Here’s a quick refresher on the United States Supreme Court’s expert witness trilogy:
First, in Daubert v. Merrell Dow Pharmaceuticals (92-102), 509 U.S. 579 (1993), the Court held that the Federal Rules of Evidence, not the Frye decision, provided the standard for admitting expert scientific testimony in a federal trial. Frye’s “general acceptance” test was superseded by the Rules’ adoption. The Rules placed appropriate limits on the admissibility of scientific evidence.
The task of ensuring that an expert’s testimony both rests on a reliable foundation and is relevant to the task at hand is a task assigned to the trial judge. The trial judge must make a preliminary assessment of whether the testimony’s underlying reasoning or methodology is scientifically valid and properly can be applied to the facts at issue. Considerations include: whether the theory or technique in question can be (and has been) tested, whether it has been subjected to peer review and publication, its known or potential error rate, and the existence and maintenance of standards controlling its operation, and whether it has attracted widespread acceptance within a relevant scientific community.
Second, in General Electric Co. v. Joiner, 522 U.S. 136 (1997), the Court held that the abuse of discretion standard was the proper standard for reviewing the trial judge’s decision to admit or exclude expert scientific evidence.
Finally, in Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999), the Court held that the Daubert factors may apply to the testimony of engineers and other experts who are not scientists. The Daubert “gatekeeping” obligation applied not only to “scientific” testimony, but to all expert testimony. A trial judge determining the admissibility of an engineering expert’s testimony may consider one or more of the specific Daubert factors. The abuse-of-discretion standard applies as much to the trial court’s decisions about how to determine reliability as to its ultimate conclusion. Whether Daubert’s specific factors are, or are not, reasonable measures of reliability in a particular case is a matter that the law grants the trial judge broad latitude to determine.