Fire in the Hole: Empirical Testing of a Pro-Government/Anti-Plaintiff Bias in the Admissibility of Scientific Experts in Criminal and Civil Cases

Abstract

This article examines the highly debated topic among sociologists, legal scholars and policy makers regarding the differential admissibility of expert evidence in criminal and civil cases. The U.S. standards and principles of the admission of scientific and non-scientific expert testimony has been greatly influenced by the U.S. Supreme Court decision of Daubert v. Merrell Dow Pharmaceuticals, Inc. and concurrent cases commonly referred to as the Daubert trilogy. These cases have produced substantial legal commentary and some empirical research examining their effect on case outcomes and judicial behavior. Anecdotal evidence based on experience and case studies report a differential treatment of expert evidence in criminal and civil cases. In criminal cases, legal scholars complain that admissibility standards are applied too leniently favoring the admission of the prosecution’s experts over criminal defendants, suggesting a pro-government bias. Conversely, under the same admissibility standards, in civil cases, legal scholars complain that the standards are applied more strictly than in criminal cases and that expert evidence proffered by plaintiffs are scrutinized more rigorously than those proffered by civil defendants, suggesting an anti-plaintiff bias. Despite the perceived consensus among legal and socio-legal scholars about this bias, there has been little empirical research testing this phenomenon. The current study quantifies and systematically records the frequencies of the admissibility of a single form of expert evidence, cause and origin of fire experts, as proffered by prosecutors, criminal defendants, plaintiffs and civil defendants in criminal and civil cases. By holding the type of expert evidence constant between the types of cases and legal actors, we can empirically test the proposed pro-government/anti-plaintiff bias that has been conventionally accepted in the socio-legal literature based largely on anecdotal evidence.