Introduction
     Scientific evidence and expert testimony have the potential for affecting the outcomes in hundreds, if not thousands, of criminal and civil cases. Courts continue to search for the balance between allowing each party its day in court and taking into account the work which other courts have already done in determining the admissibility of an expert witness' testimony. When a Daubert challenge arises, it is often the case that other courts have addressed the same issue, often in hearings involving the same experts. Trial judges facing such challenges want to know whether they must hold a new Daubert hearing and deal with the issue from scratch, or whether they can in some way avoid the need to reinvent the wheel.
 

Judicial Notice of Previous Decisions
     While a court can take notice of facts that are "truisms that approach platitudes or banalities,"⁽¹⁾ the situation becomes more problematic when the question is not firmly settled and is the ultimate issue in the litigation. As noted in Castillo-Villagra v. Immigration and Naturalization Service, "the administrative desirability of notice as a substitute for evidence cannot be allowed to outweigh fairness to individual litigants."⁽²⁾ At the same time, nothing stops a court from noticing what previous courts have decided during the course of a Rule 104(a) hearing.⁽³⁾ Thus, while it would probably be improper for a court to notice the proposition "Bendectin does not cause birth defects," it would be acceptable to notice that the court in Daubert on remand chose to exclude expert testimony either in support of or in contrast to its own conclusion. Thus, it appears that courts can apply precedential reasoning or use judicial notice to evaluate expert testimony in civil trials.

Following Precedent: The Daubert Cases Themselves
     Although some thought that the Daubert Supreme Court decision would eliminate the use of precedent in evidence decisions entirely⁽⁴⁾, Daubert on remand to the Ninth Circuit shows that courts still can take judicial notice of or otherwise take into account admissibility rulings in other jurisdictions.

     The trial court opinion in Daubert, written by Judge Earl Gilliam, uses precedent extensively to support its conclusion that the plaintiff's experts should be excluded and summary judgment for the defendants should be granted.⁽⁵⁾ Not only did the opinion refer to the general consensus of other courts, but in one paragraph the opinion string-cites opinions from the First Circuit, the Sixth Circuit, trial courts in New Jersey and Florida, and the consolidated litigation in Ohio to provide support for its admissibility ruling.⁽⁶⁾ It also substantially relies on Brock v. Merrell Dow Pharmaceuticals,⁽⁷⁾ quoting a paragraph on the insufficiency of the plaintiff's evidence.⁽⁸⁾ While the opinion does note a D.C. Circuit opinion to support the plaintiff's position on admitting the experts,⁽⁹⁾ the court dismissed it as "definitely in the minority camp."⁽¹⁰⁾

     When the case was appealed to the Ninth Circuit,⁽¹¹⁾ Judge Kozinski echoed some of the precedential reasoning from the lower court opinion. At the start, the opinion notes that Bendectin "is not a new question in the federal courts[;] ... four of our sister circuits have considered whether plaintiffs could establish such responsibility in the absence of critically analyzed epidemiological studies establishing a connection between the use of the drug and the birth defects."⁽¹²⁾ It also uses the fact that "Richardson⁽¹³⁾ and Lynch⁽¹⁴⁾ held that expert testimony that Bendectin caused birth defects, based solely on animal and chemical tests and reanalysis of epidemiological studies, was inadmissible" as support for its own conclusion.⁽¹⁵⁾

     On remand, the Ninth Circuit focused on the individuals the plaintiff offered as experts and discredited them by reference to earlier opinions.⁽¹⁶⁾ For example, the Court states that "Dr. Palmer offers no tested or testable theory to explain how... he was able to eliminate all other potential causes of birth defects[;] ... we therefore agree with the Sixth Circuit's observation⁽¹⁷⁾ that '...no understandable scientific basis is stated.'"⁽¹⁸⁾ The opinion ends with another string-cite, this time in a footnote, to similar decisions in other jurisdictions.⁽¹⁹⁾

     Joseph Sander's thorough statistical analysis of the opinions in the Bendectin litigation concludes that the precedential reasoning apparent in these cases is quite typical of Bendectin cases in general.⁽²⁰⁾ When these cases were first brought, judges were more likely to use procedural devices to "streamline" the litigation process, but after a number of cases were tried, the courts were more likely to use procedure to "dispose of cases on their merits."⁽²¹⁾

Post-Daubert Cases Which Follow Precedent
     As Samuel Gross has observed, the change from the Frye test to Daubert may not have as large an impact as anticipated, because judges "decide whether to admit scientific evidence not by determining global facts... nor by weighing factors pro and con... but by referring to specific governing precedents."⁽²²⁾ Since Daubert II, a number of courts have referred to other post-Daubert precedents as a basis for their own admissibility rulings. In Lust v. Merrell Dow⁽²³⁾ the Ninth Circuit considered a claim that a drug had caused a type of birth defect. The trial court excluded the testimony of a plaintiff's expert based on the fact that he had "merely interpreted the work of others," and that no published study supported his conclusions.⁽²⁴⁾ It was noted that that his opinions had been formulated "in preparation for expert testimony in a different case concerning a different drug manufactured by Merrell Dow" and had been excluded previously in the Bendectin litigation.⁽²⁵⁾

     A final post-Daubert example of precedential reasoning can be found in Rutigliano v. Valley Business Forms.⁽²⁶⁾ The court in that case excluded the plaintiff's expert testimony. The court supported its exclusion criteria by referencing other decisions that used similar grounds. For excluding data "reanalysis," the Court cites an earlier case from the Third Circuit, Wade-Greaux v. Whitehall Laboratories.⁽²⁷⁾ For the need to "eliminate alternative explanations for the plaintiff's illness,"⁽²⁸⁾ the earlier decision in Diaz v. Johnson Matthey⁽²⁹⁾ was cited. As these post-Daubert cases show, some courts do take other cases into account when making their own admissibility holdings.

Post-Daubert Cases: The Courts that "Go Their Own Way"
     A significant number of courts have decided that they want to "go their own way," developing their own analysis of admissibility despite the rulings of other courts. In doing so, some courts have mentioned previous decisions, only to distinguish them from the current case they are considering. In others, the courts simply ignore the presence of contrary decisions.

     In both Becker v. National Health Products⁽³⁰⁾ and Benedi v. McNeil⁽³¹⁾, precedential value was not given to the decisions of earlier courts. While the specific claims were different, the plaintiffs relied on differential clinical diagnosis to establish general causation in both. Numerous courts have held that clinical opinions used solely to prove general causation are inadmissible,⁽³²⁾ but the courts in Becker and Benedi allowed the experts to testify. Neither opinion mentions these countervailing earlier decisions.

     Only a few courts that have decided differently from post-Daubert precedents have cited those cases to distinguish their decision. In Hall v. Baxter Healthcare Corp., an expert who had been ruled admissible in Hopkins v. Dow Corning⁽³³⁾ was excluded. The court differentiated Hopkins by pointing out that its trial occurred before Daubert, and that other evidence supporting general causation was present that had been barred in Hall.⁽³⁴⁾ While these distinctions may not be convincing, Hall does make an effort to reconcile the cases.

    Similarly, in In re Orthopedic Bone⁽³⁵⁾, the Court decided to admit expert testimony which was partially based on reanalysis of studies which had reached opposite conclusions. While the court cites the Wade-Greaux and Diaz opinions, it states that because this particular expert "brings his expertise in orthopedic bioengineering to bear" on the literature, his testimony should be admitted.⁽³⁶⁾ Thus, although some courts have taken the decisions of other courts into account in admissibility rulings, others would rather not do so. Part of the split over this subject may be due to the new admissibility test articulated in Daubert, as courts may be uncertain about which precedents survive that decision.

Daubert's Impact on Established Criminal Law Precedents
     While Daubert itself was a civil case, much of its impact has appeared in determining the admissibility of criminal evidence. Although Justice Blackmun noted in Daubert that "well-established propositions are less likely to be challenged than those that are novel,"⁽³⁷⁾ courts have been re-evaluating long-standing precedents about evidence ranging from hair fibers to handwriting analysis and eyewitness testimony. Many courts have concluded that, based on the current state of science, these precedents should no longer be followed.

     Evidence of hair fiber analysis, for example, has been accepted since the mid-1970s. The leading case, U.S. v. Brady, concluded that "the evidence had sufficient probative value to be admissible...[ t]he lack of certainty went to the weight to be assigned to the testimony of the expert, not its admissibility."⁽³⁸⁾ Although debate continued, because some judges felt that the lack of precision of hair evidence led to unjust verdicts⁽³⁹⁾ and the few available scientific studies indicated that some problems existed,⁽⁴⁰⁾ hair evidence has been routinely admitted. However, after Daubert, two courts have decided that the judicial gatekeeping function should be used to evaluate its admissibility, and neither believed that hair analysis was admissible without more scientific evidence of its accuracy and reliability⁽⁴¹⁾. The Williamson court noted that it "has been unsuccessful in its attempts to locate any indication that expert hair testimony meets any of the requirements of Daubert."⁽⁴²⁾

     While Daubert has been interpreted as mandating the exclusion of certain types of criminal evidence without more study, it also has been interpreted as mandating the inclusion of other types of evidence. For example, the Third Circuit in U.S. v. Velasquez⁽⁴³⁾ concluded that, despite judicial notice by the trial court of the reliability of handwriting analysis, testimony offered by a critic of that field should have been permitted. The Court concluded that, where the weight of an accepted type of evidence was at issue, a critical expert satisfying the Daubert criteria could not be excluded from testifying about its shortcomings.⁽⁴⁴⁾

     Federal courts have been divided on this issue. The First Circuit⁽⁴⁵⁾ and Ninth Circuit⁽⁴⁶⁾ have rejected such evidence in post-Daubert decisions but allowed the possibility that it might be admissible in the right circumstances to remain open. Citing those circumstances, a U.S. district court in the First Circuit recently admitted eyewitness-testimony impeachment evidence in U.S. v. Jordan.⁽⁴⁷⁾ Determinations about eyewitness evidence thus may have to be made on a case-by-case basis by judges. As the Daubert majority noted, "Scientific conclusions are subject to perpetual revision."⁽⁴⁸⁾

Conclusion
     Deciding whether or not to admit expert testimony may affect not only the evidence that goes to the jury in a given case but may also impact future cases through precedential effect. In making admissibility decisions, judges may have more to examine than just the facts and testimony at hand. They may also look to admissibility decisions made by courts in similar cases or with similar testimony. A judge must then choose to give weight to, distinguish, or ignore these previous decisions in reaching an admissibility decision in a Daubert hearing.

1. Hardy v. Johns Manville Sales Corp., 681 F.2d 334 at 347 (5th Cir. 1982).
2. 972 F.2d 1017 (9th Cir. 1992).
3. See generally Clifton T. Hutchinson and Julie E. Blend, Preclusion of Scientific Evidence after Daubert, 1 Shepards Expert And Scientific Evidence Quarterly 673 (1994).
4. Hao-Nhien Q. Vu and Richard A. Tamor, Of Daubert, Elvis, and Precedential Relevance: Live Sightings of a Dead Legal Doctrine, 41 UCLA L. Rev. 487, 499 (1993).
5. Daubert v. Merrell Dow Pharmaceuticals, 727 F. Supp. 570, 574 (S.D.Cal, 1989).
6. Id. at 572.
7. 874 F.2d 307 (5th Cir. 1989), modified, 884 F.2d 166 (5th Cir. 1989).
8 .727 F. Supp. at 572.
9. Oxendine v. Merrell Dow Pharmaceuticals, 506 A.2d 1100 (D.C. App. 1986).
10. 727 F. Supp. at 573.
11. Daubert v. Merrell Dow Pharmaceuticals, 951 F.2d 1128, 1130 (9th Cir. 1991) (hereinafter Daubert I).
12. Id. at 1130.
13. Richardson v. Richardson-Merrell, Inc., 857 F.2d 823 (D.C. Cir. 1988).
14. Lynch v. Merrell-National Labs., 830 F.2d 1190 (1st Cir. 1987).
15. 951 F. 2d at 1130.
16. Daubert v. Merrell Dow Pharmaceuticals, 43 F.3d 1311 (9th Cir. 1995) (hereinafter Daubert II).
17. The case the court is referring to is Turpin v. Merrell Dow Pharmaceuticals, Inc., 959 F.2d 1349,1360 (6th Circuit 1992).
18. Daubert II, 43 F.3d at 1319.
19. Id. at 1322, n.19.
20. See generally Joseph Sanders, The Bendectin Litigation: A Case Study in the Life Cycle of Mass Torts, 43 Hastings L.J. 301.
21. Id. at 372-373.
22. Samuel R. Gross, Substance and Form in Scientific Evidence: What Daubert Didn't Do in Reforming The Civil Justice System 234, 245 (Larry Kramer, Ed., 1996).
23. 89 F.3d 594 (9th Cir. 1996).
24. Id. at 596.
25. Id. at 596.
26. 929 F. Supp. 779 (D.N.J. 1996).
27. 874 F. Supp 1441 (D.V.I. 1994), aff'd 46 F. 3d 1120 (3d Cir. 1994).
28. 929 F. Supp. at 786.
29. 893 F. Supp. 358 (D.N.J. 1995)
30. 896 F. Supp. 100 (N.D.N.Y. 1995).
31. 66 F. 3d 1378 (4th Cir. 1995).
32. See Hall v. Baxter Healthcare Corp. 1996 WL 730693, 20 (D.Or. 1996), (listing a number of cases where courts have excluded differential clinical diagnosis offered to prove general causation).
33. 33 F.3d 1116 (9th Cir. 1994).
34. 1996 WL 730693, 21.
35. In re Orthopedic Bone Screw Products Liability Litigation, 1997 WL 39583 (E.D. Pa.).
36. Id., at 5.
37. 509 U.S. 579, 593 n.11.
38. 595 F.2d 359, 363.
39. See, for example, the dissent of Cavanaugh, C.J. in People v. Kosters, 467 N.W.2d 311 (Mich. 1991).
40. Williamson v. Reynolds, 904 F.Supp. 1529, 1556 (E.D.Okl. 1995).
41. Id. See also McGrew v. State, 673 N.E.2d 787 (Ind.App. 1996).
42. 904 F.Supp. at 1558.
43. 64 F.3d 844 (3d Cir. 1995).
44. Id. at 850.
45. U.S. v. Brien, 59 F.3d 274 (1995), cert. denied 115 S.Ct. 1263 (1995).
46. U.S. v. Rincon, 28 F.3d 921 (1994), cert. denied 115 S.Ct. 605 (1994)
47. 924 F.Supp. 443 (W.D.N.Y. 1996).
48. 509 U.S. at 597.