Summary of Murdock et. al
Introduction
Firearm and toolmark identification analysis has been heavily criticised in recent years; the major concern within this field of study is that there is no known error rate with these analyses. To supply an accurate error rate is problematic because of the “spectrum of variability in data”. There has been a continual effort made by the statistical community in order to estimate the random match probabilities (RMPs) and error rates of proper identification, however, there is a question of relevance with these RMPs. Some critics argue that there is no well established statistical basis of toolmark and firearm identification, but according to Murdock, their argument is not factual and lacks logic. There have been statistical models implemented to firearm and toolmark identification, but these models are limited and their relevancy has not yet been determined. Forensic science, however, is not the only science that lacks an exact structured model; for example, a meteorologist has no absolute guarantee of predicting the weather.
Review of the Current Literature in Statistical Applications for Firearms and Toolmarks
Since the early 20th century, numerous studies have been conducted to develop and test the statistical probabilities of finding a match with firearm and toolmark identification. With the new technological advances, examiners are now able to scan cartridges, bullets, and toolmarks in 3D. These advancements decrease the potential human error in analysing these pieces of evidence. Since these technologies, several studies have been done involving breech face markings on cartridge cases, striation marks, and to primer shear marks on cartridge cases. These new tools have been extremely beneficial to the forensic science community.
Current State of the Use of RMPs in Firearm and Toolmark Identification
Within firearm and toolmark identification, RMPs (random match probabilities) are hard to formulate. It is uncertain whether or not it is even reasonable to apply a RMP to the identification of firearms and toolmarks because of “the tool working surfaces, many of which are microscopically unique… may not remain stable over time”. Because of this and other factors, it will be challenging to produce a statistical model that can correctly identify the random toolmarks left by some tools.
Absolute Versus Practical Identification and Subjectivity
The main idea of this section was relevant evidence. In most cases, firearm and toolmark examiners are allowed to use the term “absolute doubt” to describe a piece of evidence, however, “reasonable certainty” is almost considered taboo in criminal cases. The writers later identify that the main flaw with these analyses of firearms and toolmark identification is subjectivity; expert opinions might differ across the board simply because of the methodology used, the amount of time a piece of evidence is analyzed, etc. This aspect has made an appearance in the courtroom when making final decisions in criminal cases. The authors also discuss how subjectivity is as an aspect of everyday life and its use within our personal lives as well as a part of the justice system.
Title & Abstract Discussion
The abstract of this paper primarily discusses “the current criticism leveled at firearm and toolmark analysis”. According to Murdock, the amount of critique aimed at these analyses is “misinformed and, at worst, punditry”; he then goes on to say that “the purpose(s) of this paper are to point out the logical fallacies in the arguments of a small group of pundits… and to give a balanced review of the literature regarding RMP models and statistical applications that have been carried out in forensic firearm and toolmark analysis.” What actually resulted from this paper is far different than the abstract’s original purpose. Murdock antagonized the work and opinions of most people who are aiming to improve the analysis of firearms and toolmarks. Murdock quotes “strong scrutiny is a healthy and necessary part of any scientific endeavor”, however he doesn’t seem to find value in the progress CSAFE and other research programs are doing for forensic science. “Schwartz and Carriquiry ignore the inescapable fact that firearm and toolmark identification works…” Both of the quotes are on the exact same page. It is ironic how he talks about the importance of scrutiny with the sciences, yet turns around and bashes those who try to improve on the methods and accuracy of firearm and toolmark identification. I expected his paper to indicate the discrepancies amongst experts’ opinions and the studies done in the past; however, I believe this paper simply was an attempt to burn the people who had different opinions than his own. His title alone was completely misleading; instead, he should have titled it “The Burning of People and their ‘Expert’ (said sarcastically) Opinions on Firearm and Toolmark Identification”. In essence, Murdock’s paper would have been an excellent example for Bryan to discuss with us on what we shouldn’t put on a poster and on a future paper.