Assessing admissibility of nonscientific expert evidence under Federal Evidence Rule 702.

• Jurisdiction: United States
• Date: 01 October 1997
• Author: Oh, Peter B.
• Published date: 01 October 1997
• Author: Oh, Peter B.

A return to the general acceptance test of Frye would provide the best basis for courts to decide what nonscientific expert testimony should be heard

A former actor arranges to purchase marijuana. Over the next three years, he completes many transactions involving six persons and thousands of pounds of Colombian marijuana. He enjoys creating fictional plots, but he falls behind in his payments. After repeated and unsuccessful demands for money, the suppliers attempt to murder him. Before this plan can be implemented, however, federal agents arrest and charge all the individuals with conspiracy to import marijuana and operating a continuing criminal enterprise.

The former actor negotiates a deal with the government to testify as an expert on the marijuana's origin. Excusing the jury, the judge conducts a voir dire hearing. When asked to provide a qualifying basis for expertise, the former actor cites the "experience of being around a great deal and smoking" marijuana. The court admits him as an expert on identifying Colombian marijuana.(1)

This scenario is not an anomaly: nonscientific expert evidence is an increasingly common problem. A recent study concluded that approximately 40 percent of all expert witnesses introduced in civil trials decided by juries in California in 1985-86 were of the nonscientific variety.(2) That such evidence would become an integral part of the legal landscape was presciently foreseen by Dean Wigmore, who wrote that the introduction of expert knowledge in the courts "has done more than any one rule...to reduce our litigation to a state of legalized gambling."(3)

Since Wigmore's time, one enduring problem is that federal courts have had no established mechanism by which to deal with the growing influx of nonscientific expert knowledge. Until the enactment of the Federal Rules of Evidence in 1975, courts simply devised their own means for determining admissibility. Rule 702, "Testimony by Experts," states that "scientific, technical, or other specialized knowledge" is admissible only when shown that it "will assist the judge or jury in understanding or resolving a factual dispute." The evidence must be rendered by an individual qualified by virtue of "knowledge, skill, experience, training or education."

Although Rule 702 was an attempt to resolve the mess, its own ambiguities prevent federal courts from applying it in a consistent fashion. Courts have fashioned various common law standards to determine admissibility. These different standards demonstrate the need for harmony. In 1993, the U.S. Supreme Court held in Daubert v. Merrell Dow Pharmaceuticals Inc.,(4) a case which involved expert evidence about an anti-nausea drug being a human teratogen, that Rule 702 supercedes the 1923 "general acceptance" test of Frye v. United States.(5) But Daubert was a failure in two respects. First, it applies only to scientific expert evidence, and thus provides no assistance in determining the admissibility of nonscientific expert evidence. Second, it retains the Frye test as one among many factors to be used in assessing the admissibility.

Since Daubert, some courts have maintained that Daubert's reasoning can be applied to nonscientific expertise. Others have interpreted Daubert as being inapplicable to nonscientific expertise and have relied on Rule 702 instead. There must be a more promising test than these alternatives. Courts should reconsider the Frye test as the best way to determine the admissibility of nonscientific expert testimony. The "general acceptance" test is more effective than the current alternatives.

ADMISSIBILITY TESTS BEFORE RULE 702

The earliest experts in American courts typically testified about technical matters by virtue of their experience and training, for example, as engineers, physicians and shipmasters. Although skeptical about the competence of such witnesses, the Supreme erected a loose admissibility standard in 1854 in The Schooner Catharine v. Dickinson, in which it permitted testimony on a vessel's value but recommended that only experts "whose occupations and experience enabled them to express opinions... upon which [a] court might rely with some confidence in making up its judgment" be allowed to testify.(6) This subjective test served as the standard for admissibility until Frye.

1. "General Acceptance" Test

   Faced with an increasing influx of expert evidence, the D.C. Circuit attempted in Frye to establish a more rigorous and systematic admissibility standard. The defendant had attempted to introduce expert evidence concerning a systolic blood pressure deception test, a precursor to the modern polygraph test. 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 D.C. Circuit considered the deception test along two axes: probative function and prejudicial effect. Fearing that an inexperienced jury might impute an undue aura of reliability to a quasi-scientific test, however, the court chose to establish a standard designed to safeguard against prejudicial evidence. It ruled that such evidence "must be sufficiently established to have gained general acceptance in the particular field in which it belongs," thereby linking admissibility to credibility. The Frye test erected a threshold that required proposed expert evidence to be sufficiently recognizable by a court of law to be admissible.

2. Problems with "General Acceptance"

   Although adopted by most federal courts, the Frye test was heavily criticized. Commentators attacked the test for failing to define what actually constitutes "general acceptance."(7) One manifestation of the test's ambiguity was its inconsistent application in federal courts.(8) Moreover, "general acceptance" was a stringent standard that could exclude novel, but nonetheless valid, expert knowledge.(9)

   RECONCILING COMMON LAW ADMISSIBILITY TESTS WITH RULE 702

   Since the emergence of the Frye test, there have been two significant developments with respect to admissibility standards for nonscientific expert evidence. First, the Federal Rules of Evidence were introduced in 1975, creating a new standard of "factual assistance" that conflicted with Frye. The resulting divergence among federal courts prompted the second development--the attempt by the Supreme Court to resolve the issue in Daubert. The Court, however, inadvertently created a multi-factor test that applies only to scientific expert evidence.

1. Rule 702

   While Rules 703-705 also concern expert testimony, Rule 702 is the primary subject of controversy and the most relevant here. It provides:

   If scientific, technical, or other specialized

   knowledge will assist the trier of fact to understand

   the evidence or determine a fact in

   issue, a witness qualified as an expert by

   knowledge, skill, experience, training, or

   education, may testify thereto in the form of

   an opinion or otherwise.

   The rule requires a two-fold showing That (1) the proposed witness possess an acceptable degree of expertise on a "scientific," "technical" or "specialized" matter, and (2) the evidence will facilitate the resolution of a purely factual dispute.(10) It therefore does not explicitly recognize "general acceptance" as a means by which to determine admissibility.

   The first element of Rule 702--its demand for credentials--is problematic. While it establishes the factors that a federal court must consider to assess a witness's expertise, it fails to provide a threshold standard for the factors, both individually and collectively. Much of the current confusion about what constitutes admissible nonscientific expertise is traceable to this provision.

   The second element of Rule 702--its purpose--also is problematic. "Factual assistance" is a highly subjective determination of the trier of fact's capacity to benefit from the proffered evidence. For this very reason, some commentators propose more objective tests of whether expert knowledge is "beyond the ken of the average layman" or "not within the common knowledge of the average layman."(11) This task can be difficult in light of the diverse and wide pool of jurors in any particular case. Courts thus enjoy a significant degree of latitude under Rule 702 as to when expert evidence should be admitted or excluded.

2. Daubert

   Recognizing the tension between Rule 702 and Frye, the Supreme Court attempted to establish a definitive standard for assessing the admissibility of expert evidence. The majority, led by Justice Blackmun, concluded that under the Federal Rules of Evidence, no common law standard for determining admissibility remained. But the Court explicitly undermined its ruling by embracing reliability as the primary criterion for admitting expert evidence. That the Frye test was displaced by the Federal Rules does not mean, the Court held, that the rules themselves place no limits on the admissibility of "purportedly scientific evidence," retaining peer review as an important factor for determining the "general acceptance" of scientific evidence.

   Although refusing to establish a "definitive checklist or test," the majority nevertheless suggested multiple factors that should be considered whenever scientific expertise is weighed for admissibility. Among these are: testability, peer review or publication, the known or potential rate of error, and widespread acceptance.

   But this embrace of reliability was qualified. According to the majority, while "scientists typically distinguish between `validity' (does the principle support what it purports to show?) and `reliability' (does application of the principle produce consistent results?)," whenever there is case involving "scientific evidence, evidentiary reliability will be based on scientific validity." Daubert thus collapses the scientific standards of reliability and validity into a legal...