Articles of Note: Three Forthcoming Articles on Expert Testimony
Do Jurors Give AppropriateWeight to Forensic Identification Evidence?
William C. Thompson (UC-Irvine),Suzanne O. Kaasa (Northrop Grumman), Tiamoyo Peterson (UC-Irvine)
Journal of EmpiricalLegal Studies, Forthcoming
Is Expert Evidence Really Different?
Frederick Schauer (University of Virginia School of Law), Barbara A. Spellman (University of Virginia School of Law),
David Bernstein (George Mason University School of Law)
Notre Dame Law Review, Forthcoming
Abstracts below the fold . . .
Do Jurors Give Appropriate Weight to Forensic Identification Evidence?
William C. Thompson (UC-Irvine), Suzanne O. Kaasa (Northrop Grumman), Tiamoyo Peterson (UC-Irvine)
Journal of Empirical Legal Studies, Forthcoming
Abstract:
Do jurors giveappropriate weight to forensic identification evidence? When judging the valueof forensic evidence, are they sensitive to the probability of a false match?To answer these questions, we conducted two jury simulation experiments — thefirst with undergraduate participants, the second with members of a county jurypool. The experiments examined the weight that participants gave to forensicDNA evidence relative to Bayesian norms when evaluating a hypothetical criminalcase. We found that aggregate judgments were generally consistent with Bayesianexpectations, although people over-valued the DNA evidence when the probabilityof a false report of a match was high relative to the random match probability.Judgments of the chances the defendant was guilty varied appropriately inresponse to the variation in the probability of a false report of a match, asdid verdicts. Our findings refute claims that jurors are always conservativeBayesians when evaluating forensic evidence and suggest, instead, that they usea variety of judgmental strategies and sometimes engage in fallaciousstatistical reasoning. In light of these findings, we identify circumstances inwhich forensic evidence may be over-utilized, discuss implications for legalpolicy, and suggest additional lines of research.
IsExpert Evidence Really Different?
FrederickSchauer (University of VirginiaSchool of Law),Barbara A. Spellman (University of VirginiaSchool of Law),
Abstract:
Daubert v. Merrell DowPharmaceuticals, which along with its successor cases has imposed demandingstandards of reliability on the admission of scientific and other expertevidence, has transformed much of American evidence law. The Daubert revolutionhas been subject to strong endorsement and equally strong criticism, but fewcritics, and none since Daubert, have asked why expert evidence is treateddifferently in the first place. The common assumption, going back over acentury, is that expert evidence is treated differently because of the riskthat juries (and judges), not themselves possessed of the relevant expertise,will systematically overvalue such evidence. The overvaluation may be based onignorance, or on novices being overly impressed by expert credentials andtrappings, but the belief in overvaluation as the primary foundation for thedistinct treatment of expert evidence persists, generating not only Daubert butalso a long history of treating expert evidence specially. It turns out,however, that the longstanding assumption of overvaluation is unsupported bythe research. Several decades of research, mostly by psychologists, shows thecommon assumptions of jury overvaluation of expert evidence to be largeunfounded. Indeed, modern research shows that it is eyewitness and otherso-called direct evidence that is overvalued. By relying on the erroneousassumption of jury overvaluation of expert testimony and the equally erroneousassumption of non-overvaluation of direct testimony, the law of evidence hasdrawn a distinction that rests on a false empirical basis. Moreover, insofar asthe distinction between expert and other evidence also rests on a distinctionbetween the facts that lay witnesses offer and the inferences (opinions) thatcome from experts, this distinction is undercut not only by the moderntreatment of lay opinion, but by a great deal of philosophical work on theexpert-dependence of the judgments that ordinary people make in all aspects oftheir lives.
David Bernstein (George Mason University School of Law)
Notre Dame Law Review, Forthcoming
(from the) Abstract:
This Article reviews thehistory of the evolution of the rules for the admissibility of expert testimonysince the 1980s, the revolutionary nature of what ultimately emerged, and theconsistent efforts by counter-revolutionary judges to stop or roll back thechanges, even when the changes were codified into Federal Rule of Evidence 702.
. . .
This Article concludes by discussing some of the factors that have led somefederal judges to defy Rule 702. The author contends that the Supreme Courtshould take an appropriate opportunity to crack down on such judicialrebellion, for two reasons. First, Rule 702 is the law of the land, and federaljudges are obligated to enforce it regardless of their personal views on whatexpert testimony should be admissible. Second, Rule 702 represents aconstructive effort to confront the problem of adversarial bias while retainingthe basic contours of broader adversarial process.
– JB