Expert Witness And The Legal System Research Paper

1. What Is An ‘Expert’ Witness?

An expert witness is one who, by virtue of education, training, and experience, is able to assist the trier of fact (i.e., judge or jury) in understanding scientific or other specialized knowledge that is beyond the ken of the average person. For example, an expert might discuss methods or materials for building bridges that laypersons or nonprofessionals might not normally understand, such as principles of engineering or the stress that particular alloys can withstand.

The evidence and subject matter on which experts may rely and testify about differ from lay witnesses in at least two fundamental ways. First, lay witnesses may testify only as to what they have done or observed directly and cannot offer conclusions or opinions based on those matters. In contrast, experts may offer opinions and interpret the facts at issue so as to assist the judge or jury in understanding technical or scientific materials that they might not otherwise be able to grasp sufficiently. For example, a lay witness might be limited to describing a person’s appearance or testifying that an individual talked about suicide, but an expert in psychology might be able to discuss the scientific literature related to depression and its treatment, and draw conclusions about cause and prognosis in a given case.

Second, experts are often permitted to review and describe various forms of evidence that might be deemed inadmissible with lay witnesses, such as statements within learned treatises or other types of materials usually classified as hearsay. For such evidence to be admissible, it should be of a type that experts in the respective area normally rely upon in formulating conclusions or opinions. For example, psychologists may routinely draw inferences from the written notes and reports of other professionals to analyze an individual’s psychological state at a certain point in time.

To the extent that an expert is qualified to make a unique contribution to the understanding of the factfinder, that testimony may be admitted. However, if an expert’s testimony is deemed to be within the scope of laypersons’ understanding, it may be barred. For example, if the expert is merely reiterating another individual’s statements absent any additional interpretation, or describes conditions or events that are within the common experience of most people, that testimony may be excluded. Expert testimony must also be deemed relevant to the issue at hand. Thus, a world authority might not be allowed to testify on the psychological effects of trauma if trauma is not at issue in the case. Expert testimony may be barred completely or partially in a given case. For example, an expert might be allowed to testify about the presence of a disorder but not its cause.

Although the expert’s defined role of ‘assisting the jury’ may sound neutral, in practice, one or the other side in a legal case usually retains a particular expert in order to advance that side’s position. This does not mean that experts are necessarily partisan advocates who provide whatever testimony will help the side that has retained them. A forthright expert operating in a fair and scientific manner may well reach a position consistent with that the retaining attorney hopes or plans to put forth. However, in part because experts often become involved in issues or questions that are complex or ambiguous or that have been the subject of research with conflicting results, and also because, unfortunately, some experts are less than forthright, it is very common for both sides to retain their own expert and for these experts to reach and present opposing conclusions. Such ‘battles of experts’ have been a source of much criticism and lead to the perception, sometimes correct and sometimes not, that expert testimony has simply been bought from ‘hired guns.’

2. The Role Of The Expert Witness

Expert witnesses began to appear in England during the thirteenth century in the form of specially commissioned juries of experts who heard or investigated matters related to their trade, or expert individuals who consulted directly with judges in areas where scientific or technical expertise was desired. As the judicial process evolved over the past 800 years to its current adversarial form, expert witnesses became increasingly less likely to be appointed by the court as fact-finders or neutral advisors (Landsman 1995). Today, expert witnesses are usually retained by, and testify for, specific parties to a legal issue, although under some circumstances judges may seek additional consultation or advice separate from the legal proceedings when deciding an issue. An expert witness may also be selected by a judge, or the parties in dispute may agree upon an expert. In addition, psychologists who were originally involved in a treating role may be asked to testify about the individual for whom they provided services.

In the early history of expert witnesses, physicians were most likely to address issues related to mental health. However, as psychology and allied disciplines established themselves as independent specializations, such matters increasingly became the domain of these fields. Today, expert witnesses in psychology testify in a wide variety of civil and criminal cases and in various adjudication situations such as civil commitment and different matters heard in family or juvenile court. The standards for granting an individual expert status vary in different jurisdictions by statute, precedent, tradition, and judge, and no universal standard exists. Additionally, the rules regulating the use of experts are subject to abrupt change as a result of new legislation or court decisions. However, some general characteristics and trends can be discussed.

In the criminal setting, a psychologist may testify as to a defendant’s competency to stand trial or participate in various facets of the investigation, prosecution, and disposition of a case (e.g., competency to confess, to waive legal rights, or to enter a ‘guilty’ plea). A psychologist may offer opinions about the defendant’s mental state at the time of the offense, in particular when an insanity defense is raised, or offer testimony related to psychological conditions or diagnoses that might mitigate or contribute to the defendant’s responsibility (e.g., brain damage leading to poor impulse control or the effects of alcohol and drugs). Psychological research on various aspects of trial proceedings (e.g., the degree to which jurors follow a judge’s instructions) and evidence (e.g., the reliability of eye-witness testimony) may also be introduced during trial as each side attempts to make its case. A psychologist may also become involved during the sentencing phase of a criminal trial, where the prospects for rehabilitation, the prediction of recidivism, and the severity and appropriateness of different sentencing options (e.g., incarceration vs. treatment) are at issue. For example, a psychologist may testify that an individual is, and will remain, a serious threat to society due to a high likelihood of future violent behavior.

In civil cases, psychologists may be called on to help establish or refute claims of psychological injury and distress. Testimony in these cases may involve the presence or absence of injury or disorder, the cause of disorder, and the effects or damages involved with a condition, such as employment prospects, needed treatment and associated expenses, pain and suffering, and decreased involvement in, or enjoyment of, pleasurable activities.

Psychologists often serve as expert witnesses in cases where civil commitment or competency is at issue. Civil commitment refers to the involuntary hospitalization or restriction of an individual’s liberty in order to prevent harm to self or others as a result of mental illness or incapacity. Competency hearings may involve such issues as the ability to manage one’s own finances, create a will, or enter into binding agreements.

Within the family court system, psychologists may address the best interest of children in custody disputes, and participate in the investigation and disposition of allegations of child abuse or neglect. In custody disputes, it is not uncommon for judges to have the parties agree upon a single expert for a particular issue, such as the adequacy of parents’ child-rearing capacities. For a detailed review of the various roles of psychologists in the court, see Melton et al. (1997). Monahan and Walker (1994) provide an overview of relevant case materials.

3. The Expert In The Legal Process

What occurs from beginning to end, when an expert becomes involved in a legal case, can vary widely, and hence a typical or common scenario is presented here. Initially, an expert is retained by an attorney and begins a review of the case. This may include an examination of various documents and reports, relevant scientific literature, and, in some cases (but not all), an examination of the individual or individuals whose psychological state is at issue. Based on this review, the psychologist, if possible, will then draw conclusions and present these in some manner (e.g., orally or in writing) to the attorney. In some situations, even if the attorney does not wish to maintain further involvement with the expert and does not want that expert to testify, these opinions must be disclosed to the other side; in other cases no disclosure is mandated. If the attorney does want to use the expert as a potential witness, that expert’s opinions usually must be disclosed at some point before trial. The attorney usually must file some description, based on the expert’s input, of the expert’s qualifications, the materials reviewed and depended upon, and the expert’s conclusions. The nature and level of detail required in the disclosure varies greatly in different jurisdictions.

Following disclosure, various steps may be taken by the other side to learn more about the expert and the expert’s methodology and opinions. The opposing attorney may file interrogatories, or written questions to which the expert, via the retaining attorney, must provide sworn written answers. In many jurisdictions, attorneys may depose opposing experts. Discovery deposition involves giving sworn testimony under questioning by lawyers. During deposition, experts may be asked about such issues as their experience, training and education, credentials, the nature and bases for any conclusions they may draw as well questions about various professional, theoretical, and technical issues. Much or all of the questioning will be conducted by the opposing attorney although the retaining lawyer may also ask some questions, usually at the end of the process, either to clarify or ‘fix’ what might seem to be earlier problematic answers or to establish certain strong points to gain leverage for settlement. Deposition does not occur in front of the judge or jury, but the expert is under oath and a court reporter makes an official transcript.

The purpose of these discovery activities is to avoid ‘trial by ambush’ or surprise, by allowing attorneys the opportunity to understand and prepare for the testimony that the expert is anticipated to provide. In addition, more complete understanding of the strengths and weaknesses of each side of the case may well facilitate agreement between the parties and foster a pretrial settlement.

If the case gets to trial (which in fact is unusual because a high percentage of cases are settled before that time), the expert’s court appearance begins with a swearing in. Before the expert states any opinions, the retaining lawyer will usually ask questions to establish the witness’s credentials and expertise. At some point the attorney then asks the judge to admit or qualify the witness as an expert. Prior to the judge’s ruling, the opposing attorney may then challenge the psychologist’s qualifications. The lawyer may seek restrictions on the scope and nature of the expert’s testimony or to have the expert excluded from testifying al- together.

What follows next (assuming that the expert has been qualified) is the direct examination. The retaining attorney will ask the expert questions designed to bring out such matters as the evidence reviewed, the bases for opinions, and the opinions derived. The opposing side then gets to conduct a cross examination, during which the opposing attorney may ask questions designed to cast doubt on the expert’s credibility, methods, opinions, and profession. It is important to note that on direct examination, the retaining attorney may not ask leading questions (i.e., questions that imply or contain the answer), whereas such practice is allowed during cross-examination, which can allow for a more confrontational approach by the opposition attorney. Cross-examination may be followed by redirect, during which the retaining attorney attempts to ‘rehabilitate’ any problems caused during cross-examination by asking questions that may clarify or reinforce the expert’s testimony and credibility.

4. The Admissibility Of Expert Testimony

Any discussion of the admissibility of expert testimony, including that involving mental health experts, requires coverage of a recent landmark decision. In the case of Daubert, vs. Merrell Dow Pharmaceuticals, Inc. (1993) the United States Supreme Court established a set of standards that now govern the admissibility of expert testimony in the Federal court system. Many states have also fully or partially adopted the Daubert standards. Prior to Daubert, two standards of admissibility governed the admissibility of expert testimony, Frye and the Federal Rules of Evidence (1974, 1984) which sometimes seemed to contradict one another and assigned different functions to the judge.

In Frye vs. United States (1923), the defendant in a criminal case sought to have an expert provide testimony that, based on the experimental use of blood pressure measurements, the defendant was truthful in his assertion of innocence. The court ruled the expert’s testimony inadmissible because it was not based on techniques that were generally accepted within the relevant scientific community. The ‘general acceptance’ standard set down by Frye created certain problems because it combines both excessive conservatism in relation to novel but valid techniques with excessive acceptance of techniques that, while invalid or at least highly questionable or insufficiently tested, are endorsed by the majority (or at least a ‘respected minority’) of practitioners of a given field. When following Frye, the judge does not so much decide the admissibility of testimony based on its seeming scientific merits, but defers to the judgment of the scientific community by considering the degree to which the methodology underlying that testimony or conclusions is accepted. For example, if a review of the scientific literature seems to raise very serious doubts about a method or is generally negative, but the method is still embraced by a substantial proportion of practitioners, then the latter consideration rather than the former should be decisive under Frye.

It is easy to see how this standard can create tremendous problems when considering expert psychological testimony. There may be a wide gulf between the practices of psychologists and the scientific data on which they base (or fail to base) their methods and opinions. In many areas of interest to the courts, the scientific research may have yielded mixed results, or be lacking altogether, and yet, for a variety of reasons, practitioners may still act in a manner that belies that evidence or engage in activities in the absence of sound science. Even in the circumstance where a sound base of scientific knowledge does exist, it may not pertain directly to the specific questions at issue.

In the Daubert decision, the Supreme Court stated explicitly that the judges’ role as gatekeeper under the Federal Rules of Evidence superceded the ‘general acceptance’ criteria specified in Frye, although it did not dismiss all elements of Frye entirely. Admissibility was to be determined by the judge’s evaluation of the scientific merits of an expert’s methodology. In addition, the text of the decision set forth a list of criteria upon which such decisions could be based, which are not exhaustive nor given in any hierarchical order or priority. These criteria included:

(a) General acceptance in the relevant scientific field (as per Frye).

(b) The degree to which the theoretical basis of the testimony is testable and falsifiable.

(c) Publication of peer-reviewed literature.

(d) The known error rate where diagnostic or predictive tasks are involved.

Daubert touched off a firestorm of debate in the legal and scientific communities, some of which focused on the overall effect that it would have on the quality of the expert advice the courts would allow into evidence. On the one hand, Daubert liberalizes the standards as an expert may present evidence that is not necessarily endorsed by the broader scientific community. This serves to widen the range of potential topics for consideration by the court, and recognizes that science is constantly evolving. On the other hand, by requiring judges to critically evaluate the scientific status of testimony, Daubert has the potential to function as a barrier to weak or junk science entering into the legal process. Within psychology, the response to Daubert has involved, to date, articles predicting the possible effects of the ruling, proscriptions, and recommendations for the psychologist working within the framework provided by Daubert, and debate about the degree different techniques, diagnoses, and procedures meet (or fail to meet) the Daubert standard.

There have been dozens of cases in which the admissibility of forensic psychology and social science evidence has been decided under the Daubert standard, including both civil and criminal cases. The types of evidence proffered to date have included (broadly) testimony on psychological syndromes; behavior profiles and diagnostic techniques related to sexual abuse victimization; eyewitness identification; theory and experimental data related to civil rights and discrimination; the prediction of dangerousness and causal or mitigating factors in violent behavior; issues of mental state or condition; and ‘truth-telling’ techniques. In a substantial percentage of these cases, the testimony offered has been rejected either in whole or in part.

The bases for rejecting a psychologist’s testimony in part or fully have included a lack of relevant scientific research, inconclusive or negative findings in the research literature, failure to adhere to well-established methods or procedures, and inadequate credentials. A Daubert challenge to an expert’s status can be raised at different points during litigation de- pending on a series of factors. For example, a hearing may be held well in advance of trial or at the time of trial.

Although some areas of psychological research are more vulnerable to a Daubert challenge than others, the frequency with which testimony has been judged inadmissible is of concern to forensic psychologists, attorneys, and the parties who are involved in litigation where the expert testimony of psychologists is of significance or may be absolutely critical to the case. Legitimate claims (and the defenses against illegitimate ones) based on psychological testimony are substantially, and perhaps fatally, undermined when psychological experts fail to practice in a manner consistent with good science and their testimony is excluded.

A problem that arises under Daubert is that an expert witness possesses knowledge or expertise that the judge often does not. Judges may lack the training that is required to fully evaluate the expert’s field or scientific methodology in general. Thus, although it seems an important advance to require experts to back their opinions with more than the assertion that ‘I am the expert, and therefore my opinion is valid,’ the pragmatics for achieving the desired scrutiny still leave certain gaps. Further, because the list of considerations is not complete nor arranged in order of priority, the standards are clearest in the almost self-evident situation in which all scientific indicators are positive or negative. It is in the more ambiguous situation in which indicators are inconsistent and yet scientific status may still be strong (or weak) overall that more guidance is needed and decisions to date have sometimes been rather inconsistent. For further references and review of the effect of Daubert on the admissibility of psychological evidence, see Schuman and Sales (1999) and Wettstein et al. (1995).

5. Recent Trends And Developments

In recent years there has been significant professionalization in the field of psychology and law, which has included the formation of numerous professional organizations and the publication of various books, professional journals, ethical standards, training guidelines, and other scholarly materials related to the theory and practice of forensic behavioral science. Training programs and internships with a forensic component are increasingly available and a number of programs offering joint law and psychology degrees have been established. With this specialization has come a growing body of research that seeks to directly address legal issues (e.g., the prediction of violence or detection of malingering) and various aspects of human behavior within the courtroom (e.g., factors influencing jury decisions or the credibility of eyewitness testimony).

Although standards vary in different jurisdictions, there appears to be an increased acknowledgment of the gap between the level of certainty required by the court and the state of the art within many areas of psychology. Stimulated in part by calls for increased accountability (e.g., Ziskin 1970, Faust et al. 1991), and mandated by rulings such as Daubert, experts are now frequently required to demonstrate that there is a scientific basis for their methods, predictions, and conclusions. The pronouncement ‘We know from clinical experience that …’ is no longer accepted in many legal arenas as an adequate justification for expert status or for the particular aspects of expert testimony.

The rules governing the use of expert witnesses are subject to change at any time in response to new precedent or legislation, but given the above trends, it seems reasonable to hope that the above efforts will continue to strengthen the scientific bases that will allow psychologists to increasingly provide true assistance to the trier of fact, and aid in the fair and just resolution of legal cases.

Bibliography:

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