Monday, May 21, 2018

Firearms Toolmark Testimony: Looking Back and Forward

By inspecting toolmarks on bullets or spent cartridge cases, firearms examiners can supply valuable information on whether a particular gun fired the ammunition in question. But the limits on this information have not always been respected in court, and a growing number of opinions have tried to address this fact. A forthcoming article in a festschrift for Professor Paul Giannelli surveys the developing law on this type of feature-matching evidence.

The article explains how the courts have moved from a position of skepticism of the ability of examiners to link bullets and other ammunition components to a particular gun to full-blown acceptance of identification “to the exclusion of all other firearms.” From that apogee, challenges to firearm-mark evidence over the past decade or so, have generated occasional restrictions on the degree of confidence that firearms experts can express in court, but they have not altered the paradigm of making source attributions and exclusions instead of statements about the degree to which the evidence supports these conclusions. After reviewing the stages in the judicial reception of firearm-mark evidence, including the reactions to reports from the National Academy of Sciences and the President's Council of Advisors on Science and Technology, the article concludes by describing a more scientific, quantitative, evidence-based form of testimony that should supplant or augment the current experience-based decisions of skilled witnesses. A few excerpts follow:
From: David H. Kaye, Firearm-Mark Evidence: Looking Back and Looking Ahead, Case Western Reserve Law Review (forthcoming Vol. 68, Issue 3, 2018) (most footnotes omitted)

* * *
I. Rejection of Expert Source Attributions
For a time, courts did not admit testimony that items originated from a particular firearm. Some courts reasoned that jurors could make the comparisons and draw their own conclusions. In People v. Weber, for example, the trial court struck from the record an examiner’s testimony “that in his opinion the two bullets taken from the bodies were fired from this pistol, leaving that as a question for the jury to determine by an inspection of the bullets themselves.” In this 1904 trial, the court did not question the expert’s ability to discover toolmarks that could be probative of identity, but it saw no reason to believe that the expert would be better than lay jurors at drawing inferences from that information. Other courts allowed such opinions, but not if they were stated as “facts.” * * *

IV. Heightened Scrutiny Following the 2009 NAS Report
* * *
Neither the 2008 nor the 2009 NAS report made recommendations on admissibility of evidence, for that was not part of their charge. Practitioners and prosecutors proposed that this meant that the reports should or could not be taken as undermining the admissibility of traditional highly judgmental pattern-matching identifications. However, the committees’ reviews of the literature clearly lent credence to the questions about the routine admission of categorical source attributions based on firearm-marks. 50/ In five prominent published opinions, courts cited the NAS reports and the opinions cited in Part III of this Article to limit such testimony. * * *

50. For example, in describing the scientific basis of “forensic science fields like firearms examination,” the 2008 report quoted with approval an article by two forensic scientists stating that “[f]orensic individualization sciences that lack actual data, which is most of them, . . . simply . . . assume the conclusion of a miniscule probability of a coincidental match . . . .” [Nat'l Research Council Comm. To Assess the Feasibility, Accuracy, and Tech. Capability of a Nat'l Ballistics Database, Ballistic Imaging 1, 54-55 (Daniel L. Cork et al., eds. 2008)] (quoting John I. Thornton & Joseph L. Peterson, The General Assumptions and Rationale of Forensic Identification, in 3 David L. Faigman, David H. Kaye, Michael J. Saks, & Joseph Sanders, Modern Scientific Evidence: the Law and Science of Expert Testimony § 24-7.2, at 169 (2002)). Apparently recognizing the threat of such assessments, AFTE complained that the committees’ literature reviews were shallow. In response to the 2008 Report, it wrote that “the committee lacked the expertise and information necessary for the in-depth study that would be required to offer substantive statements with regard to these fundamental issues of firearm and toolmark identification.” [AFTE Comm. for the Advancement of the Sci. of Firearm & Toolmark Identification, The Response of the Association of Firearm and Tool Mark Examiners to the National Academy of Sciences 2008 Report Assessing the Feasibility, Accuracy, and Technical Capability of a National Ballistics Database, AFTE J., Summer 2008, at 243, available at https://afte.org/uploads/documents/position-nas-2008.pdf 243]. Likewise, it wrote that “the [2009] NAS committee in effect chose to ignore extensive research supporting the scientific underpinnings of the identification of firearm and toolmark evidence.” AFTE Comm. for the Advancement of the Sci. of Firearm & Toolmark Identification, The Response of the Association of Firearms and Tool Mark Examiners to the February 2009 National Academy of Science Report “Strengthening Forensic Science in the United States: A Path Forward,” AFTE J., Summer 2009, at 204, 206. According to AFTE, “years of empirical research . . . conclusively show[] that sufficient individuality is often present on tool (firearm tools or non-firearm tools) working surfaces to permit a trained examiner to conclude that a toolmark was made by a certain tool and that there is no credible possibility that it was made by any other tool working surface.” AFTE Comm. Response, supra * * * , at 242. After all, “[t]he principles and techniques utilized in forensic firearms identification have been used internationally for nearly a century by the relevant forensic science community to both identify and exclude specific firearms as the source of fired bullets and cartridge cases.” Id. at 237 (emphasis added). Prosecutors too sought to blunt the implications of the skeptical statements about the limited validation of the premises of the traditional theory of firearm-mark identification with an affidavit from the chairman of the NAS committee that wrote the 2008 Report. Affidavit of John E. Rolph at 1-3, United States v. Edwards, No. F-516-01 (D.C. Super. Ct., May 23, 2008). Yet, the affidavit merely collects excerpts from the report itself and ends with one that could be read as supporting admissibility under certain conditions. For another affidavit from a committee member contending that NAS “has questioned the validity of these fundamental assumptions of uniqueness and reproducibility,” see Declaration of Alicia Carriquiry, PhD. In Support of Motion in Limine to Exclude Firearms Examiner’s Opinion at 5, People v. Knight, No. LA067366 (Cal. Super. Ct. Apr. 2012). The use of affidavits of one or two committee members to give their personal views on what the words that the committee as a whole agreed upon is ill-advised. It resembles asking individual members of Congress to provide their post hoc thoughts on what a committee report on legislation, or the statute itself, really meant.
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