Thoughts on Daubert and Expert Testimony

In the post-Daubert legal system, the need for reliable expert testimony in civil trials has taken great prominence. Couple this need to the increasing technical complexity of modern life (thus the parallel increase in complexity of issues tackled by the courts) and it is easy to appreciate the growing demand for experts who understand the legal framework, have impeccable credentials, and who can clearly communicate the significance of technical findings to attorneys, clients, and the trier of fact.

With the Daubert decision, the Supreme Court articulated the gatekeeping role for judges, affirming that judges have the responsibility to screen expert opinions for reliability before allowing their presentation in court and to exclude unreliable opinions (or “junk science”). Much has been written about the burden this standard places on judges who—with essentially no training in science or engineering—must somehow evaluate highly technical submittals on an immense range of topics (DNA evidence one day; petroleum geochemistry the next day; econometrics the next).

Not as much attention has been paid to the fact that the judges’ gatekeeper role provides a means for lawyers to challenge and potentially exclude expert testimony before a trial. In a 1998 survey, 41% of federal judges reported having limited or excluded expert testimony in recent cases. Because the “accusers” and the “gatekeepers” are lawyers, not scientists or engineers, it is na�ve to believe that only bad science gets excluded in this process (Dixon and Gill, 2001).

Environmental cases rely heavily on expert testimony; a single contamination case could require participation of a hydrogeologist, civil engineer, geochemist, toxicologist, risk assessor, physiologist and/or a groundwater modeler. For lawyers trying complex environmental cases, the stakes are high and selecting an expert who can survive Daubert challenges is paramount.