Firearms and Ballistics

Chapter 7 of the book entitled 'Practical Veterinary Forensics' aims to introduce forensic veterinarians to the scientific concepts underpinning the field of firearms and ballistics. This introduction will enable practitioners to understand wound formation depending on the firearm and ammunition used. Various types of firearms, modern firing mechanisms and ammunition will be explained, together with an introduction to the physical concepts underpinning the four main constituents of the term ballistics; internal, intermediate, external and terminal ballistics. Wound ballistics is a sub-set of terminal ballistics and is specifically discussed to put the physical and chemical scientific concepts into context of forensic veterinary practice. The collection of firearms evidence from an animal and the surrounding crime scene is also considered to explain to practitioners the importance of sending this evidence for further forensic examination and analysis

Practitioner Collaborations and Professional Development in Forensic Science

An overview of the collaborative international research I undertake with forensic practitioners and the professional development opportunities available for forensic science practitioners

Corroded Firearms: The Non-Destructive Approach

Recovery of corroded and damaged firearms can pose a problem to a range of professionals including law enforcement, border control, firearms examiners and archaeologists. Depending on the nature of damage and extent of corrosion the firearms can be completely seized and potentially unidentifiable using traditional visual examination alone. This difficulty impacts upon the ability to undertake legal classification and ensure safe recovery and transportation of the artefacts. This paper details the use of rapid, non-destructive x-ray systems for the internal examination of a range of corroded weapons. Research has shown that weapons can be identified using visual comparison of firearm’s internal components and can determine whether fired or live ammunition is still housed inside. Such methods of examination could also be applied to the identification of ammunition, converted and concealed weapons as well as illustrate the potential for intelligence gathering at border control points to further detect smuggling of firearms and/or firearm components

Student mentoring to enhance graduates’ employability potential

This paper considers whether the adoption of a subject-specific, classroom-based, voluntary extra-curricular student mentoring scheme could provide an effective mechanism and andragogic approach to enhance higher education students’ employability potential pre-graduation. Over the three-year pilot, 26 more advanced (second to fourth year) undergraduate students actively mentored nearly 400 first year undergraduate students during workshops delivered annually within forensic and policing focused courses. In total, 17 mentors anonymously completed online, post-scheme surveys. Survey data was qualitatively and quantitatively analysed to evaluate the scheme, establish which skills and attributes mentors had developed and investigate whether mentors could appropriately identify example skills within professional terminology used during employer recruitment. In addition, this paper reflects on the implementation of remote student mentoring during the COVID-19 pandemic and its adoption within a blended learning framework. The results from this research strongly support mentoring as an effective mechanism to develop undergraduate employability skills, significantly developing mentors’ self-confidence and self-efficacy in their interpersonal and communication skills. Although mentors were aware of university graduate attributes and thought they could evidence these with appropriate examples, in practice this was not necessarily the case. As a result, a framework is proposed to enable mentors to identify their skills and how they may align with competencies sought by relevant forensic and policing employers. Although, other andragogic practices may need to be implemented to maximise the potential for successful graduate employment

Research4Justice: An International, Open Access Research Database

Introduction: Over recent years, formal partnerships have been established between law enforcement, forensic practitioners and academic institutions, facilitating knowledge exchange in the criminal justice system. However, justice system related research is both multi and interdisciplinary, with a significant proportion of research remaining unpublished and inaccessible to practitioners internationally. This research includes student outputs and in 2017, a clear mandate was provided by both practitioners and researchers to develop an open access, multi-discipline repository of undergraduate and postgraduate research relevant to any aspect of the justice system. Aims: The Research4Justice repository therefore aims to: - Provide a free, easily searchable database for academics to deposit and practitioners to access relevant research undertaken in higher education institutions; - Facilitate institutional collaboration and networking across academia and industry; - Support research and development in any discipline relevant to the justice system; - Share standardised approaches and increase availability of robust data for use in court; - Minimise research repetition and build larger, statistically valid datasets for use and application to support casework. Material & methods: The database has been developed in partnership with Jisc, a provider of digital solutions in higher education, as well as practitioners and professional bodies from a range of disciplines. Research outputs include thesis/dissertations, literature reviews, reports, posters and presentations from disciplines such as forensic and crime science, policing, medicine and nursing, criminology, psychology and law. Results: This presentation will provide an introduction to the Research4Justice repository with a live demonstration, discuss the benefits and limitations for practitioners, researchers and academics, and highlight future repository developments. Following the presentation there will be the opportunity to explore the online resource and provide user feedback to the presenting author

Empirical evaluation of spring powered air rifle storage and modifications on forensic practice and casework

Air weapons are commonly used by civilian populations across the world, particularly by those under 18, and discharges often result in desecration, criminal damage and animal abuse. Online forums and websites provide an accessible resource for civilians to access airgun modification methods proposing to increase muzzle velocity. However, there is limited published research that empirically evaluates the impact of air weapon modification and the potential to influence casework interpretation. Therefore, this paper aims to initiate such research by quantifying the effect of storage conditions (mainspring compression and oil travel/dieseling) and two modifications (reduction of barrel length and preloading through addition of washers) encountered in casework on recorded muzzle velocities using a small number of break barrel, spring powered air rifles. Storing airguns vertically and/or cocked statistically effected the consistency of air pellet discharge and recorded muzzle velocities. Modifications typically resulted in significant variation in air rifle muzzle velocities, often with unfavourable side effects and/or to the detriment of the airgun. Deliberately reducing barrel length or incorporating preload demonstrated the greatest impact on muzzle velocity; however, the direction of muzzle velocity change could not be predicted by air rifle calibre, brand or model. This preliminary study reinforces the requirement for practitioners to undertake timely weapon examinations and interpret casework on a case-by-case basis, especially for modified airguns. In addition, this research strongly recommends the re-evaluation of current air weapon storage and/or testing procedures to ensure accurate and reliable interpretations are obtained for legal classification and casework

Forensic comparison of fired cartridge cases: Feature-extraction methods for feature-based calculation of likelihood ratios

We describe and validate a feature-based system for calculation of likelihood ratios from 3D digital images of fired cartridge cases. The system includes a database of 3D digital images of the bases of 10 cartridges fired per firearm from approximately 300 firearms of the same class (semi-automatic pistols that fire 9 mm diameter centre-fire Luger-type ammunition, and that have hemispherical firing pins and parallel breech-face marks). The images were captured using Evofinder®, an imaging system that is commonly used by operational forensic laboratories. A key component of the research reported is the comparison of different feature-extraction methods. Feature sets compared include those previously proposed in the literature, plus Zernike-moment based features. Comparisons are also made of using feature sets extracted from the firing-pin impression, from the breech-face region, and from the whole region of interest (firing-pin impression + breech-face region + flowback if present). Likelihood ratios are calculated using a statistical modelling pipeline that is standard in forensic voice comparison. Validation is conducted and results are assessed using validation procedures and validation metrics and graphics that are standard in forensic voice comparison

Forensic comparison of fired cartridge cases: Feature-extraction methods for feature-based calculation of likelihood ratios

We describe and validate a feature-based system for calculation of likelihood ratios from 3D digital images of fired cartridge cases. The system includes a database of 3D digital images of the bases of 10 cartridges fired per firearm from approximately 300 firearms of the same class (semi-automatic pistols that fire 9 mm diameter centre-fire Luger-type ammunition, and that have hemispherical firing pins and parallel breech-face marks). The images were captured using Evofinder®, an imaging system that is commonly used by operational forensic laboratories. A key component of the research reported is the comparison of different feature-extraction methods. Feature sets compared include those previously proposed in the literature, plus Zernike-moment based features. Comparisons are also made of using feature sets extracted from the firing-pin impression, from the breech-face region, and from the whole region of interest (firing-pin impression + breech-face region + flowback if present). Likelihood ratios are calculated using a statistical modelling pipeline that is standard in forensic voice comparison. Validation is conducted and results are assessed using validation procedures and validation metrics and graphics that are standard in forensic voice comparison

What are the Prospects of 3D Profiling Systems Applied to Firearms and Toolmark Identification?

This paper details a comparative pilot study of 3D (three dimensional) imaging technologies for potential application in forensic firearms and toolmark identification; as such it reviews the most up-to-date profiling systems. In particular, the paper focuses on the application of 3D imaging and recording technology as applied to firearm identification, being a specialised field within the discipline of toolmark identification. Each technology under test employs a different technique or scientific principle to capture topographic data i.e. focus-variation microscopy, confocal microscopy, point laser profilometry and vertical scanning interferometry. To qualitatively establish the capabilities and limitations of each technology investigated, standard reference samples were used and a set of specific operational criteria devised for successful application in this field. The reference standard crucially included and centred on was the National Institute of Standards and Technology (NIST) 'standard bullet'. This was to ensure that evaluation represented the practical examination of ballistic samples i.e. fired cartridge cases and bullets. It is concluded that focus-variation microscopy has potentially the most promising approach for a forensic laboratory instrument, in terms of functionality and 3D imaging performance, and is worthy of further investigation

Proof of Life: Mark-Making Practices on the Island of Alderney

Currently, mark-making practices as a form of identification and proof of life are an unrealized resource. Over a three-year period, systematic walkover surveys were conducted on and within fortifications and other structures on the island of Alderney to locate historic and modern marks. The investigations presented in this article demonstrate the importance of non-invasive recording and examination of marks to identify evidence connected to forced and slave labourers, and soldiers present on the island of Alderney during the German occupation in World War II. Names, hand and footwear impressions, slogans, artworks, dates, and counting mechanisms were recorded electronically and investigated by using international databases, archives, and translation services. We discuss the value and challenges of interpreting traces of human life in the contexts of conflict archaeology and missing person investigations and underline the need for greater recognition of marks as evidence of past lives