Psychological Expertise in Court

Psychology in the Courtroom, Volume II

Daniel A. Krauss, Joel D. Lieberman

• Publisher: Routledge
• Year: 2016
• Print ISBN: 9780754676874
• eBook ISBN: 9781317073895
• Edition: 1
• Topic: Psychology
• Subtopic: Sociology
• Index: Psychology

Expertise in Court: Perspectives on Testimony is the second of a two-volume set on the Psychology of the Courtroom. The authors, a renowned group of psychology and legal scholars, offer definitive coverage of the use of psychological expert testimony and evidence in a variety of legal contexts. They explore the controversies that surround it, from questions of its admissibility to its effects on eventual juror decisions. A wide range of topics are covered including system and estimator variables in eyewitness identification, expert testimony on psychological syndromes, the insanity defence and sexual harassment, how child sexual abuse is used by the courts, and recent research on false confessions. They also provide a comparative analysis exploring how different types of psychological expert testimony and evidence are used by different countries' legal systems. All the chapters conclude by making specific recommendations for how psychological research and information could be better utilized by courts around the world.

Chapter 1
The Admissibility of Expert Testimony in the United States, the Commonwealth, and Elsewhere

Daniel A. Krauss, Desiree Cassar and Allison Strother

Synopsis

As experts have become more essential to the determination of important legal decisions, courts have attempted both to allow important evidence to be available to legal decision-makers and to limit the “junk science” which enters the courtroom. This chapter explores the differences that exist in divergent legal systems’ attempts to grapple with the admissibility of expert testimony. It offers a critique of existing legal standards in the United States, Canada, Australia, England, and the Netherlands. In the end, it argues that while legal standards that control these issues differ considerably from country to country, factors outside the standards themselves often determine whether expert testimony in a particular case is admitted or rejected.

The Admissibility of Expert Testimony in the United States, the Commonwealth, and Elsewhere

As the twentieth century drew to a close, both advances in technology (e.g., DNA testing) and the complexity of litigation issues (e.g., whether certain work practices caused emotional distress in an employee) led to more frequent use of and greater importance being placed on expert witnesses in the legal system. For example, two surveys of United States federal judges performed by Krafka et al. (2002) indicated that experts were present in approximately 95 percent of surveyed judges’ civil cases, and that these cases averaged over four experts per trial. There was also growing concern that too much “junk science” was entering the courts, and that judges and jurors were being unfairly influenced by the cloak of science that surrounded unfounded expert testimony. For example, in the United States, the 1991 publication of Peter Huber’s Galileo’s Revenge: Junk Science in the Courtroom was seen as a watershed moment in this growing debate. Huber’s book offers a scathing attack on junk science-based expert testimony and discusses its damaging consequences, citing examples from a wide variety of less-than-scientific fields, including astrology, alchemy, and homeopathy. The book also documents expert testimony based on these pseudo-sciences serving as the pivotal link to liability judgments in a substantial number of civil cases.

Around the same time as the publication of Huber’s book, the proliferation and success of large scale mass tort lawsuits in the U.S. (e.g., asbestos and tobacco litigation) was garnering substantial media attention. In many mass tort cases, the causal link between the putative harm visited on a large group of plaintiffs by a corporation’s or an entity’s business practices is based almost exclusively on expert testimony. Without an expert to bridge the gap between the defendant’s conduct and the plaintiff’s injury, these cases have little chance of success. Bernstein (1996) suggests Huber’s critique as well as the media storm created by a number of astronomical monetary judgments in these cases raised the importance and profile of expert testimony admissibility decisions both within and outside the legal system.

The Role of Expert Testimony in the Legal System

Before discussing the substance of expert admissibility decisions by courts, it is first necessary to understand the unique role experts and their testimony play in the legal system. Experts are able to offer interpretations of events that they themselves have not witnessed. In contrast, ordinary witnesses are usually restricted to events they have directly experienced. Further, experts, based on their knowledge, experience, or research, are also allowed and called upon to offer opinions to courts about myriad topics while ordinary witnesses are restricted to factual statements. As a result, the admittance of expert testimony is often crucial to success in both civil and criminal trials. Yet, the very attribute that makes expert testimony most useful to the legal system, namely that it brings evidence and information to bear that is beyond the knowledge of the average jury or judge, also has made it increasingly controversial. It remains unclear whether sound, relevant expert testimony is aiding legal decision-makers in making better decisions or if overly persuasive but inaccurate expert testimony is confusing and misleading judges and jurors. In other words, the question remains whether the increasing use of experts is leading to more just outcomes or more injustice.

An Overview of Issues Surrounding the Admissibility of Expert Testimony

Courts world-wide are divided as to the appropriate standard for evaluating the admissibility of such testimony. Some courts have chosen to restrict greatly the amount of expert testimony that reaches the ears of the jury or fact-finders while others impose fewer restrictions on such testimony. Those courts opting for less stringency in their admissibility decisions assume that the fact-finders will be able to distinguish successfully between high and low quality expert testimony. The structure of legal systems themselves, however, may affect whether judges and jurors can accomplish this task. Adversarial systems, like that of the United States, rely on cross-examination and competing experts to educate the judge and jury about the weaknesses of expert testimony. In inquisitorial systems, the expert is often appointed from a pre-approved panel of the court and often little attempt is made to point out weaknesses of the expert testimony to the ultimate fact-finder, the judge.

Further, courts in different countries vary on how uniformly they apply their evidentiary admissibility standards. Some courts apply the same standard to all expert testimony regardless of whether the testimony is based upon particle physics or handwriting analysis. Other courts have applied different standards to evidence they believe is novel scientifically (e.g., DNA evidence) as opposed to expert testimony that has traditionally been admitted (e.g., foot print analysis) or is non-scientific in nature (e.g., the cost of medical expenses for injury). Yet, even in jurisdictions that apply the same uniform standard to all forms of expert testimony, substantial differences in decisions on the same evidence occur because these standards are applied divergently by human actors (i.e., judges).

In addition, certain forms of expert testimony, including forensic science evidence and behavioral and social science expert testimony, have engendered greater legal controversy than others. To date though, psychological expert testimony has played a relatively minor role in evidentiary admissibility jurisprudence. The heart of this chapter will outline the legal foundations that underlie evidentiary admissibility standards so that their application to psychological expert testimony can be understood in a broader context. This chapter will not provide a convenient reference guide as to what forms of psychological expert testimony will be admitted in a particular jurisdiction because it is simply not possible to easily predict how a judge will apply a particular standard. Rather, this chapter is intended to provide a framework so that the tradeoffs and controversies surrounding different types of expert testimony admissibility decisions can be better understood.

Recent Developments in Evidentiary Admissibility Standards

In the U.S., the significance of and controversy surrounding expert testimony in large-scale tort court cases paved the way for changes in expert testimony admissibility standards. Though this sort of litigation does not exist outside the U.S., Bernstein (1996) argues that evidentiary admissibility standards abroad faced a similar re-examination due to other legal developments. At the crux of the evidentiary controversy abroad were disputes involving forensic science expert testimony (e.g., DNA evidence, blood, hair and fiber analysis) and behavioral and social science expert testimony (e.g., Battered Women Syndrome, Rape Trauma Syndrome). For example, in an unusual Australian case involving the death of an infant, considerable controversy surrounded the admissibility of forensic evidence that purported to determine whether a child was killed by his mother rather than eaten by a dingo. This highly-publicized case, R. v. Chamberlain (1983), raised concern related to the admissibility of unscientific expert evidence at trial.

In the 1990s, the U.S. was the first country to enact substantial changes in its expert evidentiary admissibility practices. According to both Bernstein (1996) and Gatowski et al. (1996) the U.S.’s actions served as a significant catalyst for a rethinking of these same practices internationally. This chapter will examine: a) the factors that led U.S. courts to reevaluate their expert testimony admissibility procedures; b) the strengths and weaknesses of various evidentiary admissibility tests used in the U.S.; c) how these expert testimony standards have specifically affected the admissibility of psychological expert testimony; and d) how courts in Canada, the United Kingdom, Australia, and the Netherlands are currently approaching these issues.

A Brief History of Expert Testimony Admissibility Standards in the United States

The Frye Test

For 70 years in the U.S., the admissibility of novel scientific evidence and expert testimony was largely controlled by the standard announced in Frye v. United States. This 1923 District of Columbia Court of Appeals decision barred the admissibility of an early form of polygraph evidence. The part of this decision that became known as the Frye test required the judge to determine the admissibility of novel scientific information based upon whether it “… was sufficiently established to have gained general acceptance in the field in which it belongs” (Frye, 1923, p. 1014; emphasis added). This test is notable in a number of regards. First, while it required the judge to make the eventual admissibility decision, it deferred to the scientific community as to whether the evidence proffered was generally accepted. On the one hand, this delegation of authority kept judges from acting as amateur scientists. On the other hand, however, it prohibited scientifically sound, groundbreaking research from reaching jurors because it had not yet become generally accepted by the scientific establishment. Likewise, mainstream but inaccurate scientific evidence could be admitted by judges under this standard because the discipline had failed to recognize the errors associated with generally accepted thinking on a particular issue. For example, under this standard, courts in the mid-nineteenth century might have admitted expert testimony suggesting that the shape of an individual’s head controlled his/her dispositions (i.e., phrenology) because this was a widely held or generally accepted belief among scholars at the time.

Second, the range of expert testimony that the Frye standard applied to was initially unclear. Because the Frye test was adopted in a decision involving novel scientific evidence and expert testimony based on that evidence, it did not provide guidance as to whether this test applied to all forms of expert testimony or only those that involved new forms of scientific evidence. Subsequently, although some jurisdictions applied Frye to all expert testimony, the more common rule among U.S. jurisdictions was that it only applied to novel forms of scientific evidence. As Bernstein and Jackson (2004) argue, most U.S. courts adjudicated expert testimony which was not novel or scientific using other standards.

Third, the Frye test was criticized for its vagueness and likelihood of leading to inconsistent decision-making within and between jurisdictions. The lack of clarity in terms such as “the field to which it belongs” led to non-uniform application of this test by U.S. courts. For example, the interpretation of the general acceptance of polygraph evidence could be decided differently by two different courts depending on whether the court determines that the field it belongs to is polygraphy or science. Polygraphers would easily view such evidence as generally accepted in their field, while scientists would be more skeptical of the general acceptance of successful lie detection in their discipline.

The General Relevancy Approach

For the next 50 years the Frye test received much scholarly criticism, but as Sanders et al. (2002) point out, it was not until shortly after the adoption of Federal Rules of Evidence (FRE) in 1975 that controversy fully returned to this area of law. According to Bernstein and Jackson (2004) and Sales and Shuman (2007), the Federal Rules of Evidence were an attempt to codify a set of uniform evidentiary rules for the federal courts, but also were adopted almost in their entirety by every state court in the United States. Groscup et al. (2002) and Krauss and Sales (1999), among others, have argued that generally, the FREs have a “liberal thrust” towards the admissibility of evidence, allowing more evidence to reach the jury than common law rules would have allowed. The FREs also contain a number of rules that specifically govern the admissibility of expert testimony. Rule 403 states that any relevant evidence “… may be excluded if its probative value [is] substantially outweighed by danger of unfair prejudice, confusion of issues, or misleading the jury …”, and Rule 702 specifies that expert testimony is admissible if an appropriately qualified expert offers “… specialized knowledge that will assist the trier of fact [the judge or jury] to understand the evidence or to determine a fact in issue.” Since the FREs do not specifically mention the Frye test, it was unclear whether these new rules of evidence replaced the Frye general acceptance test (Sales and Shuman, 2005; Shuman and Sales, 1999).

Some U.S. courts held that FREs did replace the Frye test, and began applying a more relevancy-based approach to the admissibility of expert testimony (Bernstein 1996; Sanders et al. 2002). Under this standard, expert testimony or scientific evidence did not have to be generally accepted by the scientific community; it simply had to be relevant to the question being asked by the court. This approach, in keeping with the liberal admissibility elements of the FREs, adjudicated whether novel or other forms of expert testimony were not prejudicial according to Rule 403 and whether they could “assist the trier of fact” according to Rule 702. In order to assist the trier of fact, the court generally concluded that the proffered testimony had to be beyond the normal understanding of laypersons. Further, courts adopting this standard focused more on evaluating the credentials of an expert to determine if he/she was qualified to offer an expert opinion than they did on the scientific quality or general acceptance of the testimony being offered. Courts adopting this rule assumed that: a) jurors were capable of understanding and weighing even complex scientific information; b) jurors would not be unduly persuaded by a dubious expert in a particular case; and c) existing adversary procedures (e.g., cross-examination and competing experts) could ameliorate any bias caused by such an expert testimony. Unfortunately, the weight of empirical research that exists on this subject clearly suggests that many of these assumptions are incorrect.

Psychological research demonstrates that judges and jurors are often unaware of the limitations of expert testimony, and tend to rely on heuristic cues or cognitive short cuts rather than the content and quality of the testimony in evaluating and using expert testimony in their decision-making. An examination of the psychological decision-making theories relevant to this issue and the research based upon them, is beyond the scope of this chapter but is covered thoroughly elsewhere (see Chapter 3, in Volume I). In the end, the relevancy approach outlined by the FREs is best viewed as a generally less stringent admissibility standard than the Frye test.

Daubert and a Reliability Framework

Not all U.S. courts adopted a general relevancy approach following the promulgation of the FREs. Bernstein and Jackson (2004) suggest that some courts continued to apply the Frye test to novel scientific evidence while applying a general relevancy evaluation to other forms of expert testimony. As Bernstein (1996) and Sanders et al. (2002) note, still other courts began evaluating the reliability of the evidence that the expert offered. This latter standard would be the one adopted by the United States Supreme Court in 1993, in Daubert v. Merrell Dow Pharmaceuticals, when the Court attempted to clarify the confusion that surrounded expert testimony admissibility.

In Daubert, a group of individuals sued Merrell Dow Pharmaceuticals because they believed that the nausea drug that their mothers had been administered during pregnancy had caused their birth defects. At issue in the case was the admissibility of certain expert testimony, which was based on a re-evaluation of existing data using new methodology which provided proof of a link between the plaintiffs’ harm and the Merrell Dow’s drug. Originally, this expert testimony was not admitted by the trial court because the court reasoned the expert testimony offered did not meet the requirements of the Frye general acceptance test. Basing its decision on FRE 702, the Supreme Court reversed, holding that the lower courts had misapplied the rules governing the admissibility of expert testimony. They reasoned that the Frye test had been specifically superseded by the adoption of the FREs. Further, the decision offered a new evidentiary reliability framework for courts to use in evaluating the admissibility of expert testimony. The majority opinion did not, however, limit their interpretation of this standard solely to the wording of FRE 702, but rather the Court held that the scientific validity of the content of the expert testimony was the main issue for the court to use in determining admissibility (O’Connor and Krauss, 2001). Subsequent to the Daubert case, FRE 702 was rewritten to reflect more accurately the decision. The current wording of FRE 702 is “If the scientific, technical, or other specialized knowledge will assist t...

Table of contents

• Cover Page
• Title Page
• Copyright Page
• Contents
• Notes on Contributors
• Series Preface
• Preface to Volume II—Psychological Expertise in Court
• Preface to the Two-Volume Set
• Psychology in the Courtroom
• 1 The Admissibility of Expert Testimony in the United States, the Commonwealth, and Elsewhere
• 2 Psychological and Cultural Aspects of Interrogations and False Confessions: Using Research to Inform Legal Decision-Making
• 3 System and Estimator Variables in Eyewitness Identification: A Review
• 4 Insanity in the Courtroom: Issues of Criminal Responsibility and Competency to Stand Trial
• 5 Psychological Syndrome Evidence
• 6 Child Sexual Abuse and the Courts
• 7 Sexual Harassment: Antecedents, Consequences, and Juror Decisions
• Index