Expert Testimony Expert Scientific Witness

Expert Testimony EXPERT SCIENTIFIC WITNESS TESTIMONY The Frye Decision and the Evolution of Modern Evidence Standards: The 1923 U.S. Supreme Court's Frye decision generated the criteria used by courts to determine the foundational qualification of proffered scientific expert witnesses in federal cases. Specifically, Frye introduced the general acceptance standard necessary to qualify the particular field of science supporting the intended testimony of expert witnesses (Cleary 2007).

According to the Frye criterion, in order for expert witness testimony to be admissible, the underlying field of science corresponding to the intended testimony, must be "generally accepted" within the scientific community. The Frye standard was widely adopted in state courts and persisted for 70 years, resulting in the exclusion of polygraph evidence and voice stress analysis (VSA) data. The significance of consensus in the scientific community remained the most widely accepted standard for the qualification of expert witnesses until 1993, when the U.S.

Supreme Court introduced a four-part test in decided the Daubert, finally resolving the Frye criteria and the wording of Federal Rule 702, enacted by Congress in 1975 (Burnette 2008). The Expansion of Criteria for Expert Scientific Witness Qualification: Whereas Frye required that the field of science involved by "generally accepted," in the scientific community, Daubert (and subsequent cases) expanded the possible foundation for the qualification of expert witnesses to include practical and vocational "experience" in 1993 without necessitating any specific generally accepted field of science (Burnette 2008).

In principle, Daubert significantly improved the prospect of introducing forensic fire investigators' testimony at trial, precisely by virtue of the role that practical experience and intuition plays in arson investigations in which no two cases are ever identical. The Daubert criteria consisted of two levels of inquiry, with the first emphasizing (1) the relevance, and (2) the reliability of proposed expert testimony; the second level of scrutiny under Daubert pertains to four criteria for determining the second element, reliability (Friedman 2005).

Under Daubert, the reliability of potential scientific testimony presented by expert witnesses was determined by (1) the objective controlled testability of the principle; (2) its prior publication in peer-reviewed publications; (3) ascertainable error rate; and (4) the degree of scientific acceptance within the community of the scientific discipline involved (McCormick 2007). The Inappropriateness of Frye to Fire Investigation: The field of fire scene investigation and forensic analysis incorporates scientific principles of combustion, thermodynamics, material science, mechanics, and chemistry.

However, no two fires are exactly the same and fire investigators rely very heavily on the cumulative knowledge of their practical experience and expertise. Frye set out a standard of foundational qualification of expert witness testimony that excludes the cumulative knowledge of even the most experienced arson investigator. Under the Frye criterion, much evidence that is directly relevant and extremely reliable is impossible to introduce at trial, simply because its elements are not represented by a specific scientific discipline capable of satisfying the qualification standard.

Some of the most important tools in the arsenal of the fire investigator include the senses of smell, touch, and physical manipulation. Likewise, the process of logical deduction often provides the correct forensic analysis of the evidence. Under Frye, crucial expert witness testimony relating to the practiced synthesis of the totality of circumstances disclosed by meticulous investigation is often excluded from use at trial. Certainly, Daubert provided additional flexibility of possible avenues capable of establishing foundational qualification of expert witnesses, but insufficiently to redress the problem.

Conclusion - Carmichael, Federal Rule 702, and Implications for Fire Investigation: The 1999 Carmichael case finally resolved the conflicting standards articulated under Frye and Daubert and their progeny since 1923 and 1993, respectively. In Carmichael, the Supreme Court specifically departed from the Frye standard and expanded the criteria introduced by Daubert to include non-scientific evidence as well as scientific evidence, suggesting that the Daubert court had never actually intended to restrict its ruling to the latter exclusively (Burnette 2008).

Carmichael emphasized the fundamental similarity of Daubert criteria to the purpose and effect of Federal Rule 702 (Burnette 2008) and recognized that certain fields of scientific and non-scientific expertise are demonstrably relevant and sufficiently reliable to satisfy the purpose of expert witness foundational qualification in principle. The impact of Carmichael on modern fire investigation expert witness testimony is two-fold and represents something of a dual-edged sword. On one hand, practical cumulative field experience is no.