"Experts" appear in the modern American courtroom on the jury as well as in the witness box, posing a dilemma for the legal system by offering a potentially valuable resource and an uncontrolled source of influence. Courts give ambiguous guidance to jurors on how they should handle their expertise in the deliberation room. On the one hand, jurors are told that they should "decide what the facts are from the evidence presented here in court." By direct implication, then, jurors should not use outside information to evaluate the evidence. Jurors are also told, however, that they should "consider all of the evidence in the light of reason, common sense, and experience." And indeed, all decision makers, including jurors, are unavoidably influenced by their own backgrounds and experiences as they evaluate evidence and reach decisions.
In this Article we examine the actual and desirable behavior during deliberations of jurors with specialized expertise. We draw on three sources to assess how often citizens with specialized knowledge serve as jurors, how they behave when they do, and how legal professionals view the appropriateness of the contributions juror experts may make. Our sources include: (1) a survey of 167 experienced trial attorneys who reported on their recent trial experience with juror "experts"; (2) the actual deliberations of jurors in fifty civil trials from the Arizona Jury Project, which revealed how real jurors use their expertise in the jury room; and (3) a survey of 128 judges and attorneys who evaluated examples of "expert" juror behavior. Some scholars suggest that jurors with specialized expertise should be excused for cause. In light of our findings, we conclude that such drastic intervention is unwarranted and would inappropriately undermine the increasing heterogeneity on the jury that the elimination of occupational exemptions has worked to promote. We instead advocate a tempered response to the growing presence of juror expertise in the jury room.
TABLE OF CONTENTS INTRODUCTION I. STANDARD LEGAL CONTROLS ON SPECIALIZED JUROR KNOWLEDGE II. SPECIALIZED JUROR KNOWLEDGE IN THE MODERN Jury Trial A. Trial Attorney Survey B. The Arizona Jury Project 1. The Background of the Project 2. Selection of Jurors and Cases 3. Data Collection and the Final Sample 4. The Data a. The Trials b. Data from the Deliberations c. Post-trial Questionnaires 5. Jurors and Their Expertise III. HOW SHOULD JURORS HANDLE SPECIALIZED KNOWLEDGE? IV. WHAT (IF ANYTHING) SHOULD BE DONE ABOUT JUROR-EXPERTS? "[W]hile the jury may leaven its deliberations with its wisdom and experience, in doing so it must not bring extra facts into the jury room."
Judge Irving Goldberg (1)
Juries have become increasingly representative over time. No longer are juries the exclusive domain of white male property-owners deemed (by a court official) to be of good character. (2) Although the modern jury is not fully representative of the community, changes in eligibility requirements and methods of summoning jurors have made the modern jury far more heterogeneous than it has ever been. (1) Much of the recent push for juries representing a cross-section of the community has focused on removing racial and gender restrictions, albeit with mixed success, (4) but jury reform efforts have also led to the elimination of most occupational exemptions. (5) If jury service is viewed as a responsibility and opportunity that all able-bodied citizens should share, it is hard to justify excluding citizens from service based on occupation. Consistent with this view, jurors with specialized occupational expertise are now eligible to appear on the jury as well as in the witness box and, as the data we present reveal, they are appearing not only in jury venires but also on juries. (6) These jurors create a dilemma for the legal system, offering a potentially valuable resource and an uncontrolled source of influence.
Other changes in the trial intersect with the potential for specialized juror expertise. Evidence in the modern American jury trial increasingly includes scientific, technical, or other specialized knowledge. (7) The trial court plays the role of gatekeeper when a party proposes to have an expert testify, vetting the expert's credentials and the nature of the testimony being offered. (8) Experts permitted to appear as witnesses answer only legally relevant questions posed in open court and are subject to cross-examination by opposing counsel. (9) Jurors often receive a special instruction on how to evaluate expert testimony. (10) Yet not all nonlegal expertise that enters the jury room may come from the witness stand. Nor may all legal expertise come from the judge. Until recently, most states excluded from jury service individuals in particular occupations (e.g., physicians, lawyers, clergy) (11) but that has changed. (12) In recent years, states have reduced their occupational exemptions; over half of all states now have no automatic exemptions. (13) The result is that venires are more likely to include prospective jurors who have specialized expertise.
According to conventional wisdom, even if jurors with relevant occupational expertise appear in the venire, they are likely to be removed. If the judge does not excuse such jurors, the attorneys will use peremptory challenges during jury selection to remove all jurors whose backgrounds indicate particular expertise relevant to the case. Nurses will be excused from cases involving medical claims; engineers will be removed by peremptory challenge if one of the parties plans to introduce technical engineering testimony; attorneys will inevitably be excused. In fact, this picture turns out to be inaccurate. As we show in two studies reported below, the modern American jury frequently includes jurors with relevant occupational expertise. Moreover, some successful attorneys with extensive trial experience may actually welcome these embedded experts to serve on the juries they select.
Jurors typically receive no guidance on how their own expertise, as opposed to witness expertise, should be handled. On the one hand, jurors are told, "You will decide what the facts are from the evidence presented here in court." (14) By direct implication, jurors should not use outside information to evaluate the evidence. Jurors are also told, however, that they should "[cjonsider all of the evidence in the light of reason, common sense, and experience." (15)
Indeed, all decision makers, including jurors, are unavoidably influenced by their own backgrounds and experiences as they evaluate evidence and reach decisions. (16) Moreover, one valuable characteristic of the jury is the mixture of experiences that its members bring to the task of resolving conflicting and uncertain claims. (17) What is less clear is the role that these embedded "juror-experts" (18) should play in deliberations and how other jurors should consider the purported knowledge of these jurors who come to the trial with specialized expertise. In this Article we explore both the desirable range of behavior by jurors with specialized expertise and the actual behavior of jurors with specialized expertise during jury deliberations. Based on this investigation, we consider the appropriate response of the legal system to juror expertise.
We begin in Part I by reviewing the variety of approaches courts take when they learn that jurors have specialized knowledge that may impact jury deliberations. In Part II we present two studies that reveal how pervasive specialized juror knowledge has become in the modern jury trial and provide evidence tracking the behavior of these juror-experts during deliberations. In Part III we consider what behavior is desirable and attainable when embedded experts are seated on a jury. Finally, in Part IV we suggest an approach to juror-experts that will avoid overreaction to a useful and democratic development in the jury system.
STANDARD LEGAL CONTROLS ON SPECIALIZED JUROR KNOWLEDGE
We begin by examining how courts typically delineate the boundaries of appropriate juror behavior when a juror possesses knowledge based on information gleaned outside the trial. In evaluating court responses, it is important to recognize that courts are reluctant to entertain any challenge to the verdict of a jury based on what has occurred during jury deliberations. (19) The rationales are that deliberations should be free of constraint and insulated from outside pressure and that the stability and finality of verdicts should be protected. (20) Nonetheless, when reliable evidence emerges that jurors have sought information from external sources during the trial--whether from people, newspapers, the Internet, or dictionaries--trial courts generally view that juror behavior as misconduct and may order a new trial. Similarly, if a juror inspects the scene of an accident or the crime at issue in the case, courts agree that the juror has not fulfilled the obligation to draw solely on the evidence presented at trial. (21) Although this behavior reflects juror efforts to understand the evidence and to reach well-informed verdicts, these actions are out of bounds and can be understood as explicit violations of the court's instructions to the jury. Reflecting this prohibition on gathering extra-trial information, Federal Rule of Evidence 606(b) recognizes evidence of "extraneous prejudicial information [that] was improperly brought to the jury's attention" as a basis for inquiry into the validity of a verdict. (22) This inquiry is an exception to the usual protection extended to jury deliberations that limits the use of juror testimony to impeach a jury verdict. (23)
When the specialized knowledge injected into deliberations comes from the personal experience of a juror obtained before rather than during trial, courts vary substantially in their response. Texas, for example, construes outside influence narrowly, requiring...