The Effective Evaluation of Expert Reliability

I. Introduction The admissibility of expert testimony has undergone an evolution in the United States since 1923, when the Supreme Court decided Frye v. United States.1 The Court in Frye established a standard for expert testimony admissibility.2 Under the Frye test, novel evidence was admissible only if its proponent demonstrated that the theory or technique underlying the expert's opinion was generally accepted in the relevant community.3 The Frye standard was used in federal courts for seven decades until 1993, when the Supreme Court liberalized the admissibility test in Daubert v. Merrell Dow Pharmaceuticals.4 The Daubert Court held that Federal Rule of Evidence 702, enacted in 1975, abandoned the traditional Frye test and that neither the text nor history of Rule 702 indicated an intent to retain Frye.5 In early 1999, Daubert was extended. The Supreme Court held in Kumho Tire Co. v. Carmichael6 that the trial court's gatekeeping function applied to all types of expert testimony offered pursuant to Federal Rule of Evidence 702. The Kumho Tire case represents a significant expansion of the trial court's gatekeeper role, which the Supreme Court had originally applied solely to scientific testimony in Daubert.7 Subsequent to Kumho Tire, before a trial court admits any type of challenged expert testimony, the judge now determine that the proffered testimony is both relevant and reliable.8 This inquiry is necessarily a flexible one, focusing on the expert's discipline as well as the application of the principles of that discipline to the facts of the case at issue.9 The focus of this Note centers on the that courts presently consider when analyzing the reliability of proffered nonscientific expert testimony and offers a possible foundation for unifying judicial standards related thereto. After Kumho Tire, admissibility of non-scientific expert testimony became problematic for trial judges, since Daubert factors10 are the only concrete test the Supreme Court has formulated. Trial judges are told to look at the facts and circumstances of a particular case and determine if Daubert are useful in determining admissibility.11 If not, additional factors may be considered to determine the reliability of the expert in question.12 Left with a liberal and fairly vague standard, trial courts in the various federal circuits have taken different paths to evaluate expert testimony. This Note analyzes the various courts presently employ and explains inconsistencies developing throughout the federal court system. This Note concludes with a proposed test for admissibility. II. History and Evolution of Expert Testimony In order to understand the nature of the current system, it is imperative to first trace the evolution of expert testimony through the federal court system. The evolution begins with Frye v. United States; continues with Federal Rule of Evidence 702, Daubert v. Merrell Dow, General Electric Co. v. Joiner,13 and Kumho Tire v. Carmichael; and has reached its current form with the recent amendments to Rule 702.14 A. Frye v. United States Faced with an increasing influx of expert evidence, the D.C. Circuit in 1923 attempted in Frye v. United States to establish a rigorous and systematic admissibility standard.15 The defendant in Frye had attempted to introduce expert evidence concerning a systolic blood-pressure deception test, a precursor to the modern polygraph test.16 The expert, who had conducted the test on the defendant, was offered as a witness either to testify about the results or to conduct another test before the court. The district court denied both of these offerings, and the defendant was convicted. Affirming the conviction, the D.C. Circuit considered the deception test along two fronts: probative function and prejudicial effect.17 The court chose to safeguard against prejudicial evidence by ruling that this evidence must be sufficiently established to have gained general acceptance in the particular field in which it belongs, thereby linking admissibility to credibility. …