In the legal system of the United States juries are comprised of groups of individuals who in all likelihood do not have the specialized training that pertains to the trial for which they have been chosen. Evidence that may be presented can include technical and scientific evidence that individual jurors or the jury as a whole may have trouble understanding and evaluating. The role of the expert witness is to explain the evidence in such a way as to make it understandable to the lay people in the jury box.
In the case of fire and arson evidence, the expert must be able to take a complicated and chaotic set of evidentiary material and provide a level of detail and understating so that the jurors can understand and utilize the evidence effectively during their deliberations. The qualifications of expert witnesses themselves are rooted in the Federal Rules of Evidence and case law. The National Fire Protection Agency (NFPA) provides guidance on the specific qualifications of an arson and fire expert witness.
The evidence given by an expert and how the expert testifies differs from other groups of witnesses.
The expert is testifying to a particular evidence set, is not an eye witness, and in all likelihood does not know anything of the parties involved. The expert’s testimony offers an explanation of technical facts to the jury. The expert will interpret results from testing, offer opinions based on the training and education the expert has acquired, and assists the jury in understanding relevant scientific theory.
The use of expert witnesses in court trials has been accepted for a long period of time. In Frye v. United States (54 App. D. C. 46, 293 F. 013), the defendant’s attorney stated, and the Justices agreed, that: “The rule is that the opinions of experts or skilled witnesses are admissible in evidence in those cases in which the matter of inquiry is such that inexperienced persons are unlikely to prove capable of forming a correct judgment upon it, for the reason that the Expert Witnesses and Testimony in Fire and Arson Cases Page 2 of 8 subject matter so far partakes of a science, art, or trade as to require a previous habit or experience or study in it, in order to acquire a knowledge of it.
When the question involved does not lie within the range of common experience or common knowledge, but requires special experience or special knowledge, then the opinions of witnesses skilled in that particular science, art, or trade to which the question relates are admissible in evidence” The issue in that case was not if the individual was qualified, but whether or not the test that the witness was testifying about qualified as being “sufficiently established to have gained general acceptance in the particular field in which it belongs. ” (Frye v. U. S. 1923).
The Justices admit that the question of when a theory, practice, principle, or discovery becomes accepted practice rather than a theory or an experiment is nebulous, but at some point the Court must decide if the evidence as presented qualifies for admission based on this acceptance (Frye v. U. S 1923). The Frye Test was in effect when Congress adopted the Federal Rules of Evidence in 1975. Federal Rule 104(a) addresses the preliminary question of the general admissibility of witnesses and evidence. According to that Rule, the attorneys will argue the case for and against the qualifications of witnesses and the admissibility of evidence.
The Judge will then rule as to the qualifications of that witness and the evidence. The Judge is not bound by the rules of evidence in making that determination, other than rules of privileges, such as attorney-client (Granados v. The State of Texas 2002). Federal Rule 402 provides that “All relevant evidence is admissible, except as provided by the Constitution of the United States, by Act of Congress, by these rules, or by other rules prescribed by the Supreme Court pursuant to statutory authority. Evidence which is not relevant
Expert Witnesses and Testimony in Fire and Arson Cases Page 3 of 8 is not admissible. ” (Daubert v. Dow 1993). This is the baseline for the admissibility of evidence, including testimony. Specific requirements for expert witnesses are found in Federal Rule 702. Federal Rule 702 states in part: “If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to 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 n opinion or otherwise. ” The Rule liberally defines an expert witness and does not require the theory, practice, or principle be accepted practice in the field in question, as did Frye. Thus, an expert witness is anyone who has some level of specialized training and/or experience in the field. The level of weight a jury will place on an expert’s testimony will of course be affected by the perceived level of competence that expert has in the eyes of that jury.
These two conflicting standards existed until 1993. In that year the Supreme Court issued an opinion in Daubert v. Merrell Dow Pharmaceuticals, Inc. that eliminated the Frye test. In that case Justice Blackmun, writing for the Court, noted that the general acceptance test was a cornerstone of the Frye decision, and that the Frye Test had been the dominant standard for the admissibility of new scientific evidence at trial for seventy years. Blackmun noted that the Federal Rules of Evidence would be evaluated like any other legislatively enacted statute. The rules in general were interpreted liberally and that was at odds with the rigidity of the Frye decision. In Beech Aircraft Corp v. Rainey the Court recognized that the general approach of the rules were to relax the barriers to opinion testimony (Beech Expert Witnesses and Testimony in Fire and Arson Cases Page 4 of 8 Aircraft Corp. v. Rainey 1988). Therefore Frye was incompatible with the Federal Rules of Evidence and should not be used in federal trials (Daubert v. Dow 1993). Blackmun does clarify that Rules themselves place a limit on whether or not supposedly scientific evidence can be admitted at trial. It is still incumbent on the judge to assure that the evidence is not only reliable but also relevant.
Rule 702 clearly regulates the admission of evidence. The evidence must be scientific, technical, or other specialized knowledge (Daubert v. Dow (1993). The subject of the testimony must be such that the scientific method applies. Knowledge implies that more than just subjective belief in the theory or practice exists. This is not meant to imply that the subject matter of the testimony must be regard as absolute fact. In science, there is little, if anything, that is considered fact. Science is simply a process for refining theories based on new evidence and discoveries.
To qualify as scientific knowledge, the evidence must have been derived form processes that utilize the scientific method (Daubert v. Dow 1993). Rule 702 also requires that the testimony or evidence aid the jury in understanding the testimony or evidence to determine a fact. This is the primary relevance test that is addressed in Rule 104(a). Evidence or testimony that does not pass the 104(a) test for relevancy would still not be admissible. This would require an assessment of whether the reasoning utilized to develop the evidence is scientifically valid (Daubert v. Dow 1993). An accepted manner to determine if a given theory is scientific knowledge that will assist the jury is whether or not the theory has been tested. Untested or untried theories do not have the same standing as those that have been tested. Repeatability of the outcome of the test is a Expert Witnesses and Testimony in Fire and Arson Cases Page 5 of 8 hallmark of the scientific method. A test that does not have a repeatable outcome falls short of the scientific method (Daubert v. Dow 1993).
Peer review of the theory will also assist the judge in making a determination as to the admissibility of the evidence. Publication of the theory, although not an absolute necessity, does submit the theory to the scientific community as a whole and the particular field of research in particular. This scrutiny increases the chances of any flaw in the theory being discovered (Daubert v. Dow 1993). The Daubert decision eliminates the “General Acceptance” provision of Frye as a precondition for the admissibility of technical and scientific evidence.
The decision reaffirms Court Rule 702 as the standard for expert testimony. The Rule does impose upon the Judge the responsibility to ensure that an expert’s testimony rests on reliable science and that it is indeed relevant. The decision states further that any relevant evidence that is based on scientifically valid principles will meet the demands of the Court Rules (Daubert v. Dow 1993). Taking the general definition of an expert witness and the admissibility of technical and scientific evidence under Rule 702 and applying it to arson and fire cause determination is problematic.
While determining if an investigator is qualified as an expert witness is fairly straight forward, the evidence that the expert will be testifying to is anything but. A fire investigator, like any other expert, must show that he based his opinions on reliable scientific principles. Fire investigation is basically a deductive process. The investigator will rely more on circumstantial evidence than on direct proof. In Commercial Union Insurance Co. v. Basfield, the court heard arguments that the investigator’s finding that the fire was most likely caused by the careless use of smoking materials should be excluded.
This argument was rejected, in part Expert Witnesses and Testimony in Fire and Arson Cases Page 6 of 8 because the court recognized that “because all direct evidence is often destroyed, fire experts often must rely on circumstantial evidence in determining the cause of a fire” The investigator had found no direct evidence that smoking was the cause of the fire, however other possible causes of the fire had been ruled out. Thus smoking was ruled by the investigator as the most probable cause. This was deemed adequate by the court, as this was a civil case.
In a criminal case a conclusive determination of the fire’s cause would be required. Such a determination, though, does not absolutely require direct evidence (Burnette 2000). The issue of deductive reasoning has been addressed by the National Fire Protection Association (NFPA) in NFPA 921, Guide for Fire and Explosion Investigations. Section 12-6 of the 1992 version of that document provided for four degrees of challenge with regards to the reliability of the opinion of the investigator. The most stringent challenge level, “a reasonable degree of scientific (engineering) certainty”, was on par with the proof required at a criminal trial.
The next was deemed “probably true”. This was defined as the level of proof needed to satisfy the rules of evidence for a civil trial. NFPA 921 stated that these were the two levels that met the certainty requirements of the scientific method. The other two challenge levels, “possibly true” and “suspected to be true”, were not to be used in an analysis or hypothesis. This version of NFPA 921 did state that the decision as to the truth of the collected data in the investigation and any conclusions drawn from that data rested with the fire investigator. Only that investigator could determine the level of validity of each piece of evidence.
It would be up to the jury to determine how credible that evidence and the investigator’s testimony was. The 1995 version of NFPA 921 changed the “four degrees of challenge” to “four degrees of confidence”. The NFPA also made these four levels a recommendation rather than a requirement. These four were now termed conclusive, probable, possible, and suspected. Expert Witnesses and Testimony in Fire and Arson Cases Page 7 of 8 Instead of tying the levels to the burden of proof at criminal and civil trials, the new standard set conclusive as the level that: the hypotheses has been tested and withstood all appropriate challenges while all reasonable alternatives to the hypothesis have been considered and eliminated due to their failure to withstand a valid challenge, leaving only that hypothesis under consideration as true. ” This definition of conclusive meets the requirements of Daubert. The evidence that would be admitted has undergone scrutiny and uses the scientific method. The 1998 version of NFPA 921 eliminated the four levels of confidence and simplified the wording. It states: “When forming opinions from hypothesis about fires and explosions, the investigator hould set standards for the degree of confidence in those opinions. Use of the scientific method dictates that any hypothesis formed from an analysis of the data collected in an investigation must stand the challenge of a reasonable examination. ” This version then cites Daubert v. Merrell Dow. NFPA 921 now leaves it entirely up to the investigator to determine an appropriate level of confidence in the conclusion of the cause and origin of the fire. The fire investigator is going to face three different challenges in giving expert testimony. The first is acceptance by the court as an expert witness.
This is not usually an issue, since all fire investigators have received specialized training and possess skill sets that the average lay person does not. The second challenge is that the investigator must base all of the investigator’s opinions upon scientific principles that are deemed reliable. Since the investigators conclusions are likely to be based on indirect evidence instead of direct roof, showing that these conclusions Expert Witnesses and Testimony in Fire and Arson Cases Page 8 of 8 meet the scientific method test of Daubert can be difficult.
The third challenge is for the investigator to reach the level of confidence required to support the findings and defend them under cross examination. Daubert has changed the face of expert testimony and evidence. While the new standard does not require “General Acceptance” as a prerequisite, it is still incumbent on the experts to be able to defend the evidence and testimony they are presenting at trial. The expert must have a clear understanding of the legal standards that must be met in order to succeed at trial, along with a documented set of credentials to convince the judge and jury of their status as an expert witness.