Justice delayed is justice denied: wrongful convictions, eyewitness-expert testimony, and recent developments.

Author:Balko, Douglas

"[I]t is better that ten guilty persons escape, than that one innocent suffer." (1)


    Legal literature, periodicals, and judicial decisions have spilled much ink on the propriety and scope of the admissibility of expert opinion testimony on the reliability of eyewitness identifications. (2) In the interim, the scientific community continues to stockpile evidence that consistently concludes that eyewitness identifications are unreliable. (3) Many researchers contend that the most effective countermeasure to unreliable eyewitness testimony is the admission of expert testimony. (4) Nevertheless, courts across the country continue to preclude the admission of expert testimony regarding the accuracy of eyewitness accounts. (5)

    Unfortunately, more and more wrongful convictions stemming from eyewitness misidentifications continue to come to light. (6) If Sir William Blackstone's words resonate, and if scientifically dubious eyewitness identifications continue to lead to wrongful convictions, then it seems there should be firm guidelines regarding their admissibility, but that is generally not the case. (7) In most jurisdictions, the admission of expert testimony is left to the discretion of the trial judge. (8)

    Although courts have moved slowly in developing admissibility guidelines, society has increasingly strengthened its resolve to stop wrongful convictions. (9) For example, some state governments have taken an institutional approach by creating innocence commissions. (10) Additionally, there have been efforts in many states to amend the rules of professional conduct governing attorneys. (11) Finally, a myriad of public interest and policy groups have formed in recent years to address the problem of wrongful convictions. (12)

    This Note traces the history of the admissibility of eyewitness-expert testimony in the United States. (13) It then discusses the problematic nature of eyewitness evidence, canvassing some of the scientific evidence that undermines its reliability. (14) Next, it examines the measures taken to address wrongful convictions, including the establishment of innocence commissions and exceptions to client confidentiality rules in legal ethics. (15) Finally, this Note argues that these measures are ineffective and, given the societal interest in avoiding wrongful convictions and the role of eyewitness identifications in causing them, courts should take the lead in curbing wrongful convictions by liberally admitting eyewitness-expert testimony under Federal Rule of Evidence 702 (Rule 702). (16)


    1. Expert Testimony Proffers

      1. Early Admissibility Standards

        Proffers of expert testimony at trial were subject to the admissions criteria of Frye v. United States (17) for decades. (18) The Frye regime permits the admission of expert testimony at trial if the proponent can establish that the subject matter of the expert testimony is outside the range of the jury's common experience and knowledge and, more importantly, the scientific findings are sufficiently established to have gained general acceptance in the relevant scientific field. (19) The law of evidence underwent a substantial change in 1993 with the enactment of the Federal Rules of Evidence, and the Supreme Court was called upon to decide whether this change abrogated the Frye regime in Daubert v. Merrell Dow Pharmaceuticals, Inc. (20)

        The Daubert Court evaluated the language of Federal Rules of Evidence 401, 402 (Rule 402), and, most importantly, Rule 702, and compared them to the Frye standard. (21) The Court concluded that because "general acceptance" is not a necessary element in any of the Federal Rules, the Frye standard no longer controls in federal courts. (22) Instead, Daubert requires federal judges faced with a proffer of scientific expert testimony to make a preliminary assessment of whether the reasoning or methodology underlying the expert's testimony is scientifically valid by considering several nonexclusive features: its subjection to peer review; its known or potential error rate; its falsifiability, refutability, or testability; the existence and maintenance of standards controlling its operation; and its general acceptance in the relevant scientific community. (23)

        In response to Daubert and its progeny, Congress amended Rule 702. (24) A prominent case applying Daubert and, consequently, fostering amendment to Rule 702, is the Supreme Court case of Kumho Tire Co. v. Carmichael. (25) In Kumho, the Court extended the principles of Daubert to all expert testimony--not just scientific testimony. (26) The current version of Rule 702 is now structured to reflect the principles of Daubert. (27)

      2. Expert Testimony on the Reliability of Eyewitness Identifications

        In cases where testimony of an eyewitness is offered into evidence, litigants utilize eyewitness experts to opine on the reliability of the eyewitness testimony. (28) Eyewitness experts tend to be psychologists who testify about a variety of psychological processes and accuracy-related variables impacting eyewitness memory and testimony. (29) In criminal prosecutions, the defendant is most frequently the party seeking to admit eyewitness-expert testimony. (30)

        Advocates of eyewitness-expert testimony provide two general justifications for its admissibility. (31) First, voluminous research shows that juries are too receptive to, and over-reliant on, eyewitness evidence. (32) Because of this "overbelief" tendency, advocates argue that expert testimony is necessary to "challenge successfully the jurors' misplaced confidence in eyewitness testimony." (33) Second, regardless of a jury's overreliance on eyewitness testimony, expert testimony is necessary to educate the jury on how to discriminate between accurate and inaccurate witness testimony. (34) The science underlying these two justifications will be explained in Part II.B of this Note. (35)

        Eyewitness-expert testimony was excluded outright in the majority of American courts until recently. (36) This was true notwithstanding the fact that courts were aware of the problems eyewitness testimony poses. (37) Courts justified rejecting proffers of eyewitness experts on a number of grounds, including the ability of the adversarial process to unearth eyewitness defects and the use of jury instructions. (38) Some courts continue to exclude such testimony. (39)

        In 1973, the Ninth Circuit became the first court to establish guidelines for the admissibility of eyewitness-expert testimony. (40) Under the standard set forth in United States v. Amaral, parties offering eyewitness-expert testimony must satisfy four criteria. (41) First, the expert must be qualified. (42) Second, the subject matter must be proper. (43) Third, the expert testimony must conform to a generally accepted explanatory theory. (44) Finally, the probative value of the testimony must outweigh its prejudicial effect. (45)

        Today, the majority of courts permit eyewitness experts to testify, though the circumstances under which such testimony is admitted are "narrow." (46) United States v. Downing is the leading case for this proposition. (47) The Downing court was the first federal court to reverse as error a district court's exclusion of eyewitness-expert testimony. (48) The court recognized that eyewitness-expert testimony meets Rule 702's "helpfulness requirement" and rejected the notion that such testimony was within the common knowledge of the jury. (49) Downing was not, however, a complete victory for advocates of eyewitness-expert testimony because the court did limit the testimony's admissibility in some ways. (50)

        Courts continue to exclude eyewitness-expert testimony on various grounds. (51) For instance, judges frequently exclude expert testimony because they feel it invades the province of the jury. (52) Many judges feel the testimonial matter is within the common knowledge of jurors, and expert testimony on such a subject is unnecessary. (53) Judges also remain free to reject a proffer if they believe the prejudicial effect will outweigh the testimony's probative value. (54) Ultimately, it is within trial judges' discretion whether or not an expert witness's testimony may be admitted. (55)

    2. Eyewitness Reliability: A Survey of the Science

      After conducting extensive studies, scientists have almost unanimously concluded that eyewitness testimony is unreliable. (56) Contrary to what many people believe, the human mind does not simply capture memories upon experiencing an event. (57) Rather, memory is a much more complicated, tiered process: First, people witness an event (the acquisition stage), then they attempt to remember the event (the retention stage), and finally they recall the stored information (the retrieval stage). (58) Experts argue that at any point in this process, a number of factors can affect the accuracy, integrity, and completeness of an eyewitness account. (59) Experts categorize these factors into two types: estimator variables, which are factors inherent in the event itself, or system variables, which are factors that present themselves in the post-event legal proceedings. (60)

      There are a variety of well-established and thoroughly examined factors--both estimator and systematic--that influence witness accuracy. (61) A thorough treatment of every factor is beyond the scope of this Note, but this Part will briefly discuss some of the psychological factors that are most beyond the ken of the jury and, thus, lend themselves to an assessment by eyewitness experts. (62)

      1. Cross-Racial Identification

        A cross-racial identification entails a situation in which the observer and subject are of a different race. (63) Research shows that cross-racial identifications are notoriously unreliable. (64) Research also suggests that problems with cross-racial identification stem from the inability of members of one race to "encode" in their memory pertinent facial features of those from another race. (65) There is some...

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