On March 23, 1999, the United States Supreme Court, in Kumho Tire Company Ltd. v. Carmichael, No. 97-1709, held that a trial judge may subject expert testimony based on "technical" and "other specialized" knowledge to the same rigorous standards previously placed upon "scientific" testimony. In reaching this decision, the Court extended its earlier holding in Daubert v. Merrell Pharmaceuticals, 509 U.S. 579 (1993), which required trial judges to act as "gatekeepers" to ensure that scientific evidence be not only relevant, but also reliable, before admitting it into evidence.
In Kumho Tire, the plaintiff's car overturned when his tire blew out, killing one passenger and injuring several others. The survivors sued the manufacturer, claiming that the tire was defective. The plaintiff's presented an expert witness, an engineer, who opined that based on his visual inspection of the tire, and in the absence of at least two physical symptoms of tire abuse, the failure was due to a defect in the tire. The engineer offered this opinion, despite the fact that the tire was five years old and had been inadequately repaired. The manufacturer moved to exclude the testimony on the grounds that the expert's methodology failed to satisfy the reliability requirements of Federal Rule of Evidence 702, as well as those set forth in Daubert. The trial judge agreed, and eventually granted summary judgment in favor of the manufacturer. On appeal, the Eleventh Circuit Court of Appeals reversed, holding that the restrictions of Daubert were only applicable where the expert witness relies on the "application of scientific principles", rather than "on skill or fact based observation." Carmichael v. Samyang Tires, Inc., 131 F.3d 1433, 1435-1436 (11th Cir. 1997).
The Supreme Court, in reversing the Eleventh Circuit, held that this basic "gatekeeping function" of trial judges applies to all expert testimony, and not just that based on scientific knowledge. Specifically, the Court held that Rule 702 makes no distinction between "scientific" knowledge and "technical" or "other specialized" knowledge. The Court noted that Daubert addressed only "scientific knowledge" because the expert testimony at issue in that case was based on scientific knowledge. The Court emphasized that the Daubert analysis is flexible, and that the trial judge is not limited to those specific factors listed in Daubert in determining whether or not to admit expert testimony. Finally, the Court found that it would be "difficult if not impossible" for judges to administer evidentiary rules that depended upon a distinction between scientific and technical knowledge, since there is no clear line dividing one from the other. In a separate concurring opinion, Justice Scalia noted that the purpose of the judge's discretion is to exclude "expertise that is fausse and science that is junky."
This decision is quite significant, since it will now subject experts in all fields, not just the traditional sciences, to greater scrutiny and possible exclusion if their testimony is not deemed reliable under the Daubert criteria. While this case applies to all Federal courts, many state courts, while not technically bound by the decision, will likely follow suit, particularly those whose rules mirror the Federal rules.