Author: Matthew Dowd


Book Review: David Kaye’s The Double Helix and the Law of Evidence

The Double Helix and the Law of Evidence by David H. Kaye.  Harvard University Press: Cambridge 2010, pp. 352. $45.00.

“If it doesn’t fit, you must acquit.”

— The late Johnny Cochran, September 1995.

Almost fifteen years have passed since O.J. Simpson was acquitted of the double murder of Nicole Brown Simpson and Ronald Goldman.  Called the trial of the century, the Simpson case is still seen as a key point in legal history, even though the case created no significant legal precedent.

Experts at the time were still debating fundamental questions about the reliability,  acceptance, and admissibility of DNA testing.  The Supreme Court had handed down its watershed opinion in Daubert only a few years earlier.  As Professor David Kaye explains in his new book The Double Helix and the Law of Evidence, Simpson’s attorneys challenged the admissibility of the DNA evidence on numerous grounds.  But, at the end of the day, the most memorable moment of the trial is not the arcane issue of whether experts correctly calculated genetic probabilities using statistical estimation methods but Johnny Cochran’s statement in his closing, “If it doesn’t fit, you must acquit.”

Professor Kaye, distinguished professor of law and Weiss Family Faculty Scholar at Penn State Law, offers far more than just an account of the Simpson DNA evidence.  Kaye provides an in-depth review of how the law of DNA evidence progressed from its beginnings in the 1980’s to its current state.  His book is, in his own words, “part history, part legal analysis, part popular science, and part applied statistics.”  Kaye provides vignettes of many key developments in DNA evidence, from the first conviction and first exoneration based on DNA evidence in the 1986 Pitchfork case to the Simpson case to the use of mitochondrial DNA in analyzing the remains of Tsar Nicholas II and his family.  Kaye also examines legal milestones, such as People v. Castro, 545 N.Y.S. 985, 999 (Sup. Ct. 1989), in which Barry Scheck and Peter Neufeld convinced Judge Gerald Scheindlin to restrict the admissibility of the prosecution’s DNA evidence because the private testing laboratory “failed in several major respects to use the generally accepted scientific techniques and experiments for obtaining reliable results, within a reasonable degree of scientific certainty.”

Kaye’s book is not what I expected from the title, but surprises can be pleasant, as was this one.  Kaye draws from his substantial experience and his prior legal scholarship to create a concise and highly readable text devoted to the basics of DNA evidence and its historical development.  The book is not a comprehensive analysis of legal precedent governing DNA evidence, but that was not Kaye’s goal.  As Kaye explains, his work “is a tale of scientific egos, journalistic hype, lawyerly maneuvering, and judicial doctrine and disposition.”  Kaye starts the tale with biological evidence before DNA, such as the common A, B, and O blood types, and moves through the various stages of how courts and litigants reacted to the new actor on the legal stage.

Kaye’s explanations of the intricacies of DNA evidence are accessible to lawyers not having any specialized scientific training.  Kaye details the contributions of the major players, including experts such as Richard Lewontin, Daniel Hartle, and Eric Lander, lawyers Scheck and Neufeld, and the 1992 and 1996 reports of the National Research Council.  Kaye similarly explains the now classic “prosecutor’s fallacy” as applied to DNA evidence.

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