The admissibility of forensic evidence in the courtroom has been a long-standing source of contention among scientists, attorneys, and scholars. Forensic science is science “used for the purposes of the law,” and forensic scientists are those tasked with examining evidence to form conclusions that assist investigators in understanding what occurred during the commission of a crime. A large subset of forensic science is “feature-comparison,” which entails analyzing footwear impressions, hair and fibers, latent fingerprints, toolmarks, and DNA evidence. The ultimate goal of forensic examiners in these disciplines is to “determine whether an evidentiary sample . . . is or is not associated with a potential source sample . . . based on the presence of similar patterns, impressions, features, or characteristics in the sample and the source.” Common scenarios include identifying a specific firearm as having fired certain ammunition or naming a specific person as the source of a fingerprint or DNA material.
Although they frequently seem the same, a forensic analyst’s goal should not be to assist in convicting a specific suspect but rather to enhance understanding of a crime, enabling attorneys to seek justice for it. This goal is derived from the ethical and scientific obligation imposed on forensic scientists to make findings supported by objective, unbiased analysis. When analysts deviate from a standard of objectivity, their credibility as an expert witness is easily challenged. Thus, the empirical validity and replicability of the analysis involved in different forensic disciplines has caused each to face varying degrees of scrutiny. For instance, DNA analysis is considered the “gold standard” of forensic science and faces few courtroom admissibility issues because of its reliable and objective methodology. In contrast, bitemark evidence, while once accepted, is now considered unreliable and scientifically invalid since its analysis requires a large degree of subjectivity.
Firearm identification, one of the most longstanding and well-established (albeit controversial) branches of forensic science, has faced increasingly vehement challenges to its admissibility in court over the past two decades. Following strong critiques in official reviews of the discipline in 2009 and 2016, legal scholars have routinely called for judges to renounce the current almost-guaranteed admissibility of firearm evidence in courtrooms. Yet, it has only been within the last few years that courts have begun to heed this advice and reconsider the evidence’s validity and reliability under the Daubert standard.
This trend culminated in the Maryland Supreme Court’s 2023 decision in Abruquah v. State, where it applied the Daubert-Rochkind factors to firearm evidence. It held that the reliability of the methodology underlying “identification” conclusions that a specific firearm fired “unknown” bullets was not scientifically supported. The holding created the first state-wide ban on firearm identification testimony relating to bullets. This seemingly new scrutiny and more rigid application of Daubert to firearm evidence casts doubt on the future admissibility of feature-comparison evidence.
