Reference Manual on Scientific Evidence Third Edition (2011) / Chapter Skim
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The Admissibility of Expert Testimony--Margaret A. Berger
The Admissibility of Expert Testimony--Margaret A. Berger
Pages 11-36
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From page 11... ...
25 IV. Forensic Science, 26 A. Validity, 27 B. Proficiency, 28 C. Malfunctioning Laboratories, 28 D. Interpretation, 29 E. Testimony, 29 F. Assistance for the Defense and Judges, 29 G. Confrontation Clause, 30 V. Procedural Context, 30 A. Class Certification Proceedings, 30 B. Discovery, 32 1.
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From page 12... ...
First, it recognized the trial judge as the "gatekeeper" who must screen proffered expert testimony.6 Second, the objective of the screening is to ensure that expert testimony, in order to be admissible, must be "not only relevant, but reliable."7 Although there was nothing particularly novel about the Supreme Court finding that a trial judge has the power to make an admissibility determination -- Federal Rules of Evidence 104(a) and 702 pointed to such a conclusion -- and federal trial judges had excluded expert testimony long before 1. 509 U.S.
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From page 13... ...
It acknowledged that scientists typically distinguish between validity and reliability and that "[i] n a case involving scientific evidence, evidentiary reliability will be based upon scientific validity." Daubert, 509 U.S.
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From page 14... ...
The trial court applied the Daubert criteria, excluded the opinions of the plaintiff 's experts, and granted the defendants' motion for summary judgment.19 The court of appeals reversed the decision, stating that "[b] ecause the Federal Rules of Evidence governing expert testimony display a preference for admissibility, we apply a particularly stringent standard of review to the trial judge's exclusion of expert testimony."20 All the justices joined Chief Justice Rehnquist in holding that abuse of discretion is the correct standard for an appellate court to apply in reviewing a district court's evidentiary ruling, regardless of whether the ruling allowed or excluded expert testimony.21 The Court unequivocally rejected the suggestion that a more stringent standard is permissible when the ruling, as in Joiner, is "outcome determinative" because it resulted in a grant of summary judgment for the defendant because the plaintiff failed to produce evidence of causation.22 In a concurring opinion, Justice Breyer urged judges to avail themselves of techniques, such as the use of court-appointed experts, that would assist them in making determinations about the admissibility of complex scientific or technical evidence.23 18. 522 U.S.
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From page 15... ...
The Court noted that the plaintiff never explained "how and why the experts could have extrapolated their opinions"24 from animal studies far removed from the circumstances of the plaintiff 's exposure.25 It also observed that the district court could find that the four epidemiological studies the plaintiff relied on were insufficient as a basis for his experts' opinions.26 Consequently, the court of appeals had erred in reversing the district court's determination that the studies relied on by the plaintiff 's experts "were not sufficient, whether individually or in combination, to support their conclusions that Joiner's exposure to PCBs contributed to his cancer."27 The plaintiff in Joiner had argued that the epidemiological studies showed a link between PCBs and cancer if the results of all the studies were pooled, and that this weight-of-the-evidence methodology was reliable. Therefore, according to the plaintiff, the district court erred when it excluded a conclusion based on a scientifically reliable methodology because it thereby violated the Court's precept in Daubert that the "focus, of course, must be solely on principles and methodology, not on the conclusions that they generate."28 The Supreme Court responded to this argument by stating that conclusions and methodology are not entirely distinct from one another.
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From page 16... ...
v. Carmichael Less than one year after deciding Joiner, the Supreme Court granted certiorari in Kumho to decide if the trial judge's gatekeeping obligation under Daubert applies only to scientific evidence or if it extends to proffers of "technical, or other specialized knowledge," the other categories of expertise recognized in Federal Rule of Evidence 702.
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From page 17... ...
. matters within its scope."39 Furthermore, said the Court, "no clear line" can be drawn between the different kinds of knowledge, and "no one denies that an expert might draw a conclusion from a set of observations based on extensive and specialized experience."40 The Court also unanimously found that the court of appeals had erred when it used a de novo standard, instead of the Joiner abuse-of-discretion standard, to determine that Daubert's criteria were not reasonable measures of the reliability of the expert's testimony.41 As in Joiner, and again over the dissent of Justice Stevens,42 the Court then examined the record and concluded that the trial court had not abused its discretion when it excluded the testimony of the witness.
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From page 18... ...
Marley,48 the district court ruled for plaintiffs on a Daubert motion and the plaintiffs won a jury verdict. On appeal, the circuit court found that, despite the abuse-of-discretion standard, plaintiff 's experts should have been excluded and granted judgment as a matter of law for the defendants.
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From page 19... ...
Should they pay for additional expensive expert testimony even though they think the district court would rule in their favor on a Daubert motion, or is the risk of a reversal on Daubert grounds and a consequent judgment for the defendant too great despite the abuse-of-discretion standard? Weisgram may indeed push plaintiffs to bring the very best expertise into litigation -- a stated goal of the trilogy, but it may also make it difficult to litigate legitimate claims because of the cost of expert testimony.
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From page 20... ...
As Daubert recognizes, the trial judge's authority to decide whether the plaintiff has produced sufficient evidence to withstand a dispositive motion under Rule 56 or 50 is indisputable; a one-step process that considers sufficiency when adjudicating a Daubert motion is arguably 51. See e.g., Susan Haack, An Epistemologist in the Bramble-Bush: At the Supreme Court with Mr. Joiner, 26 J
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From page 21... ...
If the expert testified at trial, information that could have skewed the expert's testimony could be brought to the attention of the jury through cross-examination or extrinsic evidence. Impeachment by bias suffers from fewer constraints than other forms of impeachment.55 But suppose the defendant seeks through a Daubert challenge to exclude the plaintiff 's expert witness as relying on unreliable evidence to show causation in a toxic tort action.
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From page 22... ...
Greater Lafayette Health Serv. Inc.,58 a complex antitrust case, the court held that the trial court properly excluded the plaintiff 's economic experts on the ground that the plaintiff 's antitrust theory was based on the wrong legal standard after ruling for the plaintiff on Daubert challenges.
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From page 23... ...
But even when there are epidemiological studies, a court may conclude that they cannot prove causation because they are not conclusive and therefore unreliable. And if they are unreliable, they cannot be combined with other evidence.60 Experts will often rely on multiple studies, each of which has some probative value but, when considered separately, cannot prove general causation.
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From page 24... ...
Epidemiological studies that are not conclusive but show some increased risk do not prove a lack of causation. Some courts find that they therefore have some probative value,62 at least in proving general causation.63 Even, however, if plaintiffs convince the trial judge that their experts relied on reliable and relevant evidence in establishing general causation, that is, in opining that the defendant's product can cause the adverse effects for which plaintiffs seek compensation, plaintiffs must also present admissible expert testimony that the defendant's product caused their specific injuries.
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From page 25... ...
2001) (affirming jury verdict that exposure to solvent caused plaintiff 's psychological and cognitive impairment and Parkinsonian symptoms; defendant argued that expert's opinion based on case reports, animal studies, structural analysis studies should have been excluded on Daubert grounds; the court stated: "The first several victims of a new toxic tort should not be barred from having their day in court simply because the medical literature, which will eventually show the connection between the victims' condition and the toxic substance, has not yet been completed.")
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From page 26... ...
IV. Forensic Science To date, Daubert has rarely been raised in the forensic context, but this may be about to change.74 We do not know as yet what shifts may occur in response to the National Academies' highly critical report on the forensic sciences.75 We do know that the report played a role in the Supreme Court's opinion in Melendez with levels of harm -- plaintiff must only produce evidence from which a reasonable person could conclude that the defendant's emissions probably caused the plaintiff 's harms.")
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From page 27... ...
To date, however, few prosecution experts have been excluded as witnesses in criminal prosecutions.78 Usually judges have allowed them to testify or, at most, have curtailed some of the conclusions that prosecution experts sought to offer.79 However, there are a number of issues in forensic sciences that may become the object of Daubert challenges.
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From page 28... ...
81. Specific forensic science techniques are discussed in Paul C Giannelli et al., Reference Guide on Forensic Identification Expertise, Sections V–X, in this manual.
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From page 29... ...
Whether a defendant in a particular case is constitutionally entitled to expert assistance is a complicated issue that defense counsel needs to explore.85 Possibly the best chance for the defense to get meaningful help that also would assist the court is to get pro bono assistance 84. National Research Council, supra note 75, at 184–185.
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From page 30... ...
Numerous unanswered questions about the operation of Melendez-Diaz will have to be litigated. It remains to be seen how often, if at all, defense counsel will take advantage of the Confrontation Clause or whether they will waive the defendant's right to confront expert witnesses.87 V
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From page 31... ...
Daubert challenges have been raised to class certification in numerous other cases.91 As of this writing, there is a decided trend toward rejecting class certification on the ground that plaintiff 's proffered expert testimony does not satisfy the Rule 23(a) requirements, although the circuits are not unanimous in how rigorous the examination of expert proof needs to be.
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From page 32... ...
09-1403) , which raises related questions regarding the extent to which the district court may consider the merits of the underlying litigation and require that loss causation be demonstrated by a preponderance of admissible evidence at the class certification stage under Federal Rule of Civil Procedure 23. Other courts accord Daubert a limited role, such as requiring the trial judge to determine only that the expert testimony is "not fatally flawed." See Fogarazzo v.
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From page 33... ...
After a series of public hearings the Advisory Committee on Civil Rules determined that the disclosure rules increased the cost of litigation with no offsetting advantage to the conduct of litigation. The report of the Advisory Committee noted that such an extensive inquiry into expert communications with attorneys did not lead to better testing of expert opinions "because attorneys and expert witnesses go to great lengths to forestall discovery."100 Under amended rules that became effective in December 2010, disclosure is limited to "the facts or data" considered by the expert, and does not extend to "other information." Draft reports are no longer discoverable, and communications between counsel and an expert are protected from discovery unless the communications: (1)
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From page 34... ...
identify assumptions furnished by counsel that the expert relied upon in forming opinions. Testifying experts who were not required to provide a report under the previous rules -- such as treating physicians -- are now required to provide a summary of the facts or opinions to which the witness expects to testify.While this requirement relating to experts not required to file a report would provide more disclosure than under the 1993 amendments, the main thrust of the 2010 amendments is to narrow expert discovery with an eye toward minimizing expense and focusing attention on the expert's opinion.
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From page 35... ...
The defendant claimed that the trial judge erred in granting the government's Daubert motion to exclude his expert in the middle of the trial without an evidentiary hearing, leading to his conviction. On appeal, a divided panel of the Tenth Circuit reversed on the ground that the expert testimony had been improperly excluded and remanded for a new trial.
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From page 36... ...
Moreover, there are serious concerns about whether the guidelines enunciated by the Court have been interpreted by lower courts to limit, rather than respect, the discretion of trial judges to manage their complex cases, whether the guidelines conflict with the preference for admissibility contained in both the Federal Rules of Evidence and Daubert itself, and whether the guidelines have resulted in trial judges encroaching on the province of the jury to decide highly contested factual issues and to judge the overall credibility of expert witnesses and their scientific theories. Perhaps most disturbingly, there are serious concerns on the part of many scientists as to whether the courts are, as Daubert prescribed, making admissibility decisions -- decisions that may well determine the ultimate outcome of a case -- which are in fact "ground[ed]
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