3
The Admission of Forensic Science Evidence in Litigation

This chapter describes the legal system’s reliance on forensic science evidence in criminal prosecutions and examines the existing adversarial process for admitting this type of evidence. The report describes and analyzes the current situation and makes recommendations for the future. No judgment is made about past convictions and no view is expressed as to whether courts should reassess cases that already have been tried. The report finds that the existing legal regime—including the rules governing the admissibility of forensic evidence, the applicable standards governing appellate review of trial court decisions, the limitations of the adversary process, and judges and lawyers who often lack the scientific expertise necessary to comprehend and evaluate forensic evidence—is inadequate to the task of curing the documented ills of the forensic science disciplines. This matters a great deal, because “forensic science is but the handmaiden of the legal system.”1 As explained in Chapters 4 and 5, there are serious issues regarding the capacity and quality of the current forensic science system; yet, the courts continue to rely on forensic evidence without fully understanding and addressing the limitations of different forensic science disciplines. This profound conjunction of law and science, especially in the context of law enforcement, underscores the need for improvement in the

1

4 D.L. Faigman, M.J. Saks, J. Sanders, and E.K. Cheng. 2007-2008. Modern Scientific Evidence: The Law and Science of Expert Testimony. Eagan, MN: Thomson/West, § 29.4, p.6. See also P.C. Giannelli and E.J. Imwinkelried. 2007. Scientific Evidence, 4th ed. Albany, NY: Lexis Publishing Co., on the latest forensic techniques and scientific concepts used in collecting and evaluating evidence.



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3 The Admission of Forensic Science Evidence in Litigation This chapter describes the legal system’s reliance on forensic science evidence in criminal prosecutions and examines the existing adversarial process for admitting this type of evidence. The report describes and ana- lyzes the current situation and makes recommendations for the future. No judgment is made about past convictions and no view is expressed as to whether courts should reassess cases that already have been tried. The report finds that the existing legal regime—including the rules governing the admissibility of forensic evidence, the applicable standards governing appellate review of trial court decisions, the limitations of the adversary process, and judges and lawyers who often lack the scientific expertise necessary to comprehend and evaluate forensic evidence—is inadequate to the task of curing the documented ills of the forensic science disciplines. This matters a great deal, because “forensic science is but the handmaiden of the legal system.”1 As explained in Chapters 4 and 5, there are serious issues regarding the capacity and quality of the current forensic science system; yet, the courts continue to rely on forensic evidence without fully understanding and addressing the limitations of different forensic science disciplines. This profound conjunction of law and science, especially in the context of law enforcement, underscores the need for improvement in the 1 4 D.L. Faigman, M.J. Saks, J. Sanders, and E.K. Cheng. 2007-2008. Modern Scientific Eidence: The Law and Science of Expert Testimony. Eagan, MN: Thomson/West, § 29.4, p.6. See also P.C. Giannelli and E.J. Imwinkelried. 2007. Scientific Eidence, 4th ed. Albany, NY: Lexis Publishing Co., on the latest forensic techniques and scientific concepts used in collecting and evaluating evidence. 

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 STRENGTHENING FORENSIC SCIENCE IN THE UNITED STATES forensic science community. The report concludes that every effort must be made to limit the risk of having the reliability of certain forensic science methodologies judicially certified before the techniques have been properly studied and their accuracy verified. LAW AND SCIENCE Science and law always have had an uneasy alliance: Since as far back as the fourteenth century, scientific evidence has posed profound challenges for the law. At bottom, many of these challenges arise from fundamental differences between the legal and scientific processes. . . . The legal system embraces the adversary process to achieve “truth,” for the ultimate purpose of attaining an authoritative, final, just, and so- cially acceptable resolution of disputes. Thus law is a normative pursuit that seeks to define how public and private relations should function. . . . In contrast to law’s vision of truth, however, science embraces empirical analysis to discover truth as found in verifiable facts. Science is thus a descriptive pursuit, which does not define how the universe should be but rather describes how it actually is. These differences between law and science have engendered both sys- temic and pragmatic dilemmas for the law and the actors within it. . . . Moreover, in almost every instance, scientific evidence tests the abilities of judges, lawyers, and jurors, all of whom may lack the scientific expertise to comprehend the evidence and evaluate it in an informed manner.2 Nowhere are these dilemmas more evident than in decisions pertaining to the admissibility of forensic science evidence proffered in criminal trials. Forensic science experts and evidence are routinely used in the service of the criminal justice system. DNA testing may be used to determine whether sperm found on a rape victim came from an accused party; a latent fingerprint found on a gun may be used to determine whether a defendant handled the weapon; drug analysis may be used to determine whether pills found in a person’s possession were illicit; and an autopsy may be used to determine the cause of death of a murder victim. In order for qualified forensic science experts to testify competently about forensic evidence, they must first find the evidence in a usable state and properly preserve it. A la- tent fingerprint that is badly smudged when found cannot be usefully saved, analyzed, or explained. An inadequate drug sample may be insufficient to allow for proper analysis. And, DNA tests performed on a contaminated 2 Developments in the law—confronting the new challenges of scientific evidence. 108 Harv. L. rev. 1481, 1484 (1995) (hereinafter “Developments in the law”) (footnotes omitted); see also M.A. Berger and L.M. Solan. The uneasy relationship between science and law: An essay and introduction. 73 Brook. L. rev. 847 (2008).

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 FORENSIC SCIENCE EVIDENCE IN LITIGATION or otherwise compromised sample cannot reliably identify or eliminate an individual as the perpetrator of a crime. These are important matters having to do with the proper “processing” of forensic evidence. The law’s greatest dilemma in its heavy reliance on forensic evidence, however, concerns the question of whether—and to what extent—there is science in any given “forensic science” discipline.3 The degree of science in a forensic science method may have an impor- tant bearing on the reliability of forensic evidence in criminal cases. There are two very important questions that should underlie the law’s admission of and reliance upon forensic evidence in criminal trials: (1) the extent to which a particular forensic discipline is founded on a reliable scientific methodology that gives it the capacity to accurately analyze evidence and report findings and (2) the extent to which practitioners in a particular forensic discipline rely on human interpretation that could be tainted by error, the threat of bias, or the absence of sound operational procedures and robust performance standards. These questions are significant:4 The goal of law enforcement actions is to identify those who have committed crimes and to prevent the criminal justice system from erroneously convicting the innocent. So it matters a great deal whether an expert is qualified to testify about forensic evidence and whether the evidence is sufficiently reliable to merit a fact finder’s reliance on the truth that it purports to support. As discussed in Chapters 4 and 5, no forensic method other than nuclear DNA analysis has been rigorously shown to have the capacity to consistently and with a high degree of certainty support conclusions about “individualization” (more commonly known as “matching” of an unknown item of evidence to a specific known source). In terms of scientific basis, the analytically based disciplines generally hold a notable edge over disciplines based on expert interpretation. But there also are important variations among the disciplines relying on expert interpretation. For example, there are more established protocols and available research for the analysis of fingerprints than for bite marks. In addition, there also are significant varia- tions within each discipline. Thus, not all fingerprint evidence is equally good, because the true value of the evidence is determined by the quality of the latent fingerprint image. In short, the interpretation of forensic evidence is not infallible. Quite the contrary. This reality is not always fully appre- 3 Principles of science are discussed in Chapter 4. 4 Descriptions and assessments of different forensic science disciplines are set forth in Chapters 5 and 6.

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 STRENGTHENING FORENSIC SCIENCE IN THE UNITED STATES ciated or accepted by many forensic science practitioners, judges, jurors, policymakers, or lawyers and their clients.5 THE FRYE STANDARD AND RuLE 702 OF THE FEDERAL RuLES OF EVIDENCE During the twentieth century, as science advanced, the legal system “attempted to develop coherent tests for the admissibility of scientific evi- dence.”6 The first notable development occurred in 1923 with the issuance of the landmark decision in Frye . United States.7 The Frye case involved a murder trial in which the defendant sought to demonstrate his innocence through the admission of a lie detector test that measured systolic blood pressure. The court rejected the evidence, stating: 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 force of the principle must be recog- nized, and while courts will go a long way in admitting expert testimony deduced from a well-recognized scientific principle or 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.8 The Frye decision held that the lie detector test was unreliable because it had not gained “general acceptance” in the relevant scientific community. The meaning of the Frye test is elusive. Indeed, “[t]he merits of the Frye test have been much debated, and scholarship on its proper scope and applica- tion is legion.”9 For many years, the Frye test was cited in both civil and criminal cases, but it was applied most frequently in criminal cases.10 “In the 70 years since its formulation in the Frye case, the ‘general acceptance’ 5 See 4 Faigman et al., op. cit., supra note 1, §29.3, p. 6 (“Few forensic scientists harbor serious misgivings about the expectation of good science on the part of their clients, be they the police, the prosecution, or the defense bar. . . . The clients want good science and the truth if it will help their case.”); S. Scarborough. 2005. They keep putting fingerprints in print. The CACNews. California Association of Criminalists, 2nd Quarter. Available at www.cacnews. org/news/2ndq05.pdf, p. 19 (“As scientists we are confident that any ‘critic’ that tries to prove the fallibility of fingerprints will actually find the opposite. Just as we testify to everyday.”). 6 Developments in the law, supra note 2, p. 1486. 7 Frye . United States, 54 App. D.C. 46, 293 F. 1013 (1923). 8 Ibid., p. 1014. 9 Daubert . Merrell Dow Pharm., Inc., 509 U.S. 579, 586 & n.4 (1993) (citing authorities). 10 P.C. Giannelli. 1993. “Junk science”: The criminal cases. Journal of Criminal Law and Criminology 84:105, 111, and n.35.

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 FORENSIC SCIENCE EVIDENCE IN LITIGATION test [was] the dominant standard for determining the admissibility of novel scientific evidence at trial.”11 In 1975, more than a half-century after Frye was decided, the Federal Rules of Evidence were promulgated to guide criminal and civil litigation in federal courts. The first version of Federal Rule of Evidence 702 provided that: 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 educa- tion, may testify thereto in the form of an opinion or otherwise.12 In place of Frye’s requirement of general scientific acceptance, mere “assis- tance” to the trier of fact appeared to be “the touchstone of admissibility under Rule 702.”13 After the promulgation of Rule 702, litigants, judges, and legal schol- ars remained at odds over whether the rule embraced the Frye standard or established a new standard.14 There was also much controversy sur- rounding the application of Rule 702 in civil cases. Most notably, Peter Huber popularized the now well-known phrase “junk science” to criticize the judiciary’s acceptance of unreliable expert testimony in support of tort claims.15 Huber’s study was sharply criticized,16 but it nonetheless spurred a debate over the use of expert testimony in the courts. However, “[d]espite the highly visible efforts to reform the rules governing experts in the civil arena, the ‘junk science’ debate . . . all but ignored criminal prosecutions.”17 The “neglect of the problems of expert testimony in criminal prosecutions” was seen by some as “deplorable.”18 11 Daubert, 509 U.S. at 585. 12 Fed. r. evid. 702, P.L. No. 93-595, § 1, 88 Stat. 1926 (effective January 2, 1975). 13 Giannelli, op. cit., supra note 10, p. 107. 14 T. Lyons. 1997. Frye, Daubert and where do we go from here? Rhode Island Bar Journal 45(5):21 (stating that “the vast majority of federal circuit and other courts adopted Frye as the standard of admissibility in their jurisdictions”). 15 P.W. Huber. 1991. Galileo’s Reenge: Junk Science in the Courtroom. New York: Basic Books. 16 See, e.g., K.J. Chesebro. Galileo’s retort: Peter Huber’s junk scholarship. 42 am. u. L. rev. 1637 (1993); Book Note: Rebel without a cause. 105 Harv. L. rev. 935 (1992). 17 Giannelli, op. cit., supra note 10, p. 110. 18 Ibid., pp. 110-111. Over time, a number of courts and commentators found the “general acceptance” test seriously wanting. See 1 Faigman et al., op. cit., supra note 1, § 1:6, pp. 13-17; P.C. Giannelli. The admissibility of novel scientific evidence: Frye . United States, a half-century later. 80 CoLum. L. rev. 1197, 1207-1208 (1980) (“[T]he problems Frye has engendered—the difficulties in applying the test and the anomolous results it creates—so far outweigh [its] advantages that the argument for adopting a different test has become over- whelming.”); M. McCormick. Scientific evidence: Defining a new approach to admissibility. 67 ioWa L. rev. 879, 915 (1982) (Frye’s “main drawbacks are its inflexibility, confusion of

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0 STRENGTHENING FORENSIC SCIENCE IN THE UNITED STATES THE DAUBERT DECISION AND THE SuPREME COuRT’S CONSTRuCTION OF RuLE 702 In 1993, in Daubert . Merrell Dow Pharmaceuticals, Inc., the Supreme Court finally clarified that Rule 702, not Frye, controlled the admission of expert testimony in the federal courts.19 Daubert was a civil case brought by two minor children and their parents, alleging that the children’s seri- ous birth defects had been caused by their mothers’ prenatal ingestion of Bendectin, a prescription drug marketed by the defendant pharmaceutical company. In support of a motion for summary judgment, the drug com- pany submitted an affidavit from a qualified expert, who stated that he had reviewed all the literature on Bendectin and human birth defects and had found no study showing Bendectin to be a human teratogen (i.e., an agent that can cause malformations of an embryo or fetus). The plaintiffs coun- tered with experts of their own, each of whom concluded that Bendectin could cause birth defects. Their conclusions were based on animal studies that found a link between Bendectin and malformations; pharmacologi- cal studies of the chemical structure of Bendectin that purported to show similarities between the structure of the drug and that of other substances known to cause birth defects; and the “reanalysis” of previously published epidemiological (human statistical) studies. The district court held that the expert testimony proffered by the plaintiffs was inadmissible, because their scientific evidence was not sufficiently established to have general accep- tance in the field to which it belonged.20 The court of appeals, citing Frye, affirmed the judgment of the district court, declaring that expert opinion based on a methodology that diverges significantly from the procedures accepted by recognized authorities in the field cannot be shown to be generally accepted as a reliable technique.21 The Supreme Court reversed, holding that the trial court had applied the wrong standard in assessing the expert testimony proffered by the plaintiffs. The case was then remanded for further proceedings. In construing and applying Rule 702, the Daubert Court ruled that a “trial judge must ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable.”22 The Court rejected the Frye test, noting that the drafting history of Rule 702 made no mention of Frye, issues, and superfluity.”); J.W. Strong. Questions affecting the admissibility of scientific evi- dence. u. iLL. L.F. 1, 14 (1970) (“The Frye standard, however, tends to obscure these proper considerations by asserting an undefinable general acceptance as the principal if not sole determinative factor.”). 19 509 U.S. 579 (1993). 20 Daubert . Merrell Dow Pharm, Inc., 727 F. Supp. 570, 575 (S.D. Cal. 1989). 21 Daubert . Merrell Dow Pharm., Inc., 951 F.2d 1128, 1129-30 (9th Cir. 1991). 22 Daubert, 509 U.S. at 589.

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 FORENSIC SCIENCE EVIDENCE IN LITIGATION “and a rigid ‘general acceptance’ requirement would be at odds with the ‘liberal thrust’ of the Federal Rules and their ‘general approach of relaxing the traditional barriers to ‘opinion’ testimony.’”23 The Court indicated that the subject of expert testimony should be “scientific knowledge,” so “evi- dentiary reliability will be based upon scientific validity.”24 The Court also emphasized that, in considering the admissibility of evidence, trial judges should focus “solely” on experts’ “principles and methodology,” and “not on the conclusions that they generate.”25 In sum, Daubert’s requirement that expert testimony pertain to “scientific knowledge” established a stan- dard of “evidentiary reliability.” In explaining this evidentiary standard, the Daubert Court pointed to several factors that might be considered by a trial judge: (1) whether a theory or technique can be (and has been) tested; (2) whether the theory or technique has been subjected to peer review and publication; (3) the known or potential rate of error of a particular scientific technique; (4) the existence and maintenance of standards controlling the technique’s opera- tion; and (5) a scientific technique’s degree of acceptance within a relevant scientific community.26 In the end, however, the Court emphasized that the inquiry under Rule 702 is “a flexible one.”27 The Court also rejected the suggestion that its liberal construction of Rule 702 would “result in a ‘free- for-all’ in which befuddled juries are confounded by absurd and irrational pseudoscientific assertions.”28 Rather, the Court expressed confidence in the adversary system, noting that “[v]igorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof are the traditional and appropriate means of attacking shaky but admissible evidence.”29 23 Ibid., p. 588 (internal citations omitted). 24 Ibid, p. 590 and n.9 (emphasis omitted). 25 Ibid., p. 595. In General Electric Co. . Joiner, 522 U.S. 136, 146 (1997), the Court added: “[C]onclusions and methodology are not entirely distinct from one another. Trained experts commonly extrapolate from existing data. But nothing in Daubert or the Federal Rules of Evidence requires a district court to admit opinion evidence that is connected to existing data only by the ipse dixit of the expert.” 26 Ibid., pp. 592-94. 27 Ibid., p. 594. In Kumho Tire Co., Ltd. . Carmichael, 526 U.S. 137 (1999), the Court confirmed that the Daubert factors do not constitute a definitive checklist or test. Kumho Tire importantly held that Rule 702 applies to both scientific and nonscientific expert testimony; the Court also indicated that the Daubert factors might be applicable in a trial judge’s as- sessment of the reliability of nonscientific expert testimony, depending upon “the particular circumstances of the particular case at issue.” 526 U.S. at 150. 28 Daubert, 509 U.S. at 595. 29 Ibid., p. 596.

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 STRENGTHENING FORENSIC SCIENCE IN THE UNITED STATES Daubert-type questions may be raised by the parties pretrial,30 or during the course of trial,31 or sua sponte by the trial judge.32 Sometimes a trial judge will conduct a formal “Daubert hearing” before ruling on a party’s objection to expert testimony; sometimes, however, the judge will simply entertain a party’s objection, hear arguments, and then rule.33 Judges sometimes rule on the briefs alone, without the benefit of formal argu- ments. There are any number of questions that might arise concerning the testimony of a forensic science expert or about the forensic evidence itself. These questions might include, inter alia, issues relating to one of the five Daubert factors or other factors appropriate to the forensic evidence, the relevance of the evidence, the qualifications of the expert, the adequacy of the evidentiary sample about which the expert will be testifying, and the procedures followed in the handling and processing of the evidence. After considering the matter at issue, a trial judge may exclude the evidence in whole or in part, prevent or limit the testimony of the expert witness, or deny the challenge. The Supreme Court has made it clear that trial judges have great discretion in deciding on the admissibility of evidence under Rule 702, and that appeals from Daubert rulings are subject to a very narrow abuse-of-discretion standard of review.34 Most importantly, in Kumho Tire Co., Ltd. . Carmichael, the Court made it clear that “whether Daubert’s specific factors are, or are not, reasonable measures of reliability in a par- ticular case is a matter that the law grants the trial judge broad latitude to determine.”35 THE 2000 AMENDMENT OF RuLE 702 In 2000, Rule 702 was amended “in response to Daubert.”36 The re- vised rule provides: 30 See, e.g., Alfred . Caterpillar, Inc., 262 F.3d 1083, 1087 (10th Cir. 2001). (“[B]ecause Daubert generally contemplates a ‘gatekeeping’ function, not a ‘gotcha’ junction, [the case law] permits a district court to reject as untimely Daubert motions raised late in the trial process.”) 31 See, e.g., United States . Alatorre, 222 F.3d 1098, 1100 (9th Cir. 2000) (holding trial courts are not compelled to conduct pretrial hearings in order to discharge the gatekeeping function under Daubert as to expert testimony). 32 See, e.g., Hoult . Hoult, 57 F.3d 1, 4 (1st Cir. 1995) (“We think Daubert does instruct district courts to conduct a preliminary assessment of the reliability of expert testimony, even in the absence of an objection.”). 33 1 Faigman et al., op. cit., supra note 1, § 1.8, p. 23 (stating “[i]n general, most courts considering the matter hold that a separate hearing to determine the validity of the basis for scientific evidence is not required” and discussing cases). 34 See Gen. Elec. Co. . Joiner, 522 U.S. 136, 142-43 (1997). 35 Kumho Tire Co., Ltd. . Carmichael, 526 U.S. 137, 153 (1999). 36 Fed. r. evid. 702 advisory committee’s note (2000 Amendments).

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 FORENSIC SCIENCE EVIDENCE IN LITIGATION 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 educa- tion, may testify thereto in the form of an opinion or otherwise, if (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case.37 The commentary accompanying the revised rule38 recites the “Daubert factors” and then goes on to explain that: Courts both before and after Daubert have found other factors relevant in determining whether expert testimony is sufficiently reliable to be con- sidered by the trier of fact. These factors include: (1) Whether experts are proposing to testify about matters growing natu- rally and directly out of research they have conducted independent of the litigation, or whether they have developed their opinions expressly for purposes of testifying. (2) Whether the expert has unjustifiably extrapolated from an accepted premise to an unfounded conclusion.39 (3) Whether the expert has adequately accounted for obvious alternative explanations. (4) Whether the expert is being as careful as he would be in his regular professional work outside his paid litigation consulting. (5) Whether the field of expertise claimed by the expert is known to reach reliable results for the type of opinion the expert would give.40 All of these factors remain relevant to the determination of the reliability of expert testimony under the rule as amended. The commentary accompanying the revised rule also notes that: 37 Fed. r. evid. 702. 38 Fed. r. evid. 702 advisory committee’s note (2000 Amendments) (citations and quota- tion marks omitted). 39 The commentary cites General Electric, 522 U.S. at 146 (noting that in some cases a trial court “may conclude that there is simply too great an analytical gap between the data and the opinion proffered”). 40 The commentary cites Kumho Tire, 526 U.S. at 150 (Daubert’s general acceptance fac- tor does not “help show that an expert’s testimony is reliable where the discipline itself lacks reliability, as for example, do theories grounded in any so-called generally accepted principles of astrology or necromancy.”); Moore . Ashland Chem., Inc., 151 F.3d 269 (5th Cir. 1998) (en banc) (clinical doctor was properly precluded from testifying to the toxicological cause of the plaintiff’s respiratory problem, where the opinion was not sufficiently grounded in scien- tific methodology); Sterling . Velsicol Chem. Corp., 855 F.2d 1188 (6th Cir. 1988) (rejecting testimony based on “clinical ecology” as unfounded and unreliable).

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 STRENGTHENING FORENSIC SCIENCE IN THE UNITED STATES [T]he amendment [to Rule 702] does not distinguish between scientific and other forms of expert testimony. The trial court’s gatekeeping function ap- plies to testimony by any expert. While the relevant factors for determining reliability will vary from expertise to expertise, the amendment rejects the premise that an expert’s testimony should be treated more permissively simply because it is outside the realm of science. An opinion from an expert who is not a scientist should receive the same degree of scrutiny for reliability as an opinion from an expert who purports to be a scientist. Some types of expert testimony will be more objectively verifiable, and subject to the expectations of falsifiability, peer review, and publication, than others. Some types of expert testimony will not rely on anything like a scientific method, and so will have to be evaluated by reference to other standard principles attendant to the particular area of expertise. The trial judge in all cases of proffered expert testimony must find that it is properly grounded, well-reasoned, and not speculative before it can be admitted. The expert’s testimony must be grounded in an accepted body of learning or experience in the expert’s field, and the expert must explain how the conclusion is so grounded. The amendment requires that the testimony must be the product of reliable principles and methods that are reliably applied to the facts of the case. While the terms “principles” and “methods” may convey a certain im- pression when applied to scientific knowledge, they remain relevant when applied to testimony based on technical or other specialized knowledge. For example, when a law enforcement agent testifies regarding the use of code words in a drug transaction, the principle used by the agent is that participants in such transactions regularly use code words to conceal the nature of their activities. The method used by the agent is the application of extensive experience to analyze the meaning of the conversations. So long as the principles and methods are reliable and applied reliably to the facts of the case, this type of testimony should be admitted. Nothing in this amendment is intended to suggest that experience alone— or experience in conjunction with other knowledge, skill, training or edu- cation—may not provide a sufficient foundation for expert testimony. To the contrary, the text of Rule 702 expressly contemplates that an expert may be qualified on the basis of experience. In certain fields, experience is the predominant, if not sole, basis for a great deal of reliable expert testimony. See, e.g., United States . Jones, 107 F.3d 1147 (6th Cir. 1997) (no abuse of discretion in admitting the testimony of a handwriting ex- aminer who had years of practical experience and extensive training, and who explained his methodology in detail). . . . See also Kumho Tire Co. . Carmichael, 119 S. Ct.1167, 1178 (1999) (stating that “no one denies that an expert might draw a conclusion from a set of observations based on extensive and specialized experience.”).41 41 Fed. r. evid. 702 advisory committee’s note (2000 Amendments).

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 FORENSIC SCIENCE EVIDENCE IN LITIGATION Given this view of Rule 702—which makes clear that “technical or other specialized knowledge” may be credited as expert testimony “so long as the principles and methods are reliable and applied reliably to the facts of the case”—it is not surprising that the courts might be hard pressed, under existing standards of admissibility, to hold some forensic science practitio- ners to the more demanding standards of the traditional sciences.42 AN OVERVIEW OF JuDICIAL DISPOSITIONS OF DAUBERT-TyPE QuESTIONS Assessing the admission of forensic evidence in litigation is no small undertaking, given the huge number of cases in which such evidence is proffered. Moreover, although Daubert remains the standard by which ad- missibility in federal cases is measured under Federal Rule of Evidence 702, states remain free to apply other evidentiary standards. Some states still ap- ply some version of the Frye standard, while others have adopted Daubert or some version of the Daubert test.43 Considering the patchwork of state standards and the fact that “[s]tate courts receive 200 times more criminal prosecutions than federal courts,” because “[f]orensic science is used most commonly in crimes of violence, and most crimes of violence are tried in state court,”44 a comprehensive overview would be difficult to create. The focus of this section and succeeding sections of this chapter will be on judicial dispositions of Daubert-type questions in criminal cases in the federal courts. The reason for this is that, although not every state has adopted the Daubert standard, there is little doubt that Daubert has ef- fectively set a norm that applies in every federal court and in a great many state jurisdictions. It cannot be ignored, and the reported federal cases give the best evidence of how Daubert is applied by the judiciary. Judicial dispositions of Daubert-type questions in criminal cases have been criticized by some lawyers and scholars who thought that the Supreme Court’s decision would be applied more rigorously to protect the rights of accused parties: [Daubert] obligated trial court judges to assume the role of “gatekeepers” and to exclude proffered scientific evidence unless it rested on scientifically valid reasoning and methodology. Many thought Daubert would be the 42 See generally Giannelli and Imwinkelried, op. cit., for thoughtful discussions of the admis- sibility of some forms of forensic science testimony as technical or other specialized knowledge under Rule 702. 43 See generally D.E. Bernstein and J.D. Jackson. The Daubert trilogy in the states. 44 JurimetriCs J. 351 (2004). 44 P.J. Neufeld. 2005. The (near) irrelevance of Daubert to criminal justice: And some sug- gestions for reform. American Journal of Public Health 95(Supp. 1):S107, S110.

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00 STRENGTHENING FORENSIC SCIENCE IN THE UNITED STATES ted by courts in the United States. When 2 profiles are found to “match” in a search of the Federal Bureau of Investigation’s (FBI’s) Combined DNA Index System (CODIS) database using 13 short tandem repeat (STR) loci, the likelihood that the profiles came from different people is extremely small. In other words, assuming the samples were properly collected and analyzed, an observer may state with a high degree of confidence that the two profiles likely came from the same person. Among existing forensic methods, only nuclear DNA analysis has been rigorously shown to have the capacity to consistently, and with a high de- gree of certainty, demonstrate a connection between an evidentiary sample and a specific individual or source. Indeed, DNA testing has been used to exonerate persons who were convicted as a result of the misapplication of other forensic science evidence.58 However, this does not mean that DNA evidence is always unassailable in the courtroom. There may be problems in a particular case with how the DNA was collected,59 examined in the laboratory,60 or interpreted, such as when there are mixed samples, limited amounts of DNA, or biases due to the statistical interpretation of data from partial profiles.61 Courts were able to subject DNA evidence to rigorous evaluation U.S. 1086 (2006); United States . Shea, 957 F. Supp. 331, 340-41 (D.N.H. 1997), aff’d, 159 F.3d 37 (1st Cir. 1998). 58 According to The Innocence Project, there have been 220 postconviction DNA exon- erations in the United States since 1989. See The Innocence Project, Fact Sheet: Facts on Post-Conviction DNA Exonerations. Available at www.innocenceproject.org/Content/351. php; see also B.L. Garrett. Judging innocence. 108 CoLum. L. rev. 55 (2008) (discussing the results of an empirical study of the types of faulty evidence that was admitted in more than 200 cases for which DNA testing subsequently enabled postconviction exonerations); but see J. Collins and J. Jarvis. 2008. The Wrongful Coniction of Forensic Science. Crime LaB re- Port. Available at www.crimelabreport.com/library/pdf/wrongful_conviction.pdf (contesting the percentage of exonerated defendants whose convictions allegedly were based on faulty forensic science). 59 See, e.g., W.C. Thompson. DNA evidence in the O.J. Simpson trial. 67 u. CoLo. L. rev. 827 (1996) (detailing the defense counsel’s theory that proper procedures were not followed in the collection or handling of the DNA samples at various points in the murder investigation). 60 See, e.g., L. Hart. 2003. “DNA Lab’s Woes Cast Doubt on 68 Prison Terms.” Los Angeles Times. March 31, at 19; A. Liptak. 2003. “Houston DNA Review Clears Convicted Rapist, and Ripples in Texas Could Be Vast.” New York Times. March 11, at A14; R. Tanner. 2003. “Crime Labs Stained by a Shadow of a Doubt.” Los Angeles Times. July 13, at 18. 61 See, e.g., Coy . Renico, 414 F. Supp. 2d 744, 761-63 (E.D. Mich. 2006) (rejecting habeas petitioner’s claim that he was denied a fair trial because the statistical techniques used to evalu - ate mixed DNA samples were insufficiently reliable); see also B.S. Weir. 2007. The rarity of DNA profiles. Annals of Applied Statistics 1(2):358-370 (suggesting that wholesale searches of large DNA databases for solving cold cases might yield false positives with some regularity).

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0 FORENSIC SCIENCE EVIDENCE IN LITIGATION standards from the beginning,62 because scientific groundwork for DNA analysis had been laid outside the context of law enforcement. The National Institutes of Health (NIH) and other respected institutions funded and conducted extensive basic research, followed by applied research. Serious studies on DNA analysis preceded the establishment and implementation of “individualization” criteria and parameters for assessing the probative value of claims of individualization. This history stands in sharp contrast to the history of research involving most other forensic science disciplines, which have not benefitted from extensive basic research, clinical applica- tions, federal oversight, vast financial support from the private sector for applied research, and national standards for quality assurance and quality control. The goal is not to hold other disciplines to DNA’s high standards in all respects; after all, it is unlikely that most other current forensic methods will ever produce evidence as discriminating as DNA. However, using Daubert as a guide, the least that the courts should insist upon from any forensic discipline is certainty that practitioners in the field adhere to enforceable standards, ensuring that any and all scientific testimony or evidence admitted is not only relevant, but reliable. Judicial Dispositions of Questions Relating to Drug Identification Over the years, there have been countless instances in which trial judges have assessed the admissibility of expert testimony relating to drug analy- ses, either sua sponte or pursuant to objections raised by defense counsel. Because trial court decisions in these matters often are resolved without published written opinions and with no challenges on appeal, there is no sure way to know how often trial judges deny the admissibility of the evi- dence. Trial judges may sometimes sustain challenges to the admissibility of expert testimony, especially in instances where the defense can show defects in the foundational laboratory reports.63 But there are very few such reported cases. In addition to alleged defects in laboratory reports and sampling pro- cedures, trial courts routinely consider whether experts possess the neces- sary qualifications to testify and, more generally, whether expert testimony is sufficiently reliable to be admitted under Daubert and Federal Rule of Evidence 702. However, in published opinions addressing expert testimony based on drug identification, federal appellate courts rarely reverse trial 62 See supra text accompanying note 54; see also Go’t of V.I. . Byers, 941 F. Supp. 513 (D.V.I. 1996); United States . Jakobetz, 747 F. Supp. 250 (D. Vt. 1990), aff’d, 955 F.2d 786 (2d Cir. 1992). 63 See, e.g., United States . Diaz, 2006 WL 3512032 (N.D. Cal. 2006).

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0 STRENGTHENING FORENSIC SCIENCE IN THE UNITED STATES court decisions rejecting Daubert challenges.64 Why? First, as noted above, in cases where the evidence is excluded at trial, no appeal will be taken. Second, the scientific methodology supporting many drug tests is sound. This means that, regardless of the standard of review, most decisions by trial courts will withstand scrutiny. Finally, courts of appeals owe great deference to trial court judgments on questions relating to the admission of evidence.65 The importance of the limited standard of review was clearly explained in United States . Brown:66 Immersed in the case as it unfolds, a district court is more familiar with the procedural and factual details and is in a better position to decide Daubert issues. The rules relating to Daubert issues are not precisely calibrated and must be applied in case-specific evidentiary circumstances that often defy generalization. And we don’t want to denigrate the importance of the trial and encourage appeals of rulings relating to the testimony of expert witnesses. All of this explains why the task of evaluating the reliability of expert testimony is uniquely entrusted to the district court under Daubert, and why we give the district court considerable leeway in the execution of its duty. That is true whether the district court admits or excludes ex- pert testimony. Joiner, 522 U.S. at 141-42 (“A court of appeals applying ‘abuse-of-discretion’ review to [Daubert] rulings may not categorically dis- tinguish between rulings allowing expert testimony and rulings disallowing it.”). And it is true where the Daubert issue is outcome determinative.67 Judicial Dispositions of Questions Relating to Fingerprint Analyses Over the years, the courts have admitted fingerprint evidence, even though this evidence has “made its way into the courtroom without empiri- cal validation of the underlying theory and/or its particular application.”68 The courts sometimes appear to assume that fingerprint evidence is irrefut- able. For example, in United States . Crisp, the court noted that “[w]hile the principles underlying fingerprint identification have not attained the 64 See, e.g., United States . Moreland, 437 F.3d 424, 430-31 (4th Cir. 2006), cert. denied, 547 U.S. 1142 (2006); United States . Scalia, 993 F.2d 984, 988-90 (1st Cir. 1993). 65 See, e.g., United States . Gaskin, 364 F.3d 438, 460 n.8 (2d Cir. 2004) (holding that “when a party questions whether sound scientific methodology provides a basis for an expert opinion, it may move to preclude the admission of the opinion” under Daubert; however, when a defendant makes no such motion and instead stipulates to the admissibility of the expert opinion, “he cannot complain on appeal that the opinion lacks foundation”). 66 415 F.3d 1266 (11th Cir. 2005). 67 Ibid., pp. 1265-66 (alteration in original) (internal quotation marks, other internal cita- tions omitted). 68 M.A. Berger. Procedural paradigms for applying the Daubert test. 78 minn. L. rev. 1345, 1354 (1994).

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0 FORENSIC SCIENCE EVIDENCE IN LITIGATION status of scientific law, they nonetheless bear the imprimatur of a strong general acceptance, not only in the expert community, but in the courts as well.”69 The court went on to say: [E]ven if we had a more concrete cause for concern as to the reliability of fingerprint identification, the Supreme Court emphasized in Daubert that “[v]igorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof are the traditional and appropri- ate means of attacking shaky but admissible evidence.” Daubert, 509 U.S. at 596. Ultimately, we conclude that while further research into fingerprint analysis would be welcome, “to postpone present in-court utilization of this bedrock forensic identifier pending such research would be to make the best the enemy of the good.”70 Opinions of this sort have drawn sharp criticism: [M]any fingerprint decisions of recent years . . . display a remarkable lack of understanding of certain basic principles of the scientific method. Court after court, for example, [has] repeated the statement that fingerprinting met the Daubert testing criterion by virtue of having been tested by the adversarial process over the last one-hundred years. This silly statement is a product of courts’ perception of the incomprehensibility of actually limit- ing or excluding fingerprint evidence. Such a prospect stilled their critical faculties. It also transformed their admissibility standard into a Daubert- permissive one, at least for that subcategory of expertise.71 This is a telling critique, especially when one compares the judicial decisions that have pursued rigorous scrutiny of DNA typing with the decisions that have applied less stringent standards of review in cases involving fingerprint evidence. In holding that fingerprint evidence satisfied Daubert’s reliability and relevancy standards for admissibility, the Fourth Circuit’s decision in Crisp noted approvingly that “the Seventh Circuit [in United States . Haard, 260 F.3d 597 (7th Cir. 2001)] determined that Daubert’s ‘known error rate’ factor was satisfied because the expert in Haard had testified that the error rate for fingerprint comparison was ‘essentially zero.’”72 This statement appears to overstate the expert’s testimony in Haard, and gives fuel to the misconception that the forensic discipline 69 324 F.3d 261, 268 (4th Cir. 2003). 70 Ibid., pp. 269-70 (second alteration in original) (other internal citation omitted). 71 1 Faigman et al., op. cit., supra note 1, § 1:1, p. 4; see also J.J. Koehler. Fingerprint er- ror rates and proficiency tests: What they are and why they matter. 59 Hastings L.J. 1077 (2008). 72 324 F.3d at 269 (quoting Haard, 260 F.3d at 599).

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0 STRENGTHENING FORENSIC SCIENCE IN THE UNITED STATES of fingerprinting is infallible. The Haard opinion actually described the expert’s testimony as follows: [The expert] testified that the error rate for fingerprint comparison is essentially zero. Though conceding that a small margin of error exists because of differences in individual examiners, he opined that this risk is minimized because print identifications are typically confirmed through peer review. [The expert] did acknowledge that fingerprint examiners have not adopted a single standard for determining when a fragmentary latent fingerprint is sufficient to permit a comparison, but he suggested that the unique nature of fingerprints is counterintuitive to the establishment of such a standard and that through experience each examiner develops a comfort level for deciding how much of a fragmentary print is necessary to permit a comparison.73 This description of the expert’s equivocal testimony calls into question any claim that fingerprint evidence is infallible. The decision in Crisp also pointed out that “[f]ingerprint identification has been admissible as reliable evidence in criminal trials in this country since at least 1911.”74 The court, however, pointed to no studies supporting the reliability of fingerprint evidence. When forensic DNA first appeared, it was sometimes called “DNA fingerprinting” to suggest that it was as reli- able as fingerprinting, which was then viewed as the premier identification science and one that consistently produced irrefutable results. During the effort to validate DNA evidence for courtroom use, however, it became apparent that assumptions about fingerprint evidence had been reached without the scientific scrutiny being accorded DNA. When the Supreme Court decided Daubert in 1993, with its emphasis on validation, legal com- mentators turned their attention to fingerprinting and began questioning whether experts could match and attribute fingerprints with a zero error rate as the FBI expert claimed in Haard, and whether experts should be allowed to testify and make these claims in the absence of confirmatory studies. As noted above, most of these challenges have thus far failed, but the questions persist. The 2004 Brandon Mayfield case refueled the debate over fingerprint evidence. The chronology of events in the Mayfield case is as follows: 73 Haard, 260 F.3d at 599. The Haard decision is sharply criticized by 1 Faigman et al., op. cit., supra note 1, § 1:30, pp. 86-89. 74 Crisp, 324 F.3d at 266. The decision cites a number of other legal references, includ- ing, inter alia: People . Jennings, 96 N.E. 1077 (1911); J.L. Mnookin. Fingerprint evidence in an age of DNA profiling. 67 Brook. L. rev. 13 (2001) (discussing history of fingerprint identification evidence).

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0 FORENSIC SCIENCE EVIDENCE IN LITIGATION March 11, 2004: Terrorists detonate bombs on a number of trains in Madrid, Spain, killing approximately 191 people, and injuring thousands more, including a number of United States citizens. May 6, 2004: Brandon Bieri Mayfield, a 37-year-old civil and immigration lawyer, practicing in Portland, Oregon, is arrested as a material witness with respect to a federal grand jury’s investigation into that bombing. An affidavit signed by FBI Special Agent Richard K. Werder, submitted in sup- port of the government’s application for the material witness arrest war- rant, [avers] that Mayfield’s fingerprint has been found on a bag in Spain containing detonation devices similar to those used in the bombings, and that he has to be detained so that he cannot flee before the grand jury has a chance to obtain his testimony. May 24, 2004: The government announces that the FBI has erred in its identification of Mayfield and moves to dismiss the material witness proceeding.75 In March 2006, the Office of the Inspector General of the U.S. Depart- ment of Justice issued a comprehensive analysis of how the misidentification occurred.76 And in November 2006, the federal government agreed to pay Mayfield $2 million for his wrongful jailing in connection with the 2004 terrorist bombings in Madrid.77 The Mayfield case and the resulting report from the Inspector General surely signal caution against simple, and unveri- fied, assumptions about the reliability of fingerprint evidence. In Maryland . Rose, a Maryland State trial court judge found that the Analysis, Comparison, Evaluation, and Verification (ACE-V) process (see Chapter 5) of latent print identification does not rest on a reliable factual foundation.78 The opinion went into considerable detail about the lack of error rates, lack of research, and potential for bias. The judge ruled that the State could not offer testimony that any latent fingerprint matched the prints of the defendant. The judge also noted that, because the case involved 75 S.T. Wax and C.J. Schatz. 2004. A multitude of errors: The Brandon Mayfield case. The Champion. September-October, p. 6. The facts of the case and Mayfield’s legal claims against the government are fully reported in Mayfield . United States, 504 F. Supp. 2d 1023 (D. Or. 2007). 76 Office of the Inspector General, Oversight and Review Division, U.S. Department of Jus- tice. 2006. A Reiew of the FBI’s Handling of the Brandon Mayfield Case. Available at www. usdoj.gov/oig/special/s0601/exec.pdf. 77 E. Lichtblau. 2006. “U.S. Will Pay $2 Million To Lawyer Wrongly Jailed.” New York Times. November 30, at A18. 78 Maryland . Rose, Case No. K06-0545, mem. op. at 31 (Balt. County Cir. Ct. Oct. 19, 2007) (holding that the ACE-V methodology of latent fingerprint identification was “a subjective, untested, unverifiable identification procedure that purports to be infallible” and therefore ruling that fingerprint evidence was inadmissible). The ACE-V process is described in Chapter 5.

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0 STRENGTHENING FORENSIC SCIENCE IN THE UNITED STATES the possibility of the death penalty, the reliability of the evidence offered against the defendant was critically important.79 The same concerns cited by the judge in Maryland . Rose can be raised with respect to other forensic techniques that lack scientific validation and careful reliability testing. Judicial Dispositions of Questions Relating to Other Forensic Disciplines Review of reported judicial opinions reveals that, at least in criminal cases, forensic science evidence is not routinely scrutinized pursuant to the standard of reliability enunciated in Daubert. The Supreme Court in Daubert indicated that the subject of an expert’s testimony should be “sci- entific knowledge”—which implies that such knowledge is based on sci- entific methods—to ensure that “evidentiary reliability will be based upon scientific validity.” The standard is admittedly “flexible,” but that does not render it meaningless. Any reasonable reading of Daubert strongly suggests that, when faced with forensic evidence, “trial judge[s] must ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable.” As the reported cases suggest, however, Daubert has done little to improve the use of forensic science evidence in criminal cases. For years in the forensic science community, the dominant argument against regulating experts was that every time a forensic scientist steps into a courtroom, his work is vigorously peer reviewed and scrutinized by opposing counsel. A forensic scientist might occasionally make an error in the crime laboratory, but the crucible of courtroom cross-examination 79 Professor Jennifer Mnookin has also highlighted an important concern over “the rhe- torical dimensions of the testimony . . . provide[d] in court” by members of the fingerprint community: At present, fingerprint examiners typically testify in the language of absolute certainty. Both the conceptual foundations and the professional norms of latent fingerprinting prohibit experts from testifying to identification unless they believe themselves certain that they have made a correct match. Experts therefore make only what they term “positive” or “absolute” identifica- tions—essentially making the claim that they have matched the latent print to the one and only person in the entire world whose fingertip could have produced it. In fact, if a fingerprint exam- iner testifies on her own initiative that a match is merely “likely” or “possible” or “credible,” rather than certain, she could possibly be subject to disciplinary sanction! Given the general lack of validity testing for fingerprinting; the relative dearth of difficult proficiency tests; the lack of a statistically valid model of fingerprinting; and the lack of validated standards for declaring a match, such claims of absolute, certain confidence in identification are unjustified, the product of hubris more than established knowledge. Therefore, in order to pass scrutiny under Daubert, fingerprint identification experts should exhibit a greater degree of epistemological humility. Claims of “absolute” and “positive” identification should be replaced by more modest claims about the meaning and significance of a “match.” J.L. Mnookin. 2008. The validity of latent fingerprint identification: Confessions of a finger- printing moderate. Law, Probability and Risk 7(2):127; see also Koehler, supra note 71.

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0 FORENSIC SCIENCE EVIDENCE IN LITIGATION would expose it at trial. This “crucible,” however, turned out to be utterly ineffective. ... Unlike the extremely well-litigated civil challenges, the criminal defendant’s challenge is usually perfunctory. Even when the most vulnerable forensic sciences—hair microscopy, bite marks, and handwriting—are attacked, the courts routinely affirm admissibility citing earlier decisions rather than facts established at a hearing. Defense lawyers generally fail to build a challenge with appropriate witnesses and new data. Thus, even if inclined to mount a Daubert challenge, they lack the requisite knowledge and skills, as well as the funds, to succeed.80 The reported decisions dealing with judicial dispositions of Daubert- type questions appear to confirm this assessment. As noted above, the courts often “affirm admissibility citing earlier decisions rather than facts established at a hearing.” Much forensic evidence—including, for example, bite marks81 and firearm and toolmark identifications82—is introduced in 80 Neufeld, supra note 44, at S109, S110. 81 There is nothing to indicate that courts review bite mark evidence pursuant to Daubert’s standard of reliability. See, e.g., Milone . Camp, 22 F.3d 693, 702 (7th Cir. 1994) (denying habeas petition after finding, in part, that the inclusion of bite mark testimony against the defendant had not denied him a fair trial, and stating that “while the science of forensic odon- tology might have been in its infancy at the time of trial . . . certainly there is some probative value to comparing an accused’s dentition to bite marks found on the victim.”). Two recent cases might, at first glance, seem to indicate that courts were beginning to seriously evaluate the general credibility of bite mark testimony, but this is not in fact the case. In Burke . Town of Walpole, 405 F.3d 66 (1st Cir. 2005), the court denied summary judgment to police officers in a 42 U.S.C. § 1983 action where exculpatory DNA evidence that directly contradicted inculpatory bite mark evidence was “intentionally or recklessly withheld from the officer who was actually preparing the warrant application,” ibid., p. 84, resulting in petitioner being wrongfully imprisoned for 41 days. However, the Burke court rejected the petitioner’s claim that the inclusion of bite mark evidence in the arrest warrant had demonstrated “reckless dis- regard for the truth,” because the method was generally unreliable. Ibid., pp. 82-83. In Ege . Yukins, 380 F. Supp. 2d 852 (E.D. Mich. 2005), aff’d in part and re’d in part, 485 F.3d 364 (6th Cir. 2007), the court granted the habeas petition of a defendant whose conviction was based in significant part on bite mark testimony from a later-discredited expert witness. But the disposition in Ege rested primarily on the flaws of one “particular witness and his particular testimony,” not on a judicial evaluation of “the [bite mark] field’s more general shortcomings.” 4 Faigman et al., op. cit., supra note 1, § 36:6, p. 662. 82 There is little to indicate that courts review firearms evidence pursuant to Daubert’s stan- dard of reliability. See e.g., United States . Hicks, 389 F.3d 514 (5th Cir. 2004) (upholding defendant’s conviction after finding, in part, that it was not an abuse of discretion for the court to admit testimony on shell casing comparisons by the Government’s firearms expert); United States . Foster, 300 F. Supp. 2d 375 (D. Md. 2004) (denying defendant’s motion to exclude expert firearms testimony). Several federal trial judges, however, have subjected expert firearm testimony to rigorous analysis under Daubert. In United States . Monteiro, 407 F. Supp. 2d 351 (D. Mass. 2006), Judge Saris concluded that toolmark identification testimony was

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0 STRENGTHENING FORENSIC SCIENCE IN THE UNITED STATES criminal trials without any meaningful scientific validation, determination of error rates, or reliability testing to explain the limits of the discipline. One recent judicial decision highlights the problem. In United States . Green, Judge Gertner acknowledged that toolmark identification testi- mony ought not be considered admissible under Daubert.83 But the judge pointed out that “the problem for the defense is that eery single court post-Daubert has admitted this testimony, sometimes without any search- ing review, much less a hearing.”84 Judge Gertner allowed the prosecution’s expert to describe the similarities between the shell casings at issue, but prohibited him from testifying that there was a definitive match. Obviously feeling bound by circuit precedent, the judge stated: I reluctantly [admit the evidence] because of my confidence that any other decision will be rejected by appellate courts, in light of precedents across the country, regardless of the findings I have made. While I recognize that the Daubert-Kumho standard does not require the illusory perfec- tion of a television show (CSI, this wasn’t), when liberty hangs in the balance—and, in the case of the defendants facing the death penalty, life itself—the standards should be higher than were met in this case, and than have been imposed across the country. The more courts admit this type of toolmark evidence without requiring documentation, proficiency testing, or evidence of reliability, the more sloppy practices will endure; we should require more.85 “[T]he undeniable reality is that the community of forensic science generally admissible under Daubert, but excluded the specific testimony at issue, because the experts failed to properly document their basis for identification, and because an independent examiner had not verified the experts’ conclusions. Likewise, in United States . Diaz, No. 05-CR-167, 2007 WL 485967, at *14 (N.D. Cal. Feb. 12, 2007), Judge Alsup allowed firearm identification testimony under Daubert, but prevented experts from testifying to their conclu- sions “to the exclusion of all other firearms in the world” and only allowed testimony “to a reasonable degree of certainty.” Cf. United States . Glynn, 578 F. Supp. 2d 569 (S.D.N.Y. 2008), where Judge Rakoff precluded testimony that a bullet and shell casings came from a firearm linked to the defendant “to a reasonable degree of ballistics certainty,” because “whatever else ballistics identification analysis could be called, it could not fairly be called ‘science.’” However, the judge ruled that although inadmissible under Daubert, testimony that the evidence was “more likely than not” from the firearm was admissible under Federal Rule of Evidence 401. See also Green, 405 F. Supp. 2d 104, discussed in the text. 83 405 F. Supp. 2d at 107-08. 84 Ibid., p. 108. 85 Ibid., p. 109 (footnotes omitted). “The case law on the admissibility of toolmark iden- tification and firearms identification expert evidence is typified by decisions admitting such testimony with little, and usually no, reference to legal authority beyond broad ‘discretion’ and an adroit sidestepping of any judicial duty to assure that experts’ claims are valid. Appellate courts defer to trial courts, and trial courts defer to juries. Later appellate courts simply defer to earlier appellate courts.” 4 Faigman et al., op. cit., supra note 1, § 34:5, p. 589.

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0 FORENSIC SCIENCE EVIDENCE IN LITIGATION professionals has not done nearly as much as it reasonably could have done to establish either the validity of its approach or the accuracy of its practitioners’ conclusions,”86 and the courts have been “utterly ineffective” in addressing this problem.87 CONCLuSION Prophetically, the Daubert decision observed that “there are important differences between the quest for truth in the courtroom and the quest for truth in the laboratory. Scientific conclusions are subject to perpetual revi- sion. Law, on the other hand, must resolve disputes finally and quickly.”88 But because accused parties in criminal cases are convicted on the basis of testimony from forensic science experts, much depends upon whether the evidence offered is reliable. Furthermore, in addition to protecting innocent persons from being convicted of crimes that they did not commit, we are also seeking to protect society from persons who have committed criminal acts. Law enforcement officials and the members of society they serve need to be assured that forensic techniques are reliable. Therefore, we must limit the risk of having the reliability of certain forensic science methodologies condoned by the courts before the techniques have been properly studied and their accuracy verified. “[T]here is no evident reason why [‘rigorous, systematic’] research would be infeasible.”89 However, some courts appear to be loath to insist on such research as a condition of admitting forensic science evidence in criminal cases, perhaps because to do so would likely “demand more by way of validation than the disciplines can presently offer.”90 Some legal scholars think that, “[o]ver time, if Daubert does not come 86Mnookin, op. cit., supra note 79. 87Neufeld, op. cit., supra note 44, p. S109. In Green, 405 F. Supp. 2d at 109 n.6, Judge Gertner also noted that: [R]ecent reexaminations of relatively established forensic testimony have produced striking results. Saks and Koehler, for example, report that forensic testing errors were responsible for wrongful convictions in 63% of the 86 DNA Exoneration cases reported by the Innocence Proj- ect at Cardozo Law School. Michael Saks and Jonathan Koehler, The Coming Paradigm Shift in Forensic Identification Science, 309 Science 892 (2005). This only reinforces the importance of careful analysis of expert testimony in this case. See also S.R. Gross, Conicting the Innocent (U. Mich. Law Sch. Pub. Law & Legal Theory Working Paper Series, Working Paper No. 103, 2008). Available at http://papers.ssrn.com/ sol3/papers.cfm?abstract_id=1100011 (forthcoming in Annual Reiew of Law & Social Sci- ence 2008). 88 Daubert . Merrell Dow Pharm., Inc., 509 U.S. 579, 596-97 (1993). 89 J. Griffin and D.J. LaMagna. 2002. Daubert challenges to forensic evidence: Ballistics next on the firing line. The Champion. September-October:21. 90 Ibid. See, e.g., Crisp, 324 F.3d at 270.

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0 STRENGTHENING FORENSIC SCIENCE IN THE UNITED STATES to be diluted or distorted, . . . courts will increasingly appreciate its power and flexibility to evaluate proffered expert testimony.”91 However, at least with respect to criminal cases, this may reflect an unrealistic assessment of the problem. “The principal difficulty, it appears, is that many [forensic science] techniques have been relied on for so long that courts might be re- luctant to rethink their role in the trial process. . . . In many forensic areas, effectively no research exists to support the practice.”92 As the discussion in this chapter indicates, the adversarial process re- lating to the admission and exclusion of scientific evidence is not suited to the task of finding “scientific truth.” The judicial system is encumbered by, among other things, judges and lawyers who generally lack the scientific expertise necessary to comprehend and evaluate forensic evidence in an informed manner, trial judges (sitting alone) who must decide evidentiary issues without the benefit of judicial colleagues and often with little time for extensive research and reflection, and the highly deferential nature of the appellate review afforded trial courts’ Daubert rulings. Furthermore, the judicial system embodies a case-by-case adjudicatory approach that is not well suited to address the systematic problems in many of the various forensic science disciplines. Given these realities, there is a tremendous need for the forensic science community to improve. Judicial review, by itself, will not cure the infirmities of the forensic science community.93 The development of scientific research, training, technology, and databases asso- ciated with DNA analysis have resulted from substantial and steady federal support for both academic research and programs employing techniques for DNA analysis. Similar support must be given to all credible forensic science disciplines if they are to achieve the degrees of reliability needed to serve the goals of justice. With more and better educational programs, accredited laboratories, certified forensic practitioners, sound operational principles and procedures, and serious research to establish the limits and measures of performance in each discipline, forensic science experts will be better able to analyze evidence and coherently report their findings in the courts. The present situation, however, is seriously wanting, both because of the limitations of the judicial system and because of the many problems faced by the forensic science community. 91 1 Faigman et al., op. cit., supra note 1, § 1:1, p. 5 n. 9. 92 Ibid. § 1:30, p. 85 (footnotes omitted). 93 See J.L. Mnookin. Expert evidence, partisanship, and epistemic competence. 73 Brook. L. rev. 1009, 1033 (2008) (“[S]o long as we have our adversarial system in much its pres- ent form, we are inevitably going to be stuck with approaches to expert evidence that are imperfect, conceptually unsatisfying, and awkward. It may well be that the real lesson is this: those who believe that we might ever fully resolve—rather than imperfectly manage—the deep structural tensions surrounding both partisanship and epistemic competence that per- meate the use of scientific evidence within our legal system are almost certainly destined for disappointment.”).