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American University Law Review
October, 1995




Since the U.S. Supreme Court's decision two years ago in Daubert v. Merrell Dow Pharmaceuticals, Inc.,1 which clarified the standards for admitting new scientific evidence,2 scholars have commented extensively on the expanded use of expert evidence in the courts. In particular, commentary has focused on the fields of mass tort litigation3 and criminal law.4 Less noticed, but no less dramatic, is the parallel increase in the use of expert evidence in federal civil rights litigation.5 Beginning with the landmark case of Brown v. Board of Education,6 this trend is reflected in the diverse issues involving expert proof, often novel in nature, which have regularly appeared in the Supreme Court's civil rights decisions.

In the 1970s, for example, the Court pondered medical evidence in civil rights cases that presented such diverse issues as the question of when human life begins,7 the ability of a pregnant teacher to continue to work,8 and the suitability of methadone users for employment as public transit workers.9 The Supreme Court also considered penological evidence supporting a state's refusal to hire women as correctional officers.10 Frequently, the Court's civil rights opinions grappled with various types of statistical evidence, including a validation study demonstrating that a hiring exam for police was effective in selecting recruits who could succeed in the police training program,11 calculations disproving racial disparity in hiring teachers in public schools,12 data indicating the rate of admission of women to an institution of higher learning,13 statistics depicting the results of a racial preference in medical school admissions,14 and demographic data relating to racial segregation in public schools.15 In election rights cases decided during the 1970s, the Supreme Court considered statistics on minority voter registration in jurisdictions with literacy tests,16 the magnitude of campaign contributions restricted by federal law,17 and, on several occasions, the equality of legislative apportionments.18

Cases decided in the 1980s revisited issues relating to statistical evidence of racial discrimination in the promotion of employees by the U.S. Postal Service19 and in the pay rates of bank employees20 and state and local agricultural workers.21 Other cases considered medical evidence on the physiological and psychological qualifications for employment of flight engineers over age sixty,22 social psychological testimony regarding sex stereotyping in evaluations for admission to partnership in an accounting firm,23 and testimony from a variety of experts on whether creationism, which asserts that the Biblical account of the beginning of the universe is supported by scientific inquiry, could be characterized properly as science so that teaching it would not violate the Establishment Clause of the First Amendment.24

In recent Terms, medical evidence has played a central role in the Court's civil rights cases on an array of difficult issues, including the involuntary administration of antipsychotic drugs to prisoners,25 the withholding of artificial means to preserve the life of a terminally ill individual,26 the appropriateness of excluding discussion of abortion during government-sponsored family planning counseling,27 and, for purposes of a due process challenge to commitment procedures, thediagnosis and treatment of mentally retarded persons.28 While considering cases under the Eighth Amendment,29 the Court encountered expert evidence that executions by administering cyanide gas30 and by hanging31 were unnecessarily prolonged and torturous. Similarly, the Court remanded to the district court a prisoner's challenge to conditions of confinement in order to evaluate expert evidence of injury to health based on exposure to environmental tobacco smoke.32 Addressing the constitutionality of restrictions on access to abortions, the Court also scrutinized expert testimony on the effects of spousal notification requirements, informed consent, and a twentyfour hour waiting period.33

The proliferation of new types of expert evidence in federal civil rights cases has not gone unchallenged. Disputes regarding the admissibility of expert evidence are now routine. To date, approximately one in every eight federal cases citing to the Supreme Court's decision in Daubert is a civil rights action.34 The frequency with which issues of expert evidence arise in civil rights cases is unlikely to diminish for a number of reasons. First, the technocratic nature of our society, including its increasing reliance on technological means to regulate human behavior in areas such as employment and law enforcement,35 generates many civil rights cases. Second, case lawand statutes have recognized new claims, such as exposure to unreasonable health risk from environmental tobacco smoke or discrimination due to disability, which ordinarily require consideration of expert evidence.36 Third, the economic value of most categories of employment discrimination cases arising after the passage of the Civil Rights Act of 1991 (1991 Act)37 has increased significantly and will support additional investment in expert proof for this common type of civil rights litigation. Finally, the 1991 Act has made available an award of expert fees to the prevailing party in certain civil rights cases.38

This Article addresses evidentiary and procedural issues which arise when parties offer novel39 expert evidence in federal civil rights litigation. Part I chronicles the introduction of Professor Kenneth Clark's controversial tests using dolls representing different races in the landmark case of Brown v. Board of Education. Part II examines the traditional standard for the reliability of novel scientific proof set forth in Frye v. United States,40 the development of alternative standards after the adoption of Federal Rule of Evidence 702 in 1975, and the assessment of the reliability of expert evidence in federal civil rights cases decided prior to Daubert. Part III analyzes the Supreme Court's decision in Daubert, which attempted to resolve the conflicting authorities governing the reliability of expert evidence and directed the district courts to serve as gatekeepers by screening the relevance and reliability of purportedly scientific evidence under the Federal Rules of Evidence.41 Part IV explores factors that influence a district court in its role as gatekeeper, including the court's philosophy with respect to this duty, the scope of the court's discretion, and the court’s duty to exercise this discretion. Part IV suggests that because civil rights actions assert basic personal rights42 and often raise broad social justice issues, district courts should incline toward admitting novel expert evidence to facilitate the resolution of these cases on their merits. This section also considers the relationship between the procedural context, including issues arising under the comprehensive amendments to the Federal Rules of Civil Procedure effective December 1, 1993,43 and the court's exercise of discretion. In addition, Part IV discusses the need to tailor the gatekeeping function to the type of evidence proffered. The section suggests that the courts adopt different approaches to assess the scientific, technical, and other specialized knowledge which may be admitted as expert evidence. Part V examines elements of the gatekeeping determinations exhibited in recent civil rights cases. Finally, Part VI makes several recommendations for addressing novel expert evidence in civil rights cases.

I. In the Beginning, Brown v. Board of Education

The other significant point in this case is that one witness, Dr. Kenneth Clark, examined the appellants in this very case and found that they were injured as a result of this segregation.44 . . . .[I]n this case, we have the positive testimony from Dr.Clark that the humiliation that these children have been going through is the type of injury to the minds that will be permanent as long as they are in segregated schools, not theoretical injury, but actual injury.45
In the consolidated cases known as Brown v. Board of Education,46 federal civil rights litigation came of age. The case, which heralded great change in constitutional law, public schools, and the fabric of society,47 also introduced the civil rights field to the debate regarding the use of novel forms of scientific proof as evidence.

At trial in Brown's consolidated case Briggs v. Elliott,48 the National Association for the Advancement of Colored People (NAACP) presented dramatic testimony by Professor Kenneth Clark of the City College of New York.49 Professor Clark performed innovative psychological tests utilizing dolls to identify harms inflicted on the plaintiff children due to segregation.50 Professor Clark described the tests and his conclusion in response to questioning by Robert Carter of the NAACP:
A. I made these tests on Thursday and Friday of this past week at your request, and I presented it to children in the Scott's Branch Elementary school, concentrating particularly on the elementary group. I used these methods which I told you about--the Negro and White dolls--which were identical in every respect save skin color. And, I presented them with a sheet of paper on which there were these drawings of dolls, and I asked them to show me the doll--May I read from these notes?
JUDGE WARING: You may refresh your recollection.
THE WITNESS: Thank you. I presented these dolls to them and I asked them the following questions in the following order: "Show me the doll that you like best or that you'd like to play with," "Show me the doll that is the 'nice' doll," "Show me the doll that looks 'bad'," and then the following questions also: "Give me the doll that looks like a white child," "Give me the doll that looks like a colored child," "Give me the doll that looks like a Negro child," and "Give me the doll that looks like you."
By Mr. Carter:
Q. "Like you?"
A. "Like you." That was the final question, and you can see why. I wanted to get the child's free expression of his opinions and feelings before I had him identified with one of these two dolls. I found that of the children between the ages of six and nine whom I tested, which were a total of sixteen in number, that ten of those children chose the white doll as their preference; the doll which they liked best. Ten of them also considered the white doll a "Nice" doll. And, I think you have to keep in mind that these two dolls are absolutely identical in every respect except skin color. Eleven of these sixteen children chose the brown doll as the doll which looked "bad." This is consistent with previous results which we have obtained testing over three hundred children, and we interpret it to mean that the Negro child accepts as early as six, seven or eight the negative stereotypes about his own group. . . .
Q. Well, as a result of your tests, what conclusions have you reached, Mr. Clark, with respect to the infant plaintiffs involved in this case?
A. The conclusion which I was forced to reach was that these children in Clarendon County, like other human beings who are subjected to an obviously inferior status in the society in which they live, have been definitely harmed in the development of their personalities; that the signs of instability in their personalities are clear, and I think that every psychologist would accept and interpret these signs as such.
Q. Is that the type of injury which in your opinion would be enduring or lasting?
A. I think it is the kind of injury which would be as enduring or lasting as the situation endured, changing only in its form and in the way it manifests itself.
MR. CARTER: Thank you. Your witness.51

Professor Clark's testimony, while founded on scientific principle, carried great emotional power, and therefore caused vigorous debate among the litigants and scholars as to its import.52 NAACP counsel Thurgood Marshall, arguing on behalf of plaintiff schoolchildren, asserted the broadest inference that could be drawn from results of these tests: they proved actual harm done by segregated schools.53 Thus, minority schools violated the Fourteenth Amendment54 because they could not satisfy the separate but equal standard announced by the Court in Plessy v. Ferguson.55 Other NAACP lawyers, like many civil rights practitioners who would follow in their footsteps, struggled with the meaning of the novel scientific evidence that they were attempting to develop. One historian subsequently reported that Professor Clark's tests using the dolls were "the source of considerable derision" among plaintiffs' attorneys.56 William Coleman, a former clerk for Supreme Court Justice Felix Frankfurter, acknowledged, "Of all the debunkers, I was the most debunking. . . . I thought it was a joke."57 Professor Clark, who also served as principal advisor on the expert testimony for the school desegregation cases,58 was well aware of the controversy. He recalled:
Thurgood [Marshall] kept his options open. He played the role of conductor beautifully. It was clear that Bob Carter was the most persistent, consistent advocate of the involvement of the social scientists at the trial level. Bob was way out on the limb, pretty much by himself. Most of the other lawyers felt this approach was, at best, a luxury and irrelevant. Thurgood Marshall didn't tip his hand, except that he did let Bob and me go ahead with the dolls.59
John W. Davis argued on behalf of the defendant school officials.60 Davis chose to attempt to undermine the doll tests' stature as scientific evidence by invoking a sarcastic style of argument. He pointed out that Professor Clark purported "to speak as an expert and informed investigator."61 From an "intensive investigation" and "thoroughly scientific test," Professor Clark reached the "sound conclusion" that the plaintiffs suffered harm in their development.62 Calling the result "sad," Davis declaimed that the court was "invited to accept it as a scientific conclusion."63 In concluding, however, Davis attempted to turn Professor Clark's published research64 in the defendant’s favor by pointing out that a greater percentage of black children in northern schools preferred the white doll, thought the white doll was nice, and thought the black doll was bad.65 He declared, "Now these latter scientific tests were conducted in nonsegregating states, and with those results compared, what becomes of the blasting influence of segregation to which Dr. Clark so eloquently testifies."66

The Court ordered reargument of the cases67 and did not issue its opinion until May 17, 1954.68 Holding that racial segregation of children in public schools was a per se violation of the Fourteenth Amendment, the Court found that segregation "generates a feeling of inferiority as to their status in the community that may affect the childrens' hearts and minds in a way unlikely ever to be undone."69 Noting the consistent findings in the Kansas70 and Delaware71 decisions that segregated schools injured the plaintiffs and denied them equal educational opportunities,72 the Court concluded that "[w]hatever may have been the extent of psychological knowledge atthe time of Plessy v. Ferguson, this finding is amply supported by modern authority."73

The "modern authority" cited by the Court suggested the Justices' ambivalence regarding the evidence of Professor Clark. While the Court lists Professor Clark first among the sources, the reference is to a monologue summarizing his research, including his early doll tests, which he delivered at the Midcentury White House Conference on Children and Youth in 1950.74 The Court, however, makes no mention of his testimony regarding the testing of the Briggs plaintiffs, citing only other studies and books.75 Although the Court was clearly persuaded that "[s]eparate educationalfacilities are inherently unequal,"76 its opinion relies primarily on this broad principle of equality rather than the novel scientific evidence introduced by the NAACP on behalf of the plaintiffs in Briggs.77

Notwithstanding the Court's omission of any explicit assessment of the reliability of Professor Clark's testimony as scientific evidence of harm from segregated schools, commentators debated the validity of Professor Clark's methodology and conclusions for many years after the Brown arguments. A student note published after the first round of oral arguments opined that the doll test results could not be traced "with certainty" to school segregation because a NorthSouth breakdown of the results did not establish any statistically significant difference.78 Moreover, analysis of Professor Clark’s data by age indicated that the children were already aware of race and the values attached to it by the time they entered school.79 The note stated that psychologists "had not yet gone far enough" to provide the necessary support for a favorable ruling under the separate but equal doctrine.80

Legal scholar Edmond Cahn asserted additional criticisms.81 Specifically, Cahn claimed that Professor Clark offered no proof of the adequacy of his sample, no standards for the interpretation of responses, no testimony that the test purported to demonstrate the effects of school segregation, no inquiry to address habituation with dolls, and no control tests of white children.82 Cahn cautioned that the use of technical language should not convert armchair psychology into science and called for the utmost rigor in assessing evidence drawn from social psychology, a discipline which was then in its formative stages.83 Other critics suggested that Professor Clark did not take the test results seriously; otherwise he would have testified that desegregation was harmful.84 The critics faulted the absence of control tests, which might have indicated that the results were explainable by the symbolism associated with the colors.85

Professor Clark concluded the debate with a reply published at the close of the decade.86 He wrote that while social scientists had been studying the effects of prejudice and segregation for about fifteen years at the time of Brown, he and others had advised counsel for the plaintiffs that it was not possible, based on the then available studies, to present evidence that public school segregation, in itself, damaged the personalities of the plaintiffs.87 The difficulty, according to Professor Clark, was that segregation had not been isolated as a "variable from the total social complexity of racial prejudice, discrimination, and segregation."88 Nevertheless, Professor Clark's work supported the broad inference that the plaintiffs were harmed as a result of racial prejudice, which was visibly manifested in school segregation.

Brown pioneered both the use of novel scientific evidence in federal civil rights litigation and exemplified the uncertainty surrounding the use of novel expert evidence. Novel scientific evidence often addresses issues at the frontiers of knowledge. These issues may pose difficulties even for the experts. The efforts of counsel and triers of fact to grapple with such issues are sometimes halting at best and incompetent at worst.89


Since the early part of this century, the federal courts have attempted to limit the uncertainty surrounding novel scientific evidence by establishing an evidentiary standard of reliability for scientific proof.90 Frye v. United States,91 decided in 1923, provided the standard that governed the introduction of expert evidence for more than half a century.92 The courts have also embraced procedures, including various forms of discovery, which provide the parties and the courts with greater opportunities to test the reliability of novel expert testimony.93 The standard of reliability for expert testimony and the applicable procedures in federal courts have, in recent years, undergone significant change.

A. Frye v. United States

As Judge Learned Hand observed at the beginning of this century, expert evidence must be reliable in order to have some "possible weight" on an issue and be admitted for consideration by a trier of fact.94 Absent reliability, the evidence would not be relevant to the inquiry.95 In Frye, the Court of Appeals for the District of Columbia considered an appeal from a trial court's refusal to admit the resultsof a test based on systolic blood pressure, offered to prove the truthfulness of a defendant in a murder prosecution.96 In an oft-quoted passage, the court crafted a standard to determine whether scientific evidence was sufficiently reliable to warrant consideration by a trier of fact:
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 forces 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 of 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.97

Frye contemplated two stages for acceptance of new science. First, the scientific community develops a theory and determines its reliability using scientific method.98 This stage required experimentation with the new science’s methodology and publication of the results for scrutiny and approval by the scientific community.99 Second, once the new science became "demonstrable," based on acceptance in the scientific community, the court could permit its use as evidence in the courtroom.100 Without explanation, the court of appeals chose "general acceptance" in the relevant scientific community as the standard for governing the admission of novel scientific evidence.101

Under Frye, the party proffering novel scientific evidence must show general acceptance by offering scientific publications, judicial decisions, evidence of practical use, or testimony by scientists on their peers' position regarding the evidence in question.102 Many courts, faced with determining the admissibility of a wide array of scientific evidence, favored the Frye standard.103 Often, new scientific evidence failed to survive this demanding standard. For example, McCormick on Evidence reports:
Polygraphy, graphology, hypnotic and drug induced testimony, voice stress analysis, voice spectrograms, ion microprobe mass spectroscopy, infrared sensing of aircraft, retesting of breath samples for alcohol content, psychological profiles of battered women, and child abusers, post traumatic stress disorder as indicating rape, astronomical calculations, and blood group typing, all have fallen prey to [Frye;s] influence.104

Many rationales have been offered to support the use of the Frye standard as a means of excluding evidence. The justifications included: that the standard guaranteed a minimum number of knowledgeable experts; that it promoted uniformity of decisions; that it eliminated the need for time consuming hearings on admissibility; and, most importantly, that it assured a method by which those best qualified to assess the validity of scientific evidence would effectively determine its admissibility.105

The general acceptance test of Frye became the "dominant standard for determining the admissibility of novel scientific evidence at trial."106 Indeed, Professor Clark's testimony in Briggs that the doll tests were "generally accepted as indications of the child's sensitivity to race as a problem" was calculated to satisfy Frye.107 Nonetheless, as Justice Blackmun noted in Daubert, the merits and application of Frye were extensively debated by commentators.108 Professor McCormick was one of the primary critics of Frye prior to the adoption of the Federal Rules of Evidence. In 1972, he wrote:
"General scientific acceptance" is a proper condition for taking judicial notice of scientific facts, but not a criterion for the admissibility of scientific evidence. Any relevant conclusions which are supported by a qualified expert witness should be received unless there are other reasons for exclusion. Particularly, probative value may be overborne by the familiar dangers of prejudicing or misleading the jury . . . . If the courts used this approach, instead of repeating a supposed requirement of "general acceptance" not elsewhere imposed, they would arrive at a practical way of utilizing the results of scientific advances.109

B. Federal Rule of Evidence 702

The Federal Rules of Evidence, effective July 1, 1975,110 provided the first modern and uniform set of evidence rules for the trial of civil and criminal cases in the federal courts.111 Rule 702, which governs the admission of expert testimony, does so in terms that do not expressly address reliability:
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.112

The Advisory Committee on Evidence, appointed by the Supreme Court, formulated the language which Congress adopted as Rule 702.113 Rule 702 and the accompanying Advisory Committee Note echo Professor McCormick's criticism of Frye. Reliability should depend on relevance rather than the general acceptance of scientific evidence.114 Rule 702 incorporates a relevancy requirement by permitting the introduction of scientific evidence which "will assist the trier of fact to understand the evidence or to determine a fact in issue."115 Surprisingly, the Advisory Committee Note made no mention of Frye.116 Instead, the Committee quoted Professor Mason Ladd:
There is no more certain test for determining when experts may be used than the common sense inquiry whether the untrained layman would be qualified to determine intelligently and to the best possible degree the particular issue without enlightenment fromthose having a specialized understanding of the subject involved in the dispute.117

Thus, Rule 702 contemplated the admission of expert testimony that was relevant in the sense that such testimony would facilitate an understanding of scientific, technical, or other specialized facts to determine an issue.118

Nonetheless, when called on to apply Rule 702, the majority of federal courts continued to utilize Frye. The courts were understandably reluctant to accept the sub silentio overruling of a precedent of Frye's stature, and often incorporated the general acceptance standard into the relevance determination under Rule 702.119

A number of courts have gradually begun to abandon the general acceptance standard.120 In 1975, the Fourth Circuit affirmed the admission of a voice spectrogram analysis of telephoned bomb threats.121 The court found Professor McCormick's critique of Frye persuasive:
Unless an exaggerated popular opinion of the accuracy of a particular technique makes its use prejudicial or likely to mislead the jury, it is better to admit relevant scientific evidence in the same manner as other expert testimony and allow its weight to be attacked by cross-examination and refutation.122

This decision required only that scientific evidence be supported by a "demonstrable, objective procedure" rather than general acceptance.123 Three years later, the Second Circuit approved the admission of similar evidence in a prosecution on narcotics charges.124 The considerations governing admissibility, the court wrote, were the "probativeness, materiality, and reliability of the evidence."125 In addition, the court of appeals directed the district court to consider whether the evidence had "any tendency to mislead, prejudice, or confuse the jury."126

In 1985, the Third Circuit decided United States v. Downing,127 the most significant precursor to Daubert. In Downing, the court considered the admissibility of expert testimony concerning the reliability of eyewitness identification.128 The court concluded that the language and spirit of the Federal Rules of Evidence, in addition to the experience of the courts in attempting to apply Frye, suggested that an approach more flexible than the general acceptance test for the admissibility of novel scientific evidence was appropriate.129 Downing instructed the district courts to undertake a preliminary inquiry as to the soundness of the theory or technique on which proffered scientific evidence was based.130 This inquiry was to include consideration of the risk that the jury would be overwhelmed, confused or misled and assessment of the materiality of the evidence to the issue in dispute.131

The Third Circuit envisioned a multi-factored analysis of the reliability of the evidence.132 The court permitted, but did not require, the identification of a relevant scientific community and a determination of the degree of acceptance within that community.133 In language reminiscent of Frye, the court suggested that in many cases, the general acceptance factor was likely to be decisive.134 Additional factors that district courts could consider included the novelty of the technique and its relationship to established modes of scientific analysis, the existence of specialized literature dealing with the technique, the likelihood that the scientific basis of the new technique has been exposed to critical scientific scrutiny, the qualifications and professional stature of the expert witness, and the potential and actual non-judicial uses of the scientific technique.135

According to Downing, district courts should also focus on the risk of error, both the frequency with which the method leads to erroneous results and the type of error generated by the technique.136 Finally, the district courts should consider whether the expert testimony had been offered in earlier cases to support or dispute the merits of a particular procedure. 137 The Downing opinion noted that "other factors could be added to the list."138 The Third Circuit's articulation of a clear alternative to Frye set the stage for the Supreme Court's resolution in Daubert of the conflict among the circuits over the appropriate standard of reliability for scientific evidence under Rule 702.

C. Assessment of Reliability of Scientific Evidence in Civil Rights Cases Decided Prior to Daubert

The civil rights cases decided after the adoption of Rule 702, but prior to Daubert, reflected the different approaches of the courts described in the preceding section. Occasionally, courts would restate and apply the Frye general acceptance test.139 Some courts adopted a hybrid approach that incorporated the general acceptance standard into the determination of relevance under Federal Rule of Evidence 702.140 Still other courts jettisoned Frye and attempted to assess for themselves the reliability of scientific evidence.141

Dang Vang v. Vang Xiong X. Toyed142 illustrates the first approach. Female Hmong refugees from Laos brought an action pursuant to 42 U.S.C. õ 1983143 against an employee of a Washington State Employment Security office who allegedly raped them when they contacted him about obtaining employment.144 The district court allowed extensive anthropological testimony, including a general explanation of Hmong culture, the longterm reliance of the Hmong on governmental agencies for support, and the role of women in that culture.145 The court found such testimony to be both relevant and necessary because it assisted the jury in understanding certain behavior of parties that might otherwise be confusing, such as the plaintiffs' continued contact with the defendant after a rape.146 The court excluded opinion testimony regarding the specifics of the case, such as whether there was a rape and why these particular plaintiffs did not report the rape.147 On appeal, the defendant maintained that all of the expert testimony should have been excluded because it failed to satisfy the requirements of Frye.148 The Ninth Circuit did not question appellant's citation to Frye. Instead, the court rejected the argument as inapposite because the testimony below derived from anthropological study of the Hmong, rather than a novel scientific theory, and therefore should not be scrutinized under Frye.149

United States v. Kozminski150 exemplifies the hybrid approach, where the court incorporates the Frye standard into the relevance determination under Rule 702.151 Kozminski was an appeal from a criminal conviction for violation of civil rights.152 Appellants, a dairy farmer and his wife, were convicted of willfully holding two retarded farm workers in involuntary servitude153 and of conspiring to deprive the workers of their constitutional right to be free from involuntary servitude154 as guaranteed by the Thirteenth Amendment.155 The couple's son was also convicted on the conspiracy charge.156 The Kozminskis argued on appeal that the district court erred in admitting expert psychological testimony to show that the two victims were detained against their will.157 A psychologist testified that the victims' limited mental ability, combined with the psychological pressures exerted on them by the conditions at the dairy farm, created an "involuntary conversion" to complete dependency.158 The Sixth Circuit, sitting en banc, held that the district court improperly admitted this evidence.159 The court explained:
For expert testimony to be admissible under Rule 702, a fourpart test must be met: (1) a qualified expert; (2) testifying on a proper subject; (3) in conformity to a generally accepted explanatory theory; (4) the probative value of which outweighs any prejudicial effect.160
According to the Sixth Circuit, the only arguably relevant theory shown to have general acceptance by the trial testimony was the "captivity syndrome" associated with the brainwashing of prisoners of war.161 The appellate court was not satisfied that any established theory existed to support a conclusion that the Kozminskis' actions resulted in complete dependency on the part of the victims: "As bad as conditions on the Kozminski's dairy farm are alleged to be, they fall short of those found in a Chinese prison camp. Accordingly, captivity syndrome is inapplicable as a matter of law given the facts of this case."162 Because Frye’s requirement of a generally accepted explanatory theory was not met, the court held the testimony inadmissible under Rule 702.163

Spencer v. General Electric Co.164 typifies the third approach mentioned above, where the court attempts its own assessment of the scientific reliability of proffered expert testimony.165 Spencer involved a Title VII sexual harassment claim and state tort claims against a former supervisor and employer brought by an employee claiming to be a victim of rape and other sexual misconduct.166 At trial, the plaintiff attempted to introduce the testimony of a forensic psychiatrist that plaintiff suffered from Post Traumatic Stress Disorder (PTSD) as proof that the rape actually occurred.167

Ultimately, the district court held the testimony inadmissible for this purpose.168 Noting that PTSD is a condition recognized in psychiatry as the emotional reaction to traumatic events, such as rape, the court cited the American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders for the proposition that PTSD may be caused by a variety of traumatic events outside the range of common experiences, such as military combat, bombing, torture, airplane crashes, or rape.169 In the case of rape, the condition is sometimes labeled Rape Trauma Syndrome (RTS).170 The court concluded, however, that evidence of PTSD or RTS was not a scientifically reliable means of proving that a rape occurred:
Evidence of PTSD occasioned by rape . . . is not a scientifically reliable means of proving that a rape occurred. PTSD is simply a diagnostic category created by psychiatrists; it is a human construct, an artificial classification of certain behavioral patterns. RTS was developed by rape counselors as a therapeutic tool to help identify, predict, and treat emotional problems experienced by the counselor’s clients or patients. It was not developed or devised as a tool for ferreting out the truth in cases where it is hotly disputed whether the rape occurred. "Unlike fingerprints, blood tests, and lie detector tests, RTS was not devised to determine the 'truth' or accuracy of a particular past event--i.e., whether, in fact, a rape in the legal sense occurred." . . . "The scientific evaluation of rape trauma syndrome has not reached a level of reliability that surpasses the quality of common sense evaluation present in jury deliberations."171
While the district court made its own determination of the reliability of the proffered evidence, its opinion did not completely ignore Frye. The court questioned several authorities which had admitted PTSD or RTS evidence under the Frye test based on findings that the disorders were "generally accepted to be a common reaction to sexual assault."172 The court opined that the relevant issue was not whether rape victims may display certain symptoms, but whether diagnosis of PTSD or RTS provided scientifically reliable proof that an alleged victim was raped.173 Thus, the court believed that, under Frye, the evidence should not be admitted for this purpose.174 After trial, the district court held that the employee failed to prove by a preponderance of evidence that the alleged sexual assaults and rape took place.175 The evidence issue was not raised on appeal, and the Fourth Circuit affirmed.176

The court's exclusion of the psychiatric evidence of PTSD to corroborate the plaintiff's testimony that she was raped, on grounds that such evidence was irrelevant, seems questionable. The diagnosis of the plaintiff with a disorder that experts recognize as affecting persons who have suffered significant trauma subsequent to the date of the alleged incident was relevant because it tended to support her testimony that she had indeed been raped. Such evidence is relevant even if the diagnosis standing alone did not show the cause of the condition.177 The court's evidentiary ruling in Spencer has not been cited by any other federal court. Nonetheless, the decision illustrates the types of issues which a court following the third line of authority must address in an effort to determine for itself the reliability of scientific proof in a civil rights action.


The conflicting lines of authority, whether to use Frye, Federal Rule of Evidence 702, or a hybrid of the two, remained unreconciled until the Supreme Court granted review in Daubert v. Merrell Dow Pharmaceuticals, Inc.178 Interestingly, significant impetus for review of the case may have come from within the judicial rulemaking process. In June 1991, the Advisory Committee on Civil Rules of the Judicial Conference of the United States proposed amendments to both the Federal Rules of Civil Procedure and the Federal Rules of Evidence.179 The amendments included a revised Rule 702, which would have allowed the admission of expert testimony only if it was "reasonably reliable" and would "substantially assist the trier of fact to understand the evidence or to determine a fact in issue."180 TheCommittee Notes suggested that this revision was intended to limit the use, while increasing the utility and reliability, of expert testimony.181 The proposal contemplated that the courts should "reject testimony that is based upon premises lacking any significant support and acceptance within the scientific community."182 The Committee summary further indicated an intent to address unwarranted increases in litigation costs resulting from the use of unreliable expert testimony.183

The Supreme Court's Order of April 22, 1993, adopted many of the civil rule amendments proposed by the Committee.184 These amendments were part of the comprehensive changes which became effective December 1, 1993.185 The Court, however, granted certiorari in Daubert on October 13, 1992,186 and the proposed modification of Rule 702 did not emerge from the rulemaking process. Instead, the Supreme Court addressed the Advisory Committee's concerns in Daubert.187

Daubert is now the best known of the many products liability cases involving the anti-nausea drug Bendectin.188 During the 1980s, approximately 1700 actions were brought alleging that the drug caused birth defects.189 Plaintiffs Jason Daubert and Eric Schuller were minor children born with serious birth defects.190 They sued Merrell Dow alleging that Bendectin caused their injuries.191

Merrell Dow moved for summary judgment in the district court, arguing that Bendectin did not cause birth defects in humans and that petitioners could offer no admissible evidence to support theirclaim.192 Merrell Dow supported its motion with an affidavit of a physician whom Justice Blackmun, writing for the Court, described as a "well-credentialed expert on the risks of exposure to various chemical substances."193 The affidavit stated that none of the more than thirty published epidemiological studies involving over 130,000 patients had found Bendectin to be capable of causing malformations in fetuses and concluded that Bendectin was not a risk factor.194

The plaintiffs did not dispute the description of the published research, but rather presented the testimony of eight experts whose credentials the court noted were also "impressive."195 The experts, testifying that Bendectin could cause birth defects, based their testimony on test tube and live animal studies suggesting causation, analyses of pharmacological similarities between Bendectin and other substances known to cause birth defects, and reanalyses of the published studies on Bendectin.196

The district court examined plaintiffs' evidence under the Frye standard,197 which the Ninth Circuit had reaffirmed in United States v. Kilgus.198 The district court recognized the extensive body of generally accepted epidemiological data available on Bendectin.199 Consequently, it held that plaintiffs' test tube, live animal, and pharmacological studies, which were not based on epidemiological data, could not be admitted to prove causation.200 The district court further held that plaintiffs' reanalyses of the published epidemiological studies were inadmissible because plaintiffs' experts had not published these studies and their peers had not reviewed them.201 Under the district court's analysis of the evidence, the plaintiffs offered no proof that Bendectin caused their birth defectsand therefore the district court granted Merrell Dow's motion for summary judgment.202

The Court of Appeals for the Ninth Circuit affirmed.203 The court discussed the Frye rule, that expert opinion based on a scientific technique is inadmissible unless the technique is generally accepted as reliable by the relevant scientific community.204 Evidence based on techniques that diverged significantly from techniques accepted by recognized authorities in the field, the court reasoned, could not meet the standard of general acceptance.205 The medical field generally accepted epidemiological studies to show causation of birth defects, and therefore the court did not permit other evidence of causation to be admitted.206 Thus, the Ninth Circuit concluded that the district court properly excluded plaintiffs' test tube, live animal, and pharmacological studies.207 In addition, the district court correctly excluded plaintiffs' evidence based on reanalyses of epidemiological data.208 While the medical community utilized reanalyses, such studies were generally accepted only after they were subjected to review by others in the field.209 The reanalyses in question had been prepared for the Daubert litigation and had not been reviewed by the scientific community.210 According to the Ninth Circuit, it did not suffice that scientific proof met some of the requirements of the scientific community; the evidence had to meet all of the essential requirements.211 Accordingly, the court of appeals upheld the exclusion of the reanalyses.212

The Supreme Court granted review in Daubert to resolve the "sharp divisions regarding the proper standard for admission of expert testimony."213 The primary issue presented was whether the adoption of Federal Rule of Evidence 702 eliminated the general acceptance test of Frye for the admission of scientific evidence.214 Secondarily, the Court was asked to consider whether, if Frye remained valid,Rule 702 required that expert scientific testimony undergo peer review to be admissible in evidence.215

The Justices unanimously held that the adoption of the Federal Rules of Evidence superseded Frye.216 Interpreting the legislatively-approved rules as it would any statute,217 the Court found that nothing in the text of Rule 702 required general acceptance as a foundation for the admission of scientific evidence, and there was no clear indication that the drafters intended the new rules to incorporate this standard.218 The Court construed the drafters' omission of any reference to the Frye test in either the text or the Advisory Committee Note as indicating that Frye was no longer good law.219 Moreover, in the Court's view, this rigid test was incompatible with the "liberal thrust" of the Federal Rules of Evidence and henceforth should no longer be applied in federal trials.220

In place of Frye, the majority articulated a two-part test, directing that "the trial judge must ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable."221 According to the Court, the primary source of this duty is the language of Rule 702, which first requires that the expert testimony convey "scientific knowledge."222 This characterization indicates that purported scientific testimony must be based on "scientific method or procedure" and comprise more than "subjective belief or unsupported speculation."223 Scientific testimony need not be certain, but must meet a standard of evidentiary reliability or trustworthiness.224 Rule702's use of the term "knowledge" required that the testimony be supported by appropriate validation consisting of "good grounds based on what is known."225 In addition, the majority explained, Rule 702 requires that there be a sufficient "fit" between the scientific testimony and the facts of the case so that the testimony will assist the trier in finding the facts.226 Displaying uncharacteristic whimsy, Justice Blackmun explained that absent an acceptable showing of such a nexus, evidence on the phases of the moon indicating that it was full on a certain night could not be received to show that a particular individual was behaving irrationally on that evening.227 He cautioned, however, that this relevance determination will not always present an obvious question, as the validity of scientific evidence can vary depending on the purpose for which it is used.228

A court exercising its gatekeeping function regarding a proffer of expert scientific evidence229 must find that the proponent has established, by a preponderance of the evidence, the foundation facts.230 In making this preliminary determination, however, the court is not bound by the evidentiary rules.231 The Court identified some of the factors which bear on the determination as to whether the evidence is scientific, but did not attempt to provide a definitive checklist.232

Ordinarily, a key question is whether the proffered theory or technique can be and has been tested.233 As the Court noted, "'scientific methodology today is based on generating hypotheses and testing them to see if they can be falsified.'"234 A second consideration is whether the theory or technique has been subjected to peer review and publication.235 Although publication is not necessary for admissibility, and in some instances may not ensure reliability, exposure to the review process supports admission because it increases the likelihood that the scientific community will detect any error that exists.236 For particular techniques, the district court should consider the known or potential rate of error and any professional standards that may be applicable.237 Lastly, the court may still consider the general acceptance of a technique by explicitly identifying a relevant scientific community and expressly determining the degree of acceptance in that community.238 "Widespread acceptance can be an important factor" in admitting evidence, and the district court may be properly skeptical of a known technique that has garnered only minimal support within the community.239

The Daubert opinion emphasized that the district court should be flexible in conducting its inquiry and should focus on the principles and methodology that underlie the evidence, not on the conclusions they generate.240 The Court acknowledged its reliance on Downing and, in an obvious invitation to the lower courts to expand on the factors enumerated in the majority opinion, suggested that the approaches offered by the Third Circuit and a number of other sources on the reliability determination "may well have merit."241 The sources cited included a standard treatise242 and contributions by Professors Mark McCormick243 and Margaret Berger.244

The majority cautioned that a district court considering a proffer must be mindful of other rules of evidence.245 Expert evidence based on otherwise inadmissible hearsay may be admitted pursuant to Rule 703 only if the underlying facts or data are of a type "reasonably relied upon by experts in the field in generating inferences or opinions upon the subject."246 Rule 706 authorizes the court to appoint an expert to assist with the case.247 In addition, the court may exclude evidence under Rule 403 "if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury."248 The majority noted that this provision allows judges greater control over experts than other witnesses, as "'expert evidence can be both powerful and quite misleading because of the difficulty in evaluating it.'"249

Daubert concluded by responding to some of the policy concerns expressed by the opposing parties and numerous amici in the case.250 The Court stated that it did not expect that the abandonment of Frye would result in a free-for-all in which juries would beconfounded by "pseudoscientific" offerings.251 Merrell Dow was "overly pessimistic" about the ability of the jury to address scientific evidence, and the efficacy of the adversary system.252 At trial, vigorous cross-examination, introduction of opposing evidence, and careful jury instructions as to the burden of proof adequately address the potential problems presented by "shaky but admissible evidence."253 Moreover, if a court believes that the evidence is insufficient to support a favorable finding by a reasonable juror, the court may either direct a judgment at trial or grant summary judgment.254

The Daubert majority was satisfied that these devices adequately insure the integrity of the truth-seeking process where scientific evidence is admitted in a case. Unlike scientific inquiry, legal fact finding is generally not subject to revision as additional data becomes available, but rather must settle issues within the constraints of a dispute resolution procedure.255 While the gatekeeping role played by a judge may occasionally result in the exclusion of valuable insights, the rules of evidence sanction this balance in order to resolve issues in the context of the legal process.256

Justice Stevens joined Chief Justice Rehnquist in partial dissent.257 While agreeing that Frye did not survive the enactment of the Federal Rules of Evidence,258 these Justices disassociated themselves from the Court's effort to sketch the contours of the new test, calling the Court's observations "not only general, but vague and abstract."259 They expressed concern that the scientific subject matter of the briefs was outside the expertise of the judiciary.260 In particular, they questioned the competence of federal judges to decide in the first instance whether a scientific theory can be and has been tested.261 While not disputing the appropriateness of a gatekeeping function, they cautioned that amateur science was not within the jurisdiction of the courts.262

While courts and commentators have debated at some length whether Daubert will affect the admissibility of various types ofscientific evidence,263 Daubert did not contemplate a revolutionary change in the practice of the federal courts. In particular, the Court retained Frye's general acceptance standard as an "important factor" bearing on admissibility.264 Under the Court's formulation of the standard for Rule 702, district courts are free to retain all prior jurisprudence on the reliability of various scientific methods.265 At the same time, Daubert's emphasis that the inquiry it envisioned was to be "a flexible one"266 is calculated to allow the trial court to scrutinize the reliability of techniques that it views with skepticism, even when proponents have shown general acceptance. Daubert, however, also affords the district court the freedom to consider new methods of proof for which no such claim of acceptance can yet be made.


In the civil rights context, the most significant aspect of the Daubert decision is the Supreme Court's directive that district court judges play an activist role as gatekeepers when a party offers expert evidence.267 The Supreme Court's reading of the Federal Rules of Evidence, especially Rule 702, as imposing on a trial judge a duty to "ensure" that expert testimony is scientifically reliable, will substantially affect civil rights litigation.268 The remainder of this Article will address the post-Daubert development of evidentiary standards and practice with respect to novel expert evidence in federal civil rights cases.

A number of factors will impact a court's role as gatekeeper under Daubert. These factors include the scope of the court's discretion withrespect to the admission of expert evidence,269 the court's philosophy with respect to this evidence,270 and the duty of the court to exercise its discretion.271 Moreover, the procedural context and type of expert evidence should play a significant role in the court's exercise of its discretion. In civil rights actions, the courts should favor the admission of novel expert evidence to facilitate the resolution on the merits of issues involving basic personal rights and social justice.272

A. The Scope of Discretion

A district court has wide discretion in determining whether to admit or exclude evidence, particularly expert testimony.273 An appellate court will generally accord the district court wide latitude in the proper exercise of discretion274 under Daubert and will reverse its findings only if they are manifestly erroneous or an abuse of discretion.275 For example, in a police misconduct case, the Seventh Circuit affirmed the exclusion of a pathologist's testimony regarding the effects of electroshockbecause the reliability of his proffered testimony was doubtful and the panel did not think the district judge had abused his discretion.276 Likewise, in another police misconduct case, the Eighth Circuit affirmed a district court's refusal to admit the testimony of a neurologist because the plaintiff was unable to explain how the expert's discipline could shed light on the causation of his injury.277 The court of appeals stated that it would reverse the ruling excluding expert testimony "only for an abuse of discretion."278

B. Gatekeeping in Every Case?

Daubert may require that the district court exercise its discretion in every case. Daubert states that "under the rules, the trial judge must ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable."279 Read literally, this directive appears to require a determination by the court as to all such evidence, even absent an objection.280 The preface "under the rules" does not clearly indicate otherwise. As the Court goes on to explain in the next paragraph, "[T]he primary locus of this obligation is Rule 702, which clearly contemplates some degree of regulation of the subjects and theories about which an expert may testify."281 In addition, the Court's later restatement of this duty indicates that the district court judge is to apply the test when "[f]aced with a proffer of expert testimony."282 While the practice in some jurisdictions has been to proffer the qualification of an expert for court approval before examination of the substance of the testimony begins,283 this practice is not required by the rules and has repeatedly met with disapproval from at least one circuit court.284 Thus, Daubert may find in Rule 702 a court duty to scrutinize the relevance and reliability of all expert evidence even if the party against whom such evidence is offered makes no objection.285 In effect, under Daubert, the erroneous admission of expert evidence by the district court would be plain error.286287 Given this potential for prejudice, reviewing courts might invoke the plain error rule to address the admission of irrelevant or unreliable expert evidence. Therefore, Daubert may require trial courts to perform their gatekeeping duty whenever scientific evidence is admitted.

One district court has taken this position in an action brought by death row inmates at California's San Quentin State Prison to challenge execution by lethal gas as violating the Eighth Amendment.288 Noting that neither party had challenged the admissibility of scientific evidence regarding the pain caused by lethal injection, the district court nonetheless considered itself bound to scrutinize this proof under Daubert.289 Accordingly, the court analyzed the evidence and ruled sua sponte that the expert evidence was admissible.290 Whether the courts will consistently adopt this reading of Daubert remains to be seen.291 If they do, they will have an opportunity to inject their philosophy with respect to the nature and purpose of gatekeeping into every case.

C. Philosophy of the Court

The gatekeeping duty articulated in Daubert plays a central role in subsequent civil rights cases. Interestingly, the courts have described the duty in substantially different ways.292 Many courts simply quote the Daubert directive that courts must ensure expert evidence is "not only relevant, but reliable."293 Some courts characterize their duty in relatively neutral terms. For example, in a civil rights action brought by the representative of the estate of a motorcyclist who police killed during a high-speed chase, the Fifth Circuit, when excluding the testimony of an inadequately qualified accident reconstructionist, simply cited Daubert for the proposition that "Rule 702 . . . clearly contemplates some degree of regulation of the subjects and theories about which an expert may testify."294 A district court issuing a protective order against psychological testing in an employment discrimination action observed that Daubert has "injected the trial judge into the expert testimony area in a more active sense than before by requiring . . . inquiry into a number of factors bearing on reliability."295

By contrast, the Seventh Circuit, in a civil rights action brought by the convicted murderer of two police officers who claimed that the police obtained his confession by torture, commented on Daubert in a way that suggests gatekeeping involves maintaining a barrier rather than an entrance:
The elimination of formal barriers to expert testimony has merely shifted to the trial judge the responsibility for keeping "junk science" out of the courtroom. It is a responsibility to be taken seriously. If the judge is not persuaded that a socalled expert has genuine knowledge that can be genuinely helpful to the jury, he should not let him testify.296

In civil rights actions, the better view is that the district court should incline toward admitting novel expert evidence. These cases assert basic personal rights and often raise broad social justice issues. Many of these cases implicate expressive and associational rights at the core of the First Amendment.297 In this context, proffered expert evidence takes on an aspect of political speech.298 Public interest in having a jury or judge resolve civil rights cases on the merits is strong,299 and, accordingly, the court should exclude expert evidence only if such evidence is clearly inadmissible.

D. Procedural Context and the Court's Discretion

Another factor which should significantly affect the district court's discretion in gatekeeping is the procedural context.300 Both the parties and the courtcan potentially raise gatekeeping issues in a wide variety of contexts, including pretrial and case management conferences, discovery, summary judgment, trial, and post-trial proceedings.301 A hypothetical federal suit to enjoin a city from requiring that a fire fighter submit to HIV testing illustrates this point. Plaintiff's claim is based on the Fourth and Fourteenth Amendments302 which, under the relaxed standard applicable to government searches of its employees for management purposes, require only that the test be reasonable under all the circumstances.303 In the hypothetical, plaintiff's counsel learns that the city has consulted with a physician who advised them that other means of transmitting HIV, in addition to those currently recognized in the medical literature, exist. Plaintiff's counsel plans to argue that a fire fighter's risk of contracting or transmitting HIV on the job is infinitely small, but is concerned about the potential effect of this physician's testimony on the outcome of the case.

1.Pretrial discovery, scheduling, and reports

The Federal Rules of Civil Procedure, particularly amendments effective December 1, 1993,304 afford counsel and the court early opportunities to raise issues relating to possible expert testimony by the physician. Except in categories of cases exempted by local rules,305 the Rules of Civil Procedure now require the prompt issuance of a scheduling order to govern the conduct of the litigation.306 Prior to the issuance of the order, the parties must meet to discuss their claims and possible settlement of the case.307 The parties must also discuss both the conduct of discovery and the mandatory disclosure of information without discovery requests, including disclosure of expert testimony.308 After meeting, the parties must submit a written report to the court for its consideration in issuing the scheduling order.309 The court may also hold a scheduling conference to discuss the report prior to issuing the order.310 All of these events present opportunities to consider expert testimony issues.

In most cases these discussions will focus on questions of scheduling, as neither the parties nor the court are likely to have sufficient familiarity with issues of expert proof to be able to explore them in great detail this early in the litigation. Nevertheless, if well prepared, counsel in the hypothetical civil rights case will find that these procedures afford numerous opportunities to develop issues under Daubert. For example, while discussing the bases of their claims and defenses at a meeting of the parties,311 counsel may question the city's attorney regarding the physician's theory and the relevance and reliability of any supporting scientific proof. Such discussion might provide plaintiff's counsel with informal discovery as to the preparedness of opposing party to offer this evidence. This information may offer insight regarding the level of opposing counsel's sophistication with respect to scientific evidence and tactical guidance as counsel plans discovery.

The report drafted by the parties may address a variety of subjects related to expert testimony. The 1993 amendments to the FederalRules of Civil Procedure, except as otherwise provided by local rule312 or court order, obligate the parties to disclose the identity of any person who may present expert evidence at trial,313 and, with respect to each witness who is "retained or specially employed to provide expert testimony in the case or whose duties as an employee of the party regularly involve giving expert testimony," to provide a written report containing "a complete statement of all opinions to be expressed and the basis and reasons therefor."314 Unless the court orders otherwise, these disclosures must occur at least ninety days prior to trial.315 The parties may propose to the court changes in the "timing, form, or requirement" for these disclosures.316 In the hypothetical, plaintiff's counsel may want to propose that the court set an earlier time for the disclosure of expert testimony and require that it include facts supporting the admissibility of the physician's evidence.317

The report must contain the parties' views regarding the subjects and timing of discovery, including "whether discovery should be conducted in phases or be limited to or focused upon particular issues"318 and "what changes should be made on the limitations on discovery under these rules."319 Plaintiff's counsel may request early discovery on gatekeeping issues. The parties also may propose modifications to the significant limitations on expert discovery imposed by the 1993 amendments.320 While the new rules provide for depositions of testifying experts321 and require supplementation of both the expert's deposition testimony and report,322 they also limit interrogatories to twenty-five per party.323 Thus, a favored low-cost discovery tool for plaintiffs in civil rights cases may be substantially unavailable unless plaintiff convinces the court, prior to the issuance of the initial scheduling order, of the need for additional interrogatories. The rules also restrict depositions, which comprise the most effective discovery technique, to only ten per side.324 The rules' prohibition on depositions of experts who must provide reports until after the report has been provided325 is also troublesome for parties concerned with gatekeeping issues. Left unmodified, these provisions may narrowly constrain expert discovery. In the hypothetical civil rights case, plaintiff's counsel may not require additional depositions, but might seek earlier disclosure of the physician's testimony and leave to serve additional interrogatories to prepare to depose the physician and, ultimately, dispose of his testimony by pretrial motion.326 Finally, the parties' report may propose orders on any subject that a court is authorized to consider at a scheduling or pretrial conference.327 The court hearing the hypothetical case may be receptive to suggestions for orders that schedule mandatory disclosures, discovery, conference dates, and motion deadlines to allow an early disposition of gatekeeping issues with respect to the physician's testimony.328 2.Pretrial conferences

The pretrial conference presents additional opportunities to discuss issues under Daubert. The 1993 amendments to the Federal Rules of Civil Procedure now provide that the court may consider and enter appropriate orders with respect to "limitations or restrictions on the use of testimony under Rule 702 of the Federal Rules of Evidence" ata pretrial conference.329 The Advisory Committee Notes indicate that the revision was intended
to clarify that in advance of trial the court may address the need for, and possible limitations on, the use of expert testimony under Rule 702 of the Federal Rules of Evidence. Even when proposed expert testimony might be admissible under the standards of Rules 403 and 702 of the evidence rules, the court may preclude or limit such testimony if the cost to the litigants--which may include the cost to adversaries of securing testimony on the same subjects by other experts--would be unduly expensive given the needs of the case and the other evidence available at trial.330

Such issues may, of course, arise at a pretrial conference in the context of a discovery dispute.331

The court should exercise restraint in addressing these issues at a pretrial conference. While a conference may occasionally be an appropriate setting to discuss limiting expert testimony based on cost, the conference itself is not an appropriate forum to determine the admissibility of expert testimony under Daubert. The admissibility of expert testimony is a preliminary question for determination by the court under Federal Rule of Evidence 104(a).332 Daubert requires that the proponent of the evidence demonstrate to the court by a preponderance of proof that the expert will testify with scientific knowledge to assist the trier of fact in understanding or determining a fact in issue.333 The trial court must make findings with respect to these issues.334 Obviously, an adversary procedure, such as a hearing on a motion rather than a conference, is required.335 Thus, in the hypothetical civil rights case, the conference would afford plaintiff's counsel an opportunity to discuss gatekeeping issuesregarding the physician's testimony with the court and establish further procedures to resolve them.336

The procedure most likely to be used for this purpose is a motion in limine. A motion in limine is a request filed by the opposing party for a pretrial ruling on the admissibility of evidence.337 District courts now routinely hear this type of motion to decide gatekeeping issues in civil rights cases.338 Assuming discovery casts suspicion on physician's theory that there are other means to transmit HIV is unreliable, plaintiff's counsel is likely to file a motion in limine to request an order prohibiting testimony as to the theory at trial.

3. Summary judgment and judgment as a matter of law

Occasionally, courts utilize summary judgment to address gatekeeping issues prior to trial. 339Typically, the courts determine whether challenged evidence is admissible in assessing whether there is a "genuine issue as to any material fact"340 that would require a trial.341 In the hypothetical case, this motion might result in a determination that the physician's theory is inadmissible, but it is unlikely to yield a summary judgment for the plaintiff unless the city has no other evidence on the reasonableness of the HIV tests. The district court may, of course, decide these issues during trial,342 and in the hypothetical case would likely do so if plaintiff's counsel did not file a pretrial motion. Disposition of gatekeeping issues at trial is appropriate where the development of an adequate record requires the factual background of trial evidence.343 In particular, a court may defer ruling on the relevance of expert proof until a more complete record is developed at trial.344 If potentially inadmissible expert proof is essential to a party's case, the court, in either a jury or bench trial, may direct the parties to present evidence with respect to the issue early in the trial. The court can then assess the admissibility of the expert evidence and decide at that point whether it should enter judgment as a matter of law.345 In a jurytrial, the court may also defer a gatekeeping determination until a party makes a motion for judgment as a matter of law at the conclusion of plaintiff's case.346 In a bench trial, the court may make a gatekeeping decision upon a motion for judgment347 or after the submission of all evidence.348

4.Post-trial motions

Post-trial motions in civil rights cases also may raise gatekeeping issues. In a motion for new trial, a party may argue that the district court erred in its ruling to admit or exclude evidence.349 Parties may combine the motion for new trial with a motion for judgment after trial in a jury case350 or a motion to amend the judgment in a case tried to the court.351 Other motions, which do not challenge the judgment, such as a request for an award of attorneys' fees, may also present gatekeeping issues.352

5. Gatekeeping, fairness, and finality

The procedural stage at which a gatekeeping issue arises should significantly impact the court's exercise of its discretion. As a general rule, the court should exercise considerable restraint early in a case. As the history of Dr. Clark's testimony in Brown indicates, the parties may themselves develop significant scientific evidence during the course of the proceedings.353 Unless there are substantial countervailing factors, such as a pending dismissal of the case354 or undue cost,355 fairness to the parties will usually require that courts allow the parties a reasonable opportunity to develop novel expert evidence and opposition to such evidence at the pretrial stage of a case.356 In addition, as Brown illustrates, the uncertainties accompanying the use of this type of evidence warrant caution. The court must acquire a working knowledge of the evidence to properly determine its relevance, reliability, and, ultimately, if the evidence is admitted, its persuasive value. Thus, a court should generally afford the parties a great deal of latitude when gatekeeping issues arise in conferences and discovery disputes.

As the court considers the merits of the case, the court necessarily engages in much closer analysis because the policy of a "speedy and inexpensive determination of every action"358 takes on increased significance when a judgment or post-judgment ruling may appropriately be rendered. The court may then require that a party, unable to make the threshold showing of the relevance and reliability of its evidence, rest on its remaining evidence. Of course, where the threshold showing is marginal, the court may admit the evidence and expose it to the rigors of the adversary process.359

E. Tailoring Gatekeeping for Scientific, Technical, and Other Specialized Evidence

A district court should also tailor its gatekeeping to the category of evidence proffered. Rule 702 contemplates the admission of "scientific, technical, or other specialized knowledge."360 The drafters intended that this provision be given a liberal reading:
The rule is broadly phrased. The fields of knowledge which may be drawn upon are not limited merely to the "scientific" and "technical" but extend to all "specialized" knowledge. Similarly, the expert is viewed, not in a narrow sense, but as a person qualified by "knowledge, skill, experience, training or education." Thus within the scope of the rule are not only experts in the strictest sense of the word, e.g. physicians, physicists, and architects, but also the large group sometimes called "skilled" witnesses, such as bankers or landowners testifying to land values.361

Scientific, technical and other types of specialized knowledge are distinct types of evidence requiring different types of expertise.362 Daubert explicated the nature of these types of scientific evidence at some length.363 Technical evidence generally deals with the practical, mechanical, and industrial arts or the applied sciences and is derived by settled principles from the sciences.364 For example, architecture is based ultimately on the principles of mathematics, physics, and chemistry, but the practice of architecture is certainly not considered to be a matter of experimental science. The specialized knowledge category serves as a catch-all for other evidence, including skills, which are more subjective in nature. The proof of reliability for these categories of evidence should likewise differ. The Daubert factors are calculated to address reliability problems associated with scientific evidence alone, not with technical or other specialized evidence.365 Even with respect to scientific evidence, the Court encouraged district courts to explore various approaches.366 A requirement of proof based on scientific method is unnecessary to demonstrate the reliability of technical evidence which is based on settled principles.367 Such a requirement is also inappropriate for other specialized evidence that is by definition subjective in nature. The lower courts should, therefore, adopt a flexible approach to assessing the reliability of technical and other specialized evidence.368 Faced with a proffer of expert evidence, a court should, as a threshold matter, determine whether the evidence consists of scientific, technical, or other specialized knowledge. The court should then devise an appropriate test of reliability. If the evidence is scientific in nature, the court should follow Daubert. For technical evidence, the court should determine if it is drawn from a recognized field of knowledge.369 For other specialized evidence, the court should assess whether it is reasonably relied on to determine important matters in its field of application.370

The only civil rights case considering this issue to date correctly noted that "the distinction between scientific and nonscientific expert testimony is a critical one," and stated that Daubert was "of limited help" in assessing the reliability of a former sheriff's testimony regarding the effect of failure to discipline police on their use of deadly force.371 Nevertheless, the court did not attempt to fashion an appropriate standard to test the witness' necessarily subjective testimony regarding management principles. Instead, the court consulted the Daubert decision for "guidance as to how a court should carry out its gatekeeping function," and, applying all four of the Daubert reliability factors, held that the district court erred in failingto exclude the evidence.372 Hopefully, future decisions in the civil rights field will demonstrate greater creativity in assessing the reliability of technical and other specialized evidence.

V. Elements of Gatekeeping in Federal Civil Rights Cases

After determining the category of evidence—scientific, technical, or specialized--the court must next assess the relevance and reliability of the evidence under Federal Rule of Evidence 702.373 If the evidence satisfies these standards, but is based on otherwise inadmissible hearsay, under Federal Rule of Evidence 703, the court may also need to determine whether the underlying facts or data are "reasonably relied upon by experts in the particular field in forming opinions or inferences on the subject."374 In addition, the court may have to weigh the probative value of the evidence against its possible prejudice under Federal Rule of Evidence 403.375 Finally, in making all of these determinations, the court may also have to consider whether any additional procedures, such as the appointment of an expert under Federal Rule of Evidence 706376 or a special master under Federal Rule of Civil Procedure 53377 are warranted. Because civil rights cases define basic personal rights, the court should consider both traditional and non-traditional means to allow the presentation of novel expert proof.

A. Determining Relevance

Under Rule 702, the court assesses whether evidence will assist the trier of fact.378 Daubert cautions that this determination is not always obvious.379 Scientific evidence may be validly used for certain purposes, but not for others.380 District courts must identify specific issues whose resolution will be informed by the evidence. The relevance determination, however, is a familiar type of assessment and has not occasioned significant difficulty in civil rights cases reported since the Daubert decision. For example, in an appeal of a criminal conviction for holding a Sri Lankan household employee in involuntary servitude, the First Circuit held that the district court properly admitted the testimony of a victimologist on the issue of coercion.381 The appellate court stated that although "the generalized nature of the proffered testimony regarding reactions to abuse may temper its probative value to the factfinder, we do not think that it can be said that its relevance is negated entirely."382 Similarly, a district court considering the challenge to execution by lethal gas admitted testimony from specialists in diverse fields such as neurology, toxicology, anesthesiology, pathology, and pharmacology because the inquiry into consciousness and pain "required that the court hear testimony of qualified experts and weigh the strength of the examination and crossexamination in order to reach a determination."383 Another district court hearing a handicap discrimination case admitted the testimony of an ophthalmologist regarding the relationship between stress and high intraocular pressure as relevant to the issue of damages.384 Likewise, in an age discrimination case, the court allowed the testimony of a social psychologist on stereotypes in company documents because such testimony would help make the jury aware that bias may arise from unconscious motives.385 By contrast, in an action claiming children in a foster home suffered abuse, a court held inadmissible the testimony of an economist concerning future loss of enjoyment of life.386 Because the testimony was based on survey data, the court reasoned that the evidence comprised the consensus of persons no more expert than the jurorsand therefore would not assist the jury in reaching a decision.387 Similarly, in a wrongful death case arising out of a fatal shooting by police, the court, while expressing considerable skepticism regarding the theory of hedonic damages, excluded the testimony of an expert in part because his calculations were based on "the value of a statistical life--a nameless, faceless member of society."388 In the court's view, the expert failed to tailor his calculations to fit the case at hand and his testimony could therefore not assist the jury in awarding damages.389

B. Determining Reliability

Daubert noted several factors that a district court should consider to ensure that scientific evidence is reliable: (1) testing, (2) peer review and publication, (3) error rate and professional standards, and (4) general acceptance.390

1. Testing

Daubert indicated that a key factor in evaluating the reliability of a scientific theory or technique was "whether it can be (and has been) tested."391 The Court's language suggests issues with respect to the assessment of science based on observation of nature rather than experiment392 and the propriety of testing within the context of the litigation itself.393 These latter issues have only been addressed peripherally in civil rights cases subsequent to Daubert.394

These issues are, however, exemplified in a case claiming abuse of students in a residential facility for mentally retarded children.395 The magistrate judge396 considered a motion in limine to exclude testimony of a psychiatrist and two psychologists who examined the seven plaintiffs.397 As a result of the examinations, which consisted of a history, a psychological evaluation utilizing standardized tests, and a clinical interview, the witnesses determined that the plaintiffs had been sexually, physically, and emotionally abused.398 The focus of the expert evaluation was "to compare the behavior or 'symptoms' of the child to that of victims of child abuse."399

The court, citing Daubert, inquired whether the methodology used was "capable of being falsified, that is, whether it actually employed the 'scientific method.'"400 Answering in the negative, the magistrate found that this type of psychological evidence was both controversial and, for the most part, "irrefutable," inasmuch as it could only be tested by research on patients.401 As a result, the expert conclusions were not subject to the type of proof available in the physical sciences.402 In the absence of objective research to test the expert theories or assess their conclusions, the court found that the expert techniques did not satisfy the Daubert standard.403 Both the merits of this decision and its implications will no doubt be vigorously debated,404 but the court's approach is instructive for its effort to address the scientific problems of testing the expert testimony.

2.Peer review and publication

Under Daubert, peer review and publication are "pertinent considerations" for determining the reliability of scientific evidence.405 Where the evidence comes from the mainstream of its respective field, this consideration will weigh heavily in favor of admission.406 For example, the expert testimony in the execution by lethal gas case was primarily based on principles which commonly appeared in authoritative medical treatises.407 Accordingly, the court could presume it had been subjected to peer review and publication and accepted by the scientific community as having significant probative value.408 Where experts present new or marginal theories, this factor should not lend significant support to the admission of evidence. Thus, the magistrate hearing the mentally retarded children's abuse case gave little weight to controversial literature on the symptomatology of abuse.409 If the circumstances are such that viable theories are likelyto be published and subject to peer review, the absence of these factors may weigh against admission.410

3. Error rate and professional standards

Daubert also indicates that the court should consider "the known or potential rate of error . . . and the existence and maintenance of standards controlling the technique's operation."411 The courts have overemphasized this factor in a number of cases by treating an indeterminate error rate as conclusive in circumstances where it should have little bearing.412 A recent decision in which a district court issued a protective order against the administration of a battery of psychological tests as part of a mental status exam of a plaintiff who claimed to be suffering from depression as a result of experiencing sex discrimination in employment illustrates this point.413 The plaintiff "adduced substantial information demonstrating the inadequacy of the correlation factors and the validity factors of all five of the tests in question."414 Under these circumstances, the court viewed the error rate of the proposed tests as indicating a lack of good cause for this aspect of the exam.415 Similarly, in the mentally retarded children's abuse case, the unknown error rate of the experts' methodology for determining abuse contributed to the magistrate's decision to exclude the evidence.416

On the other hand, an unknown error rate may not prove fatal to techniques previously admitted under Frye. The district court in a case involving questioned records offered to support a damage claim for sex harassment and retaliatory discharge stated that error rates are only one factor to consider in determining the admissibility of expert testimony and denied plaintiff's motion to exclude evidence from two chemical tests that were generally accepted for examining documents.417 Courts in civil rights cases have also considered noncompliance with standards in assessing the reliability of various techniques. In a number of cases, the courts have excluded expert evidence based on flawed statistics.418 In the abuse case, the magistrate expressed concern that protocol for interviewing mentally retarded children had not been followed and that there was no validated protocol for using anatomically correct dolls, art, or graphic materials as part of the protocol.419 Of course, the degree of compliance with the standards may significantly affect the court's determination of admissibility.420 4. General acceptance

Daubert's retention of Frye's general acceptance standard as a factor in gatekeeping greatly moderates the effect of the decision.421 In the civil rights area, as elsewhere, Daubert affords discretion to accept established theories and techniques, regardless of how they would fare if scrutinized in the first instance under the other gatekeeping factors. The decision thus anchors the gate to the future of expert evidence firmly in its past.

To date, no court in a civil rights case has excluded evidence previously found to have achieved general acceptance,422 and the courts have uniformly excluded proof which previously lacked general acceptance.423 Time will no doubt alter this trend, particularly as courts have occasion to grapple with truly novel theories which have not yet had extensive exposure in their respective disciplines. A party offering a novel theory, however, should be prepared to present convincing proof that the theory has a basis in good science as required by Daubert.424

C. Federal Rule of Evidence 703

Daubert instructs the district courts to "be mindful of other applicable rules."425 Among these is Rule 703 providing that "expert opinions based on otherwise inadmissible hearsay are to be admitted only if the facts or data are of a type reasonably relied upon by experts in the particular field in forming opinions or inferences uponthe subject."426 This requirement proved fatal in a civil rights case in which a pro se plaintiff attempted to introduce statistical evidence in support of a constitutional challenge to the Veterans Administration's (VA) claim procedures.427 On summary judgment, plaintiff offered the affidavit of another individual stating that numerical statistics provided by the VA had been analyzed using a certain computer program.428 The court found that there was no showing that the affiant was qualified as an expert or that the data was of a type reasonably relied on in the field and excluded the affidavit.429 By contrast, in a sexual harassment case in which plaintiff filed a motion in limine to bar the use of chemical tests to show that certain documents were not authentic, the district court summarily rejected a Rule 703 objection where substantial evidence showed that the underlying chemical tests were "reasonably relied upon by document experts."430

D. Federal Rule of Evidence 706

Daubert also directs the district court to keep in mind Rule 706, which permits the court to appoint its own expert to assist with the evaluation of expert evidence.431 Under this rule, the court-appointed expert must advise the parties of any findings and is subject to discovery by way of deposition.432 The court's expert may also be called to testify and be cross-examined at trial.433 Under Frye, some federal courts had found this option helpful in assessing the admissibility of expert evidence.434 Given the broader issues to be addressed under Daubert, such experts might substantially assist the court. The most significant obstacle to the use of this procedure in civil rights cases, which frequently involve parties with unequal resources, is the expense.435 The rule provides that the expert is entitled to reasonable compensation paid by the parties in such proportion as the court directs and taxed as costs of the litigation at the conclusion of the case.436 Should the court wish to make an appointment, this problem may be mitigated by an apportionment of the initial payment to the party that is able to afford it, subject to taxation as costs at the conclusion of the case.437 E. Federal Rule of Evidence 403

Daubert also directs the district court to take into account Rule 403 which affords discretion to exclude expert testimony where its "probative value is substantially outweighed by the 'danger of unfair prejudice, confusion of the issues, or misleading the jury.'"438 In part, this test involves a determination of whether the trier of fact is "properly equipped to judge the probative worth of the evidence."439 A sensitive application of the rule requires the court to consider carefully whether the "traditional and appropriate means of attacking shaky but admissible evidence"440 afford sufficient safeguards against these risks.

When considering lay testimony, the courts have wide discretion to balance probative value against possible prejudice under Rule 403.441 Because of the perception that expert testimony is morelikely to mislead, Daubert arms the district courts with broader discretion to exclude expert than lay testimony.442 Since Daubert, several courts have relied on this authority to hold inadmissible expert testimony which they viewed as having doubtful reliability.443 On the other hand, where the courts have adjudged the expert testimony relatively probative and reliable, they have generally overruled challenges based on Rule 403.444

Because civil rights cases involve basic personal rights and issues of social justice, the district court should favor admitting novel expert evidence under the Rule 403 test. This consideration, taken with the fact that the evidence must have at least some probative value in order to qualify for balancing under the rule, should cause the district court to explore all available avenues to allow the presentation ofnovel expert proof.445 These avenues may include traditional means, such as vigorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof, and non-traditional means, as suggested in the next section.

F. Attacking Shaky but Admissible Evidence: Cross-examination, Contrary Evidence, and Jury Instructions

Daubert identifies "[v]igorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof as the traditional and appropriate means of attacking shaky but admissible evidence."446 District courts have applied this principle in a variety of civil rights cases. In a due process case contesting the dismissal of a police officer, the court refused to exclude the testimony of a former police chief.447 The district judge expressed the view that a qualified expert should be permitted to testify with the burden on the opposing party to explore the basis for the testimony during cross-examination.448 The fact that the "'expert's testimony may be tentative or even speculative does not mean that the testimony must be excluded so long as opposing counsel has an opportunity to attack the expert's credibility.'"449

Another court refused to exclude the testimony of an ophthalmologist in a handicap discrimination case.450 The district judge noted, "Even if defendant finds that the expert's testimony is not very convincing, it is not sufficient ground to eliminate it under the scope of Rule 702."451 Instead, citing Daubert, the court found the traditional means of attacking testimony, including cross-examination, presentation of opposing evidence, and appropriate instruction by the court, to be sufficient.452 Still another court allowed statistical evidence of age discrimination notwithstanding objections to thecalculations, because the defendant, if dissatisfied, could critique the expert's method during crossexamination.453 In many circumstances, cross-examination will suffice to safeguard the truth-seeking process. The Supreme Court recently expressed this view in Barefoot v. Estelle.454 Declining to establish due process minimum for the reliability of psychiatric testimony regarding future danger posed to society by a defendant in a capital case, the Court stated:
[T]he rules of evidence generally extant at the federal and state levels anticipate that relevant, unprivileged evidence should be admitted and its weight left to the fact finder, who would have the benefit of cross-examination and contrary evidence by the opposing party.455

Under the Federal Rules of Evidence, a cross-examiner may require experts to disclose in detail the underlying facts and data for their opinion.456 Under these circumstances, a party offering the testimony of a purveyor of junk science risks a "devastating cross-examination."457 Such an examination requires effective preparation.458 Certainly the 1993 amendments to the Federal Rules of Civil Procedure mandating disclosure of detailed expert reports should facilitate preparation for cross-examination.459 Moreover, in federal court, a further protection exists in the time-honored practice of allowing the judge to question witnesses called by the parties inorder to assist the fact finder's assessment of confusing or misleading evidence.460

Occasionally, however, cases may arise in which a court believes that cross-examination will be ineffective in revealing the true credibility of the evidence. This may occur where there are neither generally accepted principles nor any other reasonably ascertainable basis for the expert's findings. In the mentally retarded children's abuse case, the magistrate, while not expressly referring to Rule 403, considered these factors and concluded the risk was too great:
[E]ven though the defendants may be able to discredit several of the indicators, symptoms or test results, the expert's overall opinion is likely to emerge unscathed. An expert using this methodology may candidly acknowledge any inconsistencies or potential shortcomings in the individual pieces of evidence she presents, but can easily dismiss the critique by saying that her evaluation relies on no one symptom or indicator and that her conclusions still hold true in light of all the other available factors and her expertise in the field. In such a case, the expert's conclusions are as impenetrable as they are unverifiable.461

In addition to the potential for effective cross-examination, Daubert requires the court to consider the effect of other evidence.462 This may include both the expert evidence presented by the opposing party463 and any testimony offered by a court-appointed expert.464 The court may also consider the availability of lay witnesses. In the mentally retarded children's abuse case, the magistrate cited the inability of children to testify to support the exclusion of expert testimony.465 On the other hand, a context of lay evidence on anissue, be it opposing or corroborating, supports the admission of more questionable expert testimony. Juries (and to some extent judges) may discount expert evidence where other evidence exists because they find the lay evidence more familiar and tend to view experts as cosmetic witnesses or hired guns.466 The availability of other sources of evidence substantially mitigates the potential for expert evidence to mislead and should favor its admission.

A further protection noted in Daubert is proper instruction of the jury.467 Normally a judge instructs that the testimony of an expert is evaluated like that of any other witness, and the jury is free to reject the testimony entirely if it is not credible.468 While today's juries may sometimes have difficulty understanding their instructions, they maintain a healthy skepticism of expert testimony and comply with the intent of the standard instruction.469 Appropriate instruction is an effective means to ensure the integrity of fact finding and, with cross-examination and presentation of related evidence, will support the admission of expert testimony despite strenuous objections in many cases.470

VI. Suggestions for Addressing Novel Expert Evidence in Federal Civil Rights Actions

A. Utilization of the Federal Judicial Center Manual

The 1994 publication of the Reference Manual on Scientific Evidence (F.J.C. Manual) by the Federal Judicial Center (F.J.C.)471 is a noteworthy post-Daubert development with potential significance for civil rights cases. F.J.C. Director Judge William H. Schwarzer stated that the manual was intended "to help judges understand basic concepts--the analytical framework--of certain sciences and the Rules of Evidence and to identify issues relevant to the admissibility of evidence."472 The book contains seven chapters describing various scientific methodologies,473 a list of peer reviewers for experts in various fields,474 and additional chapters on the management of expert evidence, court-appointed experts, and special masters.475 In addition, the manual includes a chapter by Professor Margaret Berger entitled "Evidentiary Framework," which addresses relevant aspects of the law of evidence.476

The manual should serve as a cost-effective source of assistance in defining certain scientific issues and understanding their substance and proof. In some cases, the manual may provide sufficient common ground between parties to allow stipulations on at least preliminary matters of expert evidence.477 Depending on the subject matter at issue, the manual may also support requests for judicial notice of settled scientific principles.478 The utility of this manual has yet to be determined.479 While the F.J.C. published the manual for the judiciary, it remains to be seen whether heavily burdened district court judges, who for the most part are generalists,480 will undertake significant additional responsibility for the assessment of scientific evidence based on the availability of the manual.481 Instead, as our adversarial system assumes, the parties will likely provide the primary impetus for the manual's use, while judges will continue to seek assistance from other sources.

B. Appointment of a Special Master

The appointment of a special master may be helpful in those civil rights cases which present extremely difficult gatekeeping issues.482 Federal Rule of Civil Procedure 53 empowers a special master to conduct proceedings and make a written report to the court.483 Rule 53 expressly authorizes a special master to rule on the admissibility of evidence.484

Appointments, however, are disfavored under the Rule. In jury cases, the court may appoint a master "only when the issues are complicated;" in cases to be tried to the bench, the court may make an appointment only where "some exceptional condition requires it."485 Such circumstances might be present where gatekeeping issues are so theoretical, technical, or complex that the court finds itself unable to address them in the first instance. Courts handling complex civil rights cases have occasionally appointed masters to assist with other issues.486

District courts considering the appointment of a special master for gatekeeping may wish to examine the cases under the National Childhood Vaccine Injury Act,487 where special masters have proven useful in assessing the validity of scientific evidence using the Daubert standard.488 The experience in these cases suggests that a special master familiar with the relevant field might significantly assist the court.

Appointments of masters, however, are sometimes controversial. Parties may object to appointments based on the potential for delay and expense.489 They may also claim that the appointment is a denial of their right to a jury trial under the Seventh Amendment490 or to a decision by a judge appointed under Article III of the Constitution.491 The use of a special master for the limited purpose suggested here should minimize these concerns. Given the likelihood that gatekeeping will consume significant amounts of court time,492 the use of a special master to hear a motion in limine may expedite both the hearing and the ultimate resolution on the merits.493 Confining the special master's undertaking to these tasks should minimize expense and, as with Rule 706, the court could mitigate problems associated with fees by allocating them initially to one party.494 Finally, because gatekeeping involves the exercise of the court's discretion,495 the use of a special master would not affect the right to a jury trial and would minimally impact the right to a decision by an Article III judge, inasmuch as the district court would (except for any subsidiary findings of fact subject to review under a clearly erroneous standard) determine the admissibility of the expert evidence de novo.496 C. Utilization of a Technical Advisor

A technical advisor may also provide significant assistance with gatekeeping in civil rights cases. In addition to the authority to appoint an expert under Rule 706 or a special master under Rule 53, a district court has inherent power to obtain such technical assistance as is necessary to the performance of its duties.497 A court may exercise this power in cases where specialized knowledge is needed to resolve "problems of unusual difficulty, sophistication, and complexity, involving something well beyond the regular questions of fact and law with which judges must routinely grapple."498 Thus, the Sixth Circuit approved the appointment of a nationally recognized expert on school administration to advise a special master on educational issues in school desegregation.499

The use of a technical advisor offers advantages of informality and flexibility in procedures. The selection and use of an advisor is not governed by Federal Rule of Evidence 706.500 Advisors do not make findings within the meaning of Rule 706, are not subject to deposition, and do not testify at trial.501 For these reasons, the court may find it easier to recruit persons to serve in this capacity than as experts.502 Unlike a special master, who conducts proceedings and reports to the court under Federal Rule of Civil Procedure 53, an advisor is simply a "sounding board" for the court.503 On the other hand, the court has no authority to order the parties to pay advisor fees and to tax these amounts as costs. Courts which have used technical advisors have thus either secured the parties' agreement to pay fees or sought assistance from the Administrative Office of the United States Courts, which has authorized reimbursement in cases where appointment of an expert under Federal Rule of Evidence 706 or a master under Federal Rule of Civil Procedure 53 was not appropriate.504

In light of the informality of this procedure and its limited accountability in the adversary process, courts have narrowly defined the tasks of technical advisors. One such use is the interpretation of specific testimony or data for the court.505 Another is the provision of background knowledge to the court. A district court in a patent infringement case described the advisor's role in a manner suggestive of its utility for gatekeeping after Daubert:
A busy trial court faced with complex technology may require independent education or analysis if it is to understand the technology before the trial. The parties nominated Dr. Vacroux and agreed that he is an independent expert. If a motion for summary judgment appears to have merit a court will need some education about the technology at an earlier stage of the proceedings but it will not need independent findings. That is this case. What was sought here was an independent explanation of the technology and assistance in understanding the positions of the parties' experts.506

A district court may welcome such assistance. A technical advisor may help the court understand expert evidence to determine its relevance. An advisor may provide similar assistance with respect to the determination of reliability, including the assessment of testing, peer review and publication, error rate and professional standards, general acceptance in a particular field, and other factors as applicable. The advisor can participate at any of the stages in which such Daubert issues arise. The court can tailor the advisor's role to the needs of the specific case while avoiding the procedural encumbrances involved in the use of court-appointed experts or special masters.507

Moreover, the role of advisor need not be restricted to assisting with gatekeeping. An advisor may assist with case management to facilitate the utilization of novel expert testimony in a civil rights case. The assistance may include explaining a novel expert issue raised at a scheduling or a pretrial conference and aiding the court in assessing proposed discovery or plans to develop evidence during the litigation, as in Brown.508 In addition, the advisor may help develop any special procedures that the court may require. The advisor may assist the court in understanding expert proof in relation to other evidence for purposes of the Rule 403 determination as to whether an opponent of expert testimony can challenge it by traditional means. Consultation on the phrasing of jury instructions regarding expert proof is another way an advisor might aid the court. Finally, an advisor might simply assist the court in understanding the F.J.C. Manual or advise the court regarding the appointment of an expert or master.

D. Special Procedures

In addition, district courts should consider the implementation in civil rights cases of special procedures authorized by Federal Rule of Civil Procedure 16(c)(12) to address "complex issues" and "unusual proof problems."509 Particularly in cases where expert proof is so complex that it may exceed the comprehension of the trier of fact and be subject to exclusion under Rule 403, the court should consider some modification of the adversary process to facilitate the presentation of evidence in an understandable manner.

One suggestion is to teach the fact finder basic principles of the relevant field before the experts testify. The analogy of expert testimony to education has often been noted.510 Common sense and experience indicate that adversary presentation of expert evidence does not always serve this purpose well.511 A judicially supervised presentation of basic expert principles may provide significant assistance in extremely complex cases.512 While stipulations are the traditional means of presenting agreed testimony or background matter, their effect is sometimes mind-numbing, even when they do not involve technical matter. The educational purpose is better served by having a teacher provide a narrative. Such a presentation could be made by the court's expert or, with the agreement of the parties, the court's technical advisor.

The court should introduce the procedure with an explanation of its purpose and content. The court should then provide a preliminary statement of the expert issues in order to supply necessary context.513 The presentation would follow with a basic introduction to the scientific, technical, or other expert principles at issue. The presentation should stress clarity of expression, include graphics, and minimize reliance on technical jargon, which is perhaps the primary impediment to juror comprehension.514 The court should settle the scope of the presentation and any objections in advance so that the presentation may occur without cross-examination or other interruption by the parties.515 Properly handled, this procedure could maximize the trier of fact's capacity to deal with expert testimony in civil rights cases. It should also minimize the exclusion of evidence under Rule 403 and thereby serve the important societal interest in resolving these claims on the merits.


Beginning with the landmark case of Brown v. Board of Education, there has been a dramatic increase in the use of expert evidence in federal civil rights litigation. The proliferation of expert proof, often novel in nature, has not gone unchallenged. Federal civil rights cases today account for a significant percentage of the citations to the U.S. Supreme Court decision two years ago in Daubert v. Merrell Dow Pharmaceuticals, Inc., directing district courts to exercise discretion as gatekeepers to ensure that scientific evidence is both relevant and reliable.

Because civil rights actions assert basic personal rights and often raise broad social justice issues, the district courts should incline toward admitting novel expert evidence to facilitate the resolution of these cases on the merits. The courts should explore all available methods, including non-traditional means, to allow the presentation of novel expert proof. Suggested non-traditional approaches include utilization of the F.J.C.'s newly published Reference Manual on Scientific Evidence, appointment of a special master, use of technical advisors, and implementation of special procedures including non-adversary presentation of expert testimony. These procedures should enhance the court's capacity to admit and assimilate novel expert evidence in civil rights cases.