methods through the eyes of skeptics, explicitly cautioning against every new expansion in forensic DNA practices, whereas Kaye takes a more sanguine approach, welcoming the use of DNA to the criminal justice system and reserving his greatest disdain for the adversarial system that receives it in a manner he deems clumsy toward (and, he hints, corruptive of) the science itself. (6)

   1. ON THE STREETS: GENETIC JUSTICE

      Genetic Justice speaks in the language of the cynic. The authors open by questioning whether "increasing reliance on DNA in our criminal justice system [has] furthered our pursuit of justice" (Krimsky & Simoncelli, p. xv; emphasis omitted). They close by providing a qualified negative answer to that question, citing privacy, equality, accuracy, and efficiency objections to expansive DNA practices (Krimsky & Simoncelli, Chapters Fourteen through Seventeen). In a stream of measured arguments, Krimsky and Simoncelli seek to persuade readers that more DNA testing is not necessarily better, and in fact may actively be worse.

      The strength of Genetic Justice rests on its comprehensiveness. Krimsky and Simoncelli bring together a vast array of disparate materials that span a wide chronological spectrum and align them in order to afford a clearer view. Many scholars, myself included, have written on isolated aspects of DNA typing that are covered in the book, like familial searches, (7) dragnets, (8) phenotyping, (9) or sketchy collection practices, (10) but few have lined them all up next to one another to paint a stark picture of unrelenting expansion. Similarly, a handful of scholarly and policy reports have described the forensic practices of other countries, but few have juxtaposed them with one another--much less with the United States, and in a table!--to enable stark comparisons. (11)

      By collecting these materials together, Krimsky and Simoncelli clearly establish that the history of forensic DNA in the United States is one of unremitting growth, and issue an appeal to pause for reflection. Take note of how far we have come, they seem to plead through each account of a new development, and ask precisely what has been gained and lost as a result. They describe how DNA databases began as a limited experiment in collecting samples from a narrow class of convicted felony sex offenders (Krimsky & Simoncelli, p. 29) and have since burgeoned (the number of known profiles doubling every two years) into repositories that "stop[] just short, at least for the present, of including every person's DNA in a national network." (12) And whereas courts once struggled to reconcile the Fourth Amendment with status-based sampling of convicted offenders--some of whom had long before completed their official terms of supervision--the debate has so shifted that now mere arrestees and even innocent relatives are on the table (Krimsky & Simoncelli, pp. 36-38).

      To illustrate its point, Genetic Justice focuses on four different DNA tactics: dragnets, surreptitious sampling, familial searching, and phenotypic testing. For each, the authors offer critiques grounded both in fairness and accuracy terms. With respect to dragnets, they cite civil liberties concerns, adding that such sweeps typically reap little benefit in return. In fact, "[f]rom 1995 to 2005, about 7,000 people were tested in DNA dragnets in the United States" (Krimsky & Simoncelli, p. 62), and yet the single successful case arose in the context of a finite suspect pool, namely, employees at a nursing home (Krimsky & Simoncelli, p. 59). Surreptitious sampling, they contend, serves as a form of "backdoor to population-wide data banking." (13) Moreover, failing to regulate sneaky collection methods risks exploitation, especially since courts have proven reluctant to treat information-rich DNA samples as distinct from typed DNA profiles (Krimsky & Simoncelli, pp. 116-17). Familial searches represent a "fundamental shift in the intent and purpose of the database--from one of investigation of known offenders to its use as an intelligence tool" (Krimsky & Simoncelli, p. 84), and should raise concerns given the high rate of false positives that such searches can return (Krimsky & Simoncelli, p. 75). And lastly, they doubt the scientific basis of some proposed methods of phenotyping, such as the asserted ability to discern skin tone from ancestry (Krimsky & Simoncelli, pp. 103-04). But assuming such techniques could be improved, Krimsky and Simoncelli willingly embrace the use of DNA to discover "externally perceptible traits, such as hair color or stature, and nonsensitive internal or behavioral traits, such as voice type, lefthandedness, or absolute pitch" (Krimsky & Simoncelli, p. 106). Nevertheless, they caution against testing for more sensitive traits, in part for fear of starting down the familiar road of "'biologiz[ing]' crime and antisocial behavior" (Krimsky & Simoncelli, p. 98).

      Genetic Justice also engages the argument...