Qualifications and Testimony


Expert testimony continues to play an important role as we enter the twenty-first century; however, an expert’s scientific findings, no matter how important, have no real meaning in law until they are presented to the judge or jury.
This article will first examine the admissibility of scientific evidence, including the most recent United States Supreme Court decisions and proposed changes to the Federal Rules of Evidence. The article will next address experts’ qualifications and how to project credibility and expertise, through those qualifications, to a judge or jury. Finally the article will examine how jurors perceive expert witnesses. Various studies, conducted before and after the infamous O.J. Simpson trial, will be discussed in order to examine whether jurors’ perceptions of experts have changed.

Admissibility of Expert Testimony

The admissibility of expert testimony is an issue to be decided by the judge presiding over the case. In the United States there are two tests for admissibility, the older Frye test, or ‘general acceptance’ test, which received its name from the 1923 case of Frye v. United States, 293 F. 1013 (D.C. Cir. 1923). Frye dealt with the admissibility of the precursor of the polygraph. The Court stated the test as follows:
Just when a scientific principle or discovery crosses the line between the experimental and demonstrable stages is difficult to define. Somewhere in this twilight zone the evidential force of the principle must be recognized, and while courts will go a long way in admitting expert testimony deduced from a well-recognized scientific principle or discovery, the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs.
Id. at 1014. The Court held that the systolic blood pressure test had not yet gained recognition in the physiological and psychological communities, therefore the evidence was not admitted.
The Frye test was the test used by the majority of states and the federal courts in the United States for many years. In 1975, the Federal Rules of Evidence were enacted. Rule 702 provides:
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 an opinion or otherwise.
Therefore, to be admissible, such evidence need be helpful, relevant and reliable.
After 1975, there arose a question whether Rule 702 superseded the Frye test. In 1993, the United
States Supreme Court answered the question in the affirmative in Daubert v. Merrell Dow Pharmaceu-ticals,Inc, 509 U.S. 579, 113 S.Ct. 2786 (1993). In Daubert, the plaintiffs alleged that the ingestion of Benedictin, a prescription antinausea drug marketed by Merrell Dow Pharmaceuticals, caused birth defects such as limb deformation. The Supreme Court held that proof that establishes the scientific reliability of expert testimony must be produced before it may be admitted. Daubert requires that the judges become ‘gatekeepers’ of scientific evidence. Daubert requires the trial judges to decide whether the expert testimony will assist the trier of fact and whether it amounts to scientific knowledge, i.e. is the theory or test derived by the scientific method? The United States Supreme Court listed factors that the judges should consider in making their decision; however, the Court stated the list is not a definitive checklist, nor is one factor determinative:
1. Whether the proposition is testable.
2. Whether the proposition has been tested.
3. Whether the proposition has been subjected to peer review and publication.
4. Whether the methodology or technique has a known or potential error rate.
5. Whether there are standards for using the technique.
6. Whether the methodology is generally accepted.
When the Daubert case was remanded to the Ninth Circuit Court of Appeals to apply the factors, the Court held that the evidence did not amount to scientific knowledge and was therefore inadmissible. The Ninth Circuit also noted that the technique was developed solely for the litigation in the case and the proffered expert testimony was not based on independent research, thus not subjected to peer review and publication.
The Daubert ruling had a great impact on states that have evidence codes modeled after the Federal Rules of Evidence (by mid-1993 35 states had such evidence codes). At present, the majority of states have adopted the Daubert test of admissibility of scientific evidence, while a minority has retained the Frye test.
In 1999 the United States Supreme Court had to decide whether the ‘gatekeeper’ function of courts, as outlined in Daubert, reached the testimony of all experts, not just ‘scientific’ experts. Kumho Tire Co. Ltd. v. Carmichael, 119 S.Ct. 1167 (1999), involved a car accident that occurred after a tire ruptured. The survivors and decedent’s representative sued the tire’s manufacturer and distributor, alleging a defect in the tire caused the rupture, which led to the accident. The trial court excluded the plaintiffs’ expert’s testimony for failing to meet the Daubert criteria. The Eleventh Circuit Court of Appeals reversed, reviewing de novo the district court’s decision to apply Daubert. The Circuit Court ruled that the Daubert test is restricted to those cases involving ‘scientific’ evidence and not those involving skill or experience-based knowledge.
The Supreme Court reversed and held that the admissibility of expert testimony based upon technical or specialized knowledge should be subjected to the analysis and facts set forth in Daubert v. Merrell Dow Pharmaceuticals,Inc., 509 U.S. 579 (1993). The Supreme Court also reaffirmed that the Daubert factors were not restrictive, but flexible and should be applied on a case-by-case basis.
Commentators have agreed that the greatest impact of the Kumho Tire decision will be in the areas of ‘soft science’: handwriting, fingerprints, psychological testing, medical and psychiatric testimony, arson investigation, accident reconstruction, bitemarks and drug recognition experts. See ‘Court Developments: Daubert Applies to all Experts, Not Just “Scientific” Ones, High Court Holds,’ 13, No. 7 The Criminal
Practice Report 129,132 (April 7, 1999). Thus, the Kumho Tire decision is likely to open the door to litigation in these areas. Additionally, this decision will foster changes in the admissibility of, at least, some expert evidence.
At the time of the writing of this article there was a proposed amendment to Rule 702 of the Federal Rules of Evidence which reads as follows:
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 an opinion or otherwise, provided that (1) the testimony is sufficiently based upon reliable facts or data,(2) the testimony is the product of reliable principles and methods,and (3) the witness has applied the principles and methods reliably to the facts of the case.
This proposed amendment was drafted in response to the Daubert decision and to the many cases applying Daubert. ‘The amendment does not distinguish between scientific and other forms of expert testimony,’ Proposed Advisory Committee Note. The Committee Note also states that the court’s ‘gatekeeper’ function applies to testimony by any expert and that ‘[t]he trial judge in all cases of expert testimony must find it is properly grounded, well-reasoned, and not speculative before it can be admitted.’
The Committee Note points out that if a witness is relying primarily on experience to reach an opinion, the witness must explain how that experience leads to the opinion. The Committee Note cautions that the more controversial and subjective an opinion, the more likely the testimony should be excluded as unreliable. The amendment requires, in its revised format, that expert testimony must be based upon reliable and sufficient underlying ‘facts or data’. This ‘data’ includes reliable opinions of other experts.
Once a judge determines that scientific evidence is admissible, the judge must still address whether the probative value of the evidence is outweighed by prejudice or whether such evidence may confuse the jury. Federal Rule of Evidence 403 provides:
Although relevant, evidence may be excluded if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence.
The admissibility of expert evidence is a question of law that the judge decides. A judge’s decision will only be overturned on appeal if the appellate court determines the judge abused his or her discretion. The United States Supreme Court adopted the abuse of discretion standard for reviewing a trial court’s admissibility decision under Daubert in General Electric Company v. Joiner, 118 S.Ct. 512 (1997).


Once the issue of admissibility of scientific evidence is resolved, the judge must determine whether a witness is qualified to render an opinion as an expert. In the United States, the Federal Rules of Evidence state that a witness may qualify as an expert on the basis of knowledge, skill, training, experience or education.
An expert witness need only possess one of these traits for the judge to find the expert qualified to give an opinion. In making this evaluation, the judge may consider the expert’s educational background, work experience, publications, awards, teaching or training positions, licenses or certification, speaking or other professional engagements, prior expert witness testimony, and membership of professional associations. In the majority of jurisdictions, the determination of a witness’s qualification to express an expert opinion is within the discretion of the trial judge and will only be overturned for abuse of discretion. In the minority of jurisdictions, the appellate courts will not reverse the judge’s decision in the absence of a clear showing of error. Often, the expert may have to educate the attorney proffering the expert regarding the significance of particular experience, achievements and certifications to ensure that they receive the appropriate emphasis. An expert must be prepared to explain board certification and licensure in detail, including the recertification and relicensing requirements.

Experience as an Expert Witness

Experience and training are often more significant than academic background and are accorded more weight by jurors, according to a jury study evaluating fingerprint experts. See Charles Illsley, ]uries,Finger-prints and the Expert Fingerprint Witness, US Department of Justice (1987). However, experience as an expert witness, standing alone, does not qualify someone as an expert in later cases. For example in Bogosian v. Mercedes-Benz ofN. Am.,Inc, 104 F.3d 472,477 (1st Cir. 1997), the court rejected an opinion of a witness who had testified as an expert 126 times. One court even noted ‘it would be absurd to conclude that one can become an expert by accumulating experience in testifying’ – Thomas ]. Kline,Inc. v. Lenillard,Inc., 878 F.2d 791, 800 (4th Cir. 1989). Conversely, a lack of prior experience as an expert witness does not disqualify one from testifying as an expert. United States v. Locascio, 6 F.3d 924, 937 (2nd Cir. 1993) (‘. . . even the most qualified expert must have his first day in court.’).


An expert may be qualified based on his or her academic credentials, i.e. undergraduate, graduate and/or postgraduate work. While distance learning is the way of the future, the proliferation of the Internet has rekindled the old-fashioned diploma mill, so one needs to be careful to participate only in accredited programs. An expert also needs to keep up-to-date with developments in his or her field by reading the literature (journals, treatises, newsletters and topics), as well as through continuing education, joining professional societies and attending professional meetings.
Teaching experience is another of the qualifications that judges will evaluate; not only teaching as a regular faculty member, but guest lecturing, visiting professorship and teaching of continuing education and short courses all weigh in as credentials.
An expert also needs to keep researching and publishing. In the past, one of the criticisms of the document examination field was a lack of research and studies. See D. Michael Risinger, et al, “Exorcism of Ignorance as a Proxy for Rational Knowledge: The Lessons of Handwriting Identification Expertise,”‘ 137 U. PA.L.REV. 731 (1989) and D. Michael Risinger and Michael J. Saks, “Science and Non-science in the Courts: Daubert Meets Handwriting
Identification Expertise,” 82 IOWA L. REV. 21 (1996). That criticism has been rebutted. See Andre A. Moenssens, “Handwriting Identification in a Post-Daubert World,” 66 U.M.K.C. L.REV. 251 (1997) but the debate is still on-going. For a response to Professor Moenssens’ article, see D. Michael Risinger, Mark Denbenbeaux, Michael J. Saks in “Brave New ‘Post-Daubert World,’ – A Reply to Professor Moenssens,” 29 Stan L. Rev. 405 (1998).

Membership in Professional Associations

A study published by the Juries,Fingerprints and the Expert Fingerprint Witness United States Department of Justice (1987) found that jurors perceived those fingerprint experts who belonged to professional associations as more credible than other experts, and presumed experts would belong to such groups. Joining such associations aids in making contacts, interaction with peers and provides speaking and publishing opportunities as well as educational opportunities. At professional meetings experts have opportunities to hear and discuss cutting edge ideas and theories with their peers.
Annual payment of dues alone, in order to be a member of a professional association, is not as prestigious as having to be invited for membership or needing referees or requiring an examination for membership. It is important to remain active and participate aggressively in professional societies. The expert’s credibility is diminished if the expert has not attended a professional meeting recently.
It is wise for an expert to be selective about which professional associations to join. The February 8, 1999 issue of the Wall Street Journal of 8 February 1999 noted that the American College of Forensic Examiners, a 6-year-old organization, which already has 12 000 members, has ‘mail-order’ credentialing, for which the applicants must only pay $350.00 and pass an ethics exam. There were no examinations for board certifications in various specialties during their ‘waiver of examination’ periods – all one needed to do was verify possession of 200 ‘experience points’ and send in a fee.
The founder of the group is currently seeking to establish an Internet-based educational program that would offer PhDs in forensic science. So far, no college or university has decided to host the program. Elizabeth MacDonald, ‘The Making of and Expert
Witness: It’s In the Credentials,’ WALL ST J. Feb. 8, 1999, atB1.

Increased Scrutiny of Experts

Experts have come under increased scrutiny for either fabricating or inflating their qualifications. For example, in 1998, in Florida, a person who had been testifying as an expert in toxicology for 3 years, for both the prosecution and defense in criminal cases, was prosecuted for perjury for testifying with fraudulent credentials. A prosecutor noticed some discrepancies between two of the expert’s resumes and began checking into his claimed credentials. The expert claimed to possess a masters and doctorate degree from Florida Atlantic University. The registrar’s office had no record of his attending or of receiving a degree from the university. In fact, the university does not even offer a PhD. in organic chemistry, the program from which the expert claimed to graduate. The expert also handed out a copy of his master’s degree dated 1971. It was signed by ‘Lawton Chiles, Governor’. Chiles was a United States Senator in 1971. He did not serve as Florida’s Governor until 1991. The expert was eventually charged with three counts of second degree perjury (one count for each first-degree murder case in which the expert testified as a defense witness). The ‘expert’ pled guilty and received a sentence of 3 years in prison, followed by 5 years probation. See Henry Fitzgerald, Jr., “Phony ‘expert’ jailed for 3 years,”
FT. LAUDERDALE SUN SENTINEL, Dec. 1, 1998,at 3D. In addition to perjury prosecutions for false qualifications, some jurisdictions will also prosecute for academic fraud. For example, in Florida, a person making a false claim, either orally or in writing, to possession of an academic degree, or title associated with such a degree (e.g. PhD), is guilty of a first-degree misdemeanor. In addition, a licensed person may have his or her license to practice suspended or revoked. See Fla. Stat. ยง817.567 (1999).
In another matter, a Harvard Medical Professor was sued for trademark infringement for falsely claiming to be board certified by the American Board of Psychiatry and Neurology (ABPN) in five trials. The Board sought to seize the expert witness fees and treble damages – ABPN v. Johnson-Powell, 129 F.3d 1 (1997). (While seemingly in agreement that the expert had committed infringements, the trial court denied relief because it believed she was unlikely to infringe in the future. The appellate court affirmed, stating that the trial court did not abuse its discretion.)
Courts have also overturned convictions where the experts testified outside their field of expertise. For example, in Gilliam v. State, 514 So.2d 1098 (Fla. 1987), the court held the medical examiner was not qualified as an expert in shoe pattern analysis; therefore, it was an error for the trial court to allow her to testify that the defendant’s sneaker left marks on the decedent’s body. See also, Kelvin v. State, 610 So.2d 1359 (Fla. App. 1992), in which an evidence technician was found not qualified to give expert testimony about the trajectory of bullets depicted by dowels stuck into bullet holes in a sofa at a crime scene, as he was not a crime scene reconstructionist and had no training in ballistics.

Weight of the evidence

Once a judge decides that an expert may testify, the jury must then decide the weight to accord the expert’s opinion. Expert witnesses and attorneys should be aware of the studies that have been conducted regarding jurors’ perceptions of expert witnesses. These studies have shown that jurors give great weight to expert testimony. Many of these studies discuss jurors’ evaluations of the experts’ qualifications as well as the experts’ appearance, demeanor and communication skills.
In 1978 Rich Tanton published a study in the Journal of Forensic Sciences, ‘Jury Preconception and Their Effect on Expert Scientific Testimony,’ 24 J. FOR SCIS. 681 (1978). Tanton found that jurors held stereotypical views of experts: for example, the male expert was expected to be 44 years old, upper middle class, white, neat, intelligent, wearing a dark suit and glasses, professional, calm and serious; the female expert was expected to be white, 37 years old, dressed conservatively, neat, pleasant and honest.
In 1984, Saks and Wissler conducted a telephone survey of potential jurors. Michael Saks and Roselle Wissler, ‘Legal and Psychological Bases of Expert Testimony: Surveys of the Law and Jurors,’ 2 BEHAV. SCI. & L. 435 (1984). The respondents were asked the following: whether they would believe testimony from the experts; whether they perceive the testimony to be honest; and whether they perceive the witnesses from different fields to have adequate experience to testify. The study concluded that physicians, chemists and firearm experts ranked the highest in believability, honesty and experience. Next highest ranked were accountants, psychiatrists, psychologists and eyewitnesses. Lowest ranked were police officers, handwriting experts and polygraph experts.
Dr Joseph Peterson conducted three studies on forensic evidence and the courts from 1984 to 1987. Joseph Peterson, S. Mihajlovie, M. Gilliland, Forensic Evidence and the Police: The Effects of Scientific Evidence on Criminal Investigations, National Institute of Justice Research Report (Oct. 1984); Joseph Peterson, J. Ryan, P. Houlden, S. Mihajlovic, Forensic Science and The Courts: The Uses and Effects of Scientific Evidence in Criminal Case Processing, Chicago Center for Research in Law and Justice, U. 111. At Chicago (1986); Joseph Peterson, Use of Forensic Evidence by the Police and Courts, National Institute of Justice Research in Brief (Oct. 1987) (Ser. No.: NCJ 107206). His studies concluded jurors accorded great weight to expert testimony; the author of these found that in criminal cases in which expert witnesses testified for the prosecution, jurors were more likely to render guilty verdicts.
In 1992, the National Law Journal, a legal publication in the United States, conducted a survey of jurors and their views of the jury system. Joan Cheever and Joanne Naiman, ‘The View from the Jury Box,’ Vol. 15, No. 25 NAT’L. L.J., Feb. 22, 1993, at s2 col.1. The study concluded that jurors were influenced by expert witnesses and accorded their opinions great weight. In all the civil and criminal cases surveyed, 89% of the jurors thought the experts were believable. Overall 71% of the jurors said the experts made a difference to the verdict.
A more recent study of experts and jurors’ preconceived notions of experts was carried out in 1994 by Daniel W. Shuman, Elizabeth Whitaker and Anthony Champagne, ‘An Empirical Examination of the Use of Expert Witnesses in the Courts – Part II: A Three City Study,’ 34 JURIMETRICS J. 193 (1994). They conducted an extensive survey of American lawyers, judges, jurors and expert witnesses. A fascinating aspect of the study was the tabulation of the characteristics of experts that jurors considered important in determining the experts’ credibility. They determined the willingness to draw firm conclusions and the ability to convey technical information nontechnically were the most important characteristics of a credible expert.
Shuman, Champagne and Whitaker published another study, ‘Assessing the Believability of Expert Witnesses: Science in the Jurybox,’ 37 JURI-METRICS J. 23 (1996), which concluded that an expert witness’s believability was linked to the expert’s qualifications, familiarity with the facts of the case, good reasoning and perceived impartiality. Jurors were also influenced by independent research that corresponded with the expert’s opinion.
A 1997 study of jurors’ perceptions of expert witnesses in death penalty cases by Scott F. Sundby, ‘The Jury as Critic: An Empirical Look at How Capital Juries Perceive Expert and Lay Testimony,’ 83 VA. L.
REV. 1109 (1997) found that defenses based solely on expert testimony are likely to fail, but defenses that integrate expert testimony with persuasive lay testimony are more likely to prevail.
A 1998 National Law Journal/Decision Quest study Peter Aronson, David E. Rovella and Bob Van Voris, ‘Jurors: A Biased, Independent Lot,’ Nat’1 L.J., Nov. 2, 1998, at A1, exposes jurors as a more skeptical, cynical group. Among the findings, the study concluded that 50% of those surveyed think expert witnesses say only what they are paid to say; 33% do not believe police testimony; and 75% said they would set aside what a judge says the law requires and reach a verdict the jurors feel is right.


Expert testimony will continue to play an important role in the future. To be a more effective witness, an expert should be aware of the legal tests for admissibility of scientific evidence, the factors courts will evaluate in order to determine whether an expert is qualified to testify and jurors’ perceptions of experts.

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