Scientific and Technical Evidence in the Courtroom
During its first day and into the morning session of the second day, the Panel reviewed three Supreme Court cases dealing with the admissibility of expert evidence and the implications of these cases for judges, juries, and expert witnesses. Complicated questions of fact increasingly demand scientific and technical judgments by jurists, juries, and lawyers, who are usually not well prepared by education or experience to make such decisions. These deliberations are summarized below.
THE SUPREME COURT TRILOGY
The law of expert evidence has changed substantially in the past decade as the result of three Supreme Court decisions. In 1993, the Frye rule3 for determining admissibility of expert testimony gave way after nearly 70 years to the Daubert criterion of scientific reasoning and methodology. Frye looked to the scientific community for guidance, allowing judges to admit testimony if the theory underlying the expert's opinion had “gained general acceptance in the particular field in which it belongs.”
The first case in the trilogy, Daubert v. Merrell Dow Pharmaceuticals, Inc., is a 1993 case involving birth defects alleged to have resulted from a mother's use of Bendectin, a morning sickness remedy. In this case, the Supreme Court established a test for the admissibility of scientific evi-
dence that required that the testimony not only to be relevant to the facts of the case, but also to be reliable. The new admissibility test requires judicial assessment of “whether the reasoning or methodology underlying the testimony is scientifically valid and of whether the reasoning or methodology properly can be applied to the facts in issue.” To meet the reliability test, the testimony must be the result of scientific reasoning and methodology evidenced by four factors:
whether the theory can be tested;
whether the theory has been published in a peer-review publication;
whether there exists known or potential error rates; and
whether there are standards for controlling the technique's execution.
In specifying these factors, the Supreme Court gave the trial judge responsibility for assessing the soundness of the scientific information and reasoning that an expert witness presents in court. In so doing, the Supreme Court assigned the role of “gatekeeper” to the trial judge, requiring that the judge screen expert testimony to determine both its relevance and reliability while respecting the role of the jury to resolve disputed factual issues.
The second case in the trilogy, General Electric v. Joiner, a toxic tort case in which the plaintiff alleged that his lung cancer was a result of his exposure to polychlorinated biphenyls (PCBs), is a case in which the trial judge applied the Daubert criteria, excluded the testimony, and granted summary judgment. The appellate court reversed and set the stage for the Supreme Court's consideration. In Joiner, the Supreme Court held that the appellate courts, when reviewing a lower court's decision admitting or excluding expert testimony, must use an abuse of discretion standard that requires deference to the trial judge's ruling. The Supreme Court then went further, reviewing the evidence and finding that the trial judge had not abused her discretion in excluding testimony, since the expert failed to adequately relate his testimony in the case to the scientific studies on which he had relied.
The third case in the trilogy, Kumho Tire Co. v. Carmichael, is a product liability case in which the plaintiff claimed that a tire on his vehicle blew out as a result of a defect. In this 1999 case, the Supreme Court extended the trial judge's gatekeeper obligation to all expert testimony, not just purely scientific testimony. The Court “concluded that Daubert's general holding—setting forth the trial judge's general ‘gatekeeping' obligation— applies not only to testimony based on ‘scientific' knowledge, but also to testimony based on ‘technical' and ‘other specialized' knowledge.” The Court declared that the expert in the courtroom must employ “the same
level of intellectual rigor that characterizes the practice of an expert in the relevant field.”4
In response to the Supreme Court's trilogy on expert proof, Rule 702 of the Federal Rules of Evidence (“Testimony by Experts”) was amended in 2000. The rule now states that [additions underscored], “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 if (1) the testimony is based upon sufficient 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.”
Implications of the Trilogy for Judges, Juries, and Experts
As a result of these decisions and the amended rules, the STL Panel was interested in knowing how the legal system is responding, what the implications of these decisions are for the key players in litigation (judge, juror, and expert) and what mechanisms would help these players fulfill their responsibilities in court. The STL Panel discussed a number of mechanisms to help courts deal more effectively with scientific and technical evidence. Many of these approaches, such as court-appointed experts, are controversial and most are fraught with complexities. Existing and proposed remedies are discussed below.
It was noted that judges have little spare time for in-depth study of science or engineering. Nonetheless, in today's courtroom, they need intensive, focused information and educational tools to help them understand the scientific and technical basis of expert testimony.
Special Masters. Judges currently may appoint special masters in certain exceptional cases. These officials are generally experts on the law, but sometimes they have specialized scientific or technical expertise. The powers and duties of the special master vary widely. They may include supervising the discovery of evidence, preparing reports for consideration by the judge or jury, or overseeing expert depositions.
Court-Appointed Witnesses. Under Rule 706 of the Federal Rules of Evidence, a judge may appoint an expert witness, or even a panel of witnesses, of his own choosing. Such a witness may be asked to report on a particular scientific or technical issue for the case, and is then deposed by both parties as part of the discovery process. The federal judge overseeing most of the federal cases involving silicone gel breast implants, for example, appointed a four-member scientific panel to prepare a report on the scientific basis of competing claims made by the parties. The Panel was appointed with the approval of both the plaintiffs' and the defendants' counsel. Its costs were defrayed by the Administrative Office. Over the course of 2 years, the Panel reviewed relevant scientific literature, produced a report, and was deposed. Special counsel were retained to represent the Panel. (See Hulka et al., 2000.)
One experiment in making independent experts more conveniently available to judges is the recently launched Court Appointed Scientific Experts (CASE) demonstration project of the Scientific Freedom, Responsibility and Law Program of the AAAS. As part of the project, judges wishing to appoint experts may call on CASE staff for help in identifying highly qualified scientists and engineers to serve as experts to the courts, rather than to the parties in litigation. CASE staff use several methods to identify suitable experts, including requesting help from professional and scientific societies and institutions. A CASE Recruitment and Screening Panel composed of respected scientists and engineers screen and recruit experts. Subcommittees will prepare educational and resource materials for courts and for the scientists and engineers identified as prospective experts, and will advise on such matters as conflicts of interest. An advisory committee (chaired by a federal appeals court judge) oversees the project. The Federal Judicial Center (the research and education arm of the federal judiciary) will evaluate CASE.
The Private Adjudication Center, Inc., of Duke University School of Law also maintains a registry of independent scientific and technical experts who are willing to provide advice to courts or serve as court-appointed experts. In addition, the Federal Judicial Center offers a series of programs to acquaint judges with scientific principles and evidentiary standards used to evaluate the admissibility of technical proof.
Technical Advisors. Some suggested that judges should have established sources of technical and scientific information, who could be called upon not to serve as witnesses, but as tutors. A roster of such individuals who could explain difficult technical aspects of cases, for example, those that might involve advanced statistics or the chemistry of gene expression, could provide assistance to judges.
Video, Print, or Online Summaries. The Internet provides new opportunities for “learning on demand” or “just-in-time learning” that could provide judges with access to scientific and engineering materials over the course of a case. In theory, a judge might also be able to visit an Internet site covering a scientific or engineering topic, and then navigate by hyperlink through a great mass of authoritative information.
In practice, however, developing such materials is not a trivial task. Such materials must be prepared and reviewed by both scientific and legal communities to ensure that they are not only accurate and represent the consensus of the field, but are without bias. Sources able to provide funding for such materials are not readily identifiable.
Short Courses. A number of academic institutions host brief summer sessions to help judges understand the role of science and technology in the courtroom. These include the Program in Judging Science of Duke University's Private Adjudication Center; the University of Virginia's Graduate Program for Judges; and various courses at the National Judicial College. However, attendance at these sessions tends to be sparse, due to competing demands on judges' time and the scarcity of funds in court budgets.
Specialized Courts. Specialized courts have been proposed as a way to help courts deal more effectively with scientific and technical evidence (see, for example, Kantrowitz, 1967). However, today federal judges are normally assigned cases by lot, not on their expertise. Some particularly complex or broadly significant cases may be aggregated regionally or nationally for limited purposes as authorized by statute, as occurred with the federal cases involving silicone gel breast implants.
Long-Term Independent Research Programs and Periodic Reviews. One promising approach could be to conduct a series of long-term studies of scientific topics of potential regulatory interest both to establish a basis for consensus and at the same time give judges forewarning of emerging scientific and technical issues. These types of studies have been used to reduce disputes about the facts in contentious regulatory arenas including the health effects of air pollution. For areas of science in which a long-term view is possible, this approach might reduce some of the inevitable conflicts over regulation. However, this approach is less applicable to the fast-moving fields of science and technology, such as those issues arising in the increasing number of intellectual property cases heard by federal courts.
The right to a trial by a jury is guaranteed by the Constitution. The challenges of presenting scientific and technical information to jurors are at least as great, if not greater, as those of helping judges understand such material. The STL Panel considered a number of approaches, discussed below, that could improve the jury's understanding and assessment of scientific and technical testimony.
Providing Scientific and Technical Information. Background materials explaining the scientific process and addressing specific scientific or technical questions could be prepared to help juries understand and assess the pertinent facts at issue in a particular case. These materials would have to be developed in a “just-in-time” manner.
Developing Model Jury Instructions. Jury instructions are critical sources of information on the law and the rules of evidence. Many jurors, some judges say, are swayed unduly by the aura of certainty that scientists and engineers may present in court. Judges' instructions to juries could be formulated to help jurors better evaluate expert testimony and to focus on the reasoning underlying the expert testimony rather than traditional credibility assessments. A model set of instructions might, for example, be developed to aid jurors' understanding of probability, risk, or a particular scientific or technical question at issue.
Several STL Panelists noted that the Daubert and Kumho decisions shine a spotlight on the methodology and reasoning of the expert witness. This scrutiny itself may force an improvement in the quality of testimony that experts offer. The STL Panel discussed several other ways to improve expert testimony.
Preparing Tutorials for Expert Witnesses. Many scientists and engineers who are required to testify in court are unprepared for the experience. Several different kinds of guides for experts might be useful including:
1. Ways to present information that will be useful to juries and judges.
2. Tutorials on the legal processes of discovery and testimony.
3. Tutorials on the legal demands for confidentiality and how these demands may constrain one's analysis.
Developing Ethical Standards for Expert Witnesses. While experts who appear in court represent the interests of particular parties, it is not clear from a legal perspective to whom experts owe ethical obligations and whether they are governed by the ethical standards that apply to lawyers, to their professions, or to something more. Scientific and technical associations could find it useful to develop or support strong codes of ethics for members who testify as experts. Some professional associations, such as the American Psychological Association and the American College of Occupational and Environmental Medicine have developed standards for conduct in the courtroom.