Legalized gambling, beekeeping, or science? Judicial decision making about expert testimony in the aftermath of Daubert and Kumho.

摘要

The Supreme Court's decision in Daubert clarified the standards for the admissibility of expert evidence. Judges were called upon to evaluate the reliability of expert evidence, particularly the reliability of scientific evidence. The Court's decision in Kumho extended the reliability evaluation to non-scientific evidence. In the aftermath of these decisions, it was unclear how courts would evaluate expert reliability and whether these decisions would reduce the number of experts admitted to testify. This research investigated the effects of these decisions on expert testimony admissibility. To investigate the effects of Daubert, the first four studies evaluated over 1500 appellate court opinions on variables related to the admissibility of expert testimony. Analyses revealed that there was little change in the rates of admission of expert testimony in appellate courts. While experts in civil cases were less likely to be admitted after Daubert, the rate of admission of experts in criminal cases and for psychological experts did not change after Daubert. Even though the admissibility of expert testimony remained relatively stable after Daubert, several changes were observed in appellate courts' consideration of Frye (the most commonly-cited source of pre-Daubert factors), of the Daubert factors, and of several relevant Federal Rules of Evidence. Not surprisingly, the requirements of the Federal Rules of Evidence were reliably related to admission decisions. Although the Daubert factors were increasingly discussed by appellate courts, only general acceptance and general reliability predicted admissibility. In the final Study, this analysis was extended to investigate the effects of Kumho on judicial decision making about expert testimony. Contrary to expectations, expert testimony was more likely to be admitted after Kumho. As was true after Daubert, the Rules requirements were the strongest predictors of admissibility after Kumho. Overall, appellate courts appear to be evaluating the reliability of expert testimony as part of their admission decisions under the Rules, but they are not generally doing so by applying the Daubert factors.