Ballistics Image Processing and Analysis for Firearm Identification

Firearm identification is an intensive and time-consuming process that requires physical interpretation of forensic ballistics evidence. Especially as the level of violent crime involving firearms escalates, the number of firearms to be identified accumulates dramatically. The demand for an automatic firearm identification system arises. This chapter proposes a new, analytic system for automatic firearm identification based on the cartridge and projectile specimens. Not only do we present an approach for capturing and storing the surface image of the spent projectiles at high resolution using line-scan imaging technique for the projectiles database, but we also present a novel and effective FFT-based analysis technique for analyzing and identifying the projectiles

Physical and chemical trace evidence from 3d-printed firearms, and use of a quadcopter for targeted sampling of gaseous mercury in the atmosphere

My forensic research resulted in the first peer-reviepaper to address the forensic challenges presented by 3D-printed polymer firearms. The work involved a systematic approach to the analysis of evidence stemming from 3D-printed firearms filling a critical void in current forensic knowledge. We used DART-MS to characterize the polymer evidence left behind by 3D-printed firearms as well as an evaluation of pre-existing firearm and toolmark techniques and fingerprint analysis. We demonstrated that 3D-printed firearms leave behind characteristic polymer residue on cartridge cases bullets and the receiving surface which can be identified using DART-MS. The culmination of the work includes a database / reference library that can give forensic practitioners the ability to identify and source unknown polymer evidence using chemometric analysis including principle component analysis (PCA) and ongoing work with supervised statistical classification methods. Several novel analytical methods were developed in the course of this dissertation work including forensic analysis of trace chemical evidence from 3D-printed firearms using direct analysis in real time-mass spectrometry (DART-MS) and targeted aerial sampling for quantitation of gaseous mercury. The mercury project utilized a quadcopter unmanned aerial vehicle (UAV) and gold-coated quartz sorbent tubes to target and capture gaseous mercury which was then quantified both in the laboratory and in the field using cold vapor atomic fluorescence spectrometry (CVAFS). This method was verified to effectively capture and quantify mercury in the atmosphere near point sources and was applied near a coal-fired power plants petroleum refinery and municipal landfill. Average concentrations (± standard deviation) immediately downwind of the landfill were higher at ground level and 30 m compared to 60 m and 120 m (5.3 ± 0.5 ng m-3 5.4 ± 0.7 ng m-3 4.2 ± 0.7 ng m-3 and 2.5 ± 0.3 ng m-3 respectively). Concentrations were also higher at an urban/industrial area (Memphis) (3.3 ± 0.9 ng m-3) compared with a rural/background area (1.5 ± 0.2 ng m-3). Overall we shothe method is useful to probe Hg concentrations aloft and quantify emissions from potential point sources in the field using an inexpensive quadcopter and sampling setup. The forensic research was funded by NIJ Graduate Research Fellowship (Award # 2017-IJ-CX-0001). The opinions findings and conclusions or recommendations expressed here are those of the authors and do not necessarily reflect those of the U.S. Department of Justice

Correlation of distance and damage in a ballistic setting

Forensic Investigation is a discipline which relies on various fields in order to be able to reconstruct an incident. Forensic Ballistics focuses upon the mechanics of projectile launch, flight and the effects of the projectile when impacting a target as well as firearms and ammunition. One of the most common evidence types in firearms related events is Gun Shot Residue (GSR), where typical analysis methods involves chemical confirmatory tests. Therefore, the fields traditionally associated with forensic ballistics are chemistry and physics, however there are various other scientific fields which could potentially further knowledge in this area such as radiography and computational science. Arguably one of the most important considerations within Forensic Ballistics is the ability to accurately reconstruct an incident. Currently there is limited literature aimed at understanding GSR spread at distances above 15 metres, which is a limitation for the criminal justice system (chapter 1). This work aims to further this knowledge by gaining an understanding of GSR spread at various distances, both short and long range (chapter 4), whilst combining this with Gun Shot Wound (GSW) damage using radiography (chapter 3). The data obtained will then be used for computational modelling with the aim of predicting shooter distance (chapter 5)

LAW ENFORCEMENT RISK MODEL TO COMBAT OPIOID RECIDIVISM

Bergen County, New Jersey, has seen opioid-related overdoses and deaths spike in the last few years. One of the challenges in addressing this epidemic is that “at-risk” individuals may encounter multiple segmented domains such as law enforcement, recovery services, and healthcare institutions, but no one agency has oversight of all the contacts. Each encounter with at-risk populations, including those who suffer from opioid addiction or who may recidivate, becomes a data record in a system. This thesis asks how can law enforcement leverage such data sets to address the opioid epidemic and battle recidivism? This research examined law enforcement arrest data and overdose reporting in Bergen County, analyzing which risk factors in recidivism could be discerned using statistical information, cross-tabulations, Pearson’s chi-squared tests, and data modeling from the Cox proportional hazards model. The results showed that no demographic profile was more likely to have another overdose or death, and theft arrests coincided with a decreased chance of overdose, despite law enforcement’s presumption of the contrary. The strongest predictor of an overdose was a prior overdose, with the risk increasing for each additional overdose. Additionally, having any contact with law enforcement was an indicator of a significantly higher chance of overdose or death. Thus, each interaction between law enforcement and an observed opioid abuser is a critical point for intervention.Civilian, Bergen County Prosecutor's Office New JerseyApproved for public release. Distribution is unlimited

Open-source implementation of the Congruent Matching Cells method for cartridge case identification

Firearm evidence identification is the process of analyzing bullets or cartridge cases left at a crime scene to determine if they originated from a particular firearm. Statistical methods have long been developed and used to aid in such analyses. The Congruent Matching Cells (CMC) method is one such method developed at the National Institute of Standards and Technology (NIST) to quantify the similarity between two spent cartridge cases based on the markings left by the firearm barrel during the firing process. We introduce the first open-source implementation of the CMC method in the R package cmcR. The package will bolster forensic researchers\u27 abilities to investigate, validate, and improve upon current statistical methodology in the field of forensic science

The characterisation and provenance of ammunition components

© Cranfield University, 2018The objective was to create a comprehensive data set of analytical results relating to the physical construction and chemical composition of ammunition components; to be used to determine the provenance of ammunition. The study focusses on 7.62 x 39 mm ammunition due to its ubiquitous nature in crime and conflict zones around the world. Ammunition identification and classification currently relies heavily on the information provided on cartridge case headstamps and packaging. In the absence of this information, there is no definitive method to ascertain the potential origin of ammunition. The aim of this study was to examine the physical and chemical composition of ammunition components from different origins in an attempt to establish if the construction and elemental composition of these components could be used to differentiate between sources of ammunition. Initially, various physical and chemical techniques were employed to analyse samples of ammunition from known sources. Currently, there are 24 known countries and 42 known manufacturers who produced 7.62 x 39 mm ammunition (Ness and William, 2011). This study aimed to analyse a representative sample of 7.62 x 39 mm ammunition to determine if differentiation between the manufacturers is feasible. A further temporal study was explored to establish if differences in the materials and manufacturing techniques occurred in a single manufacturing plant over a period of time. A detailed analysis of ammunition components generated information pertaining to differences particular to each manufacturer’s ammunition. It is reported that there are sufficient distinguishing features between the 7.62 x 39 mm ammunition analysed, and can be said with a degree of certainty that a particular round of 7.62 x 39 mm ammunition could have originated from a particular manufacturer. This research was conducted with the ambition of creating a publication to be used by professionals and academics in relation to identification of ammunition origin. Working with Cranfield University to contribute to work conducted by national and international organisations it is presented as a database set; to be used as a reference where standard forensic techniques currently provide no information of the provenance ammunition origin. Promising results provide avenues for further research to be continued temporally or even into other calibres – ultimately comprising of a resource that is invaluable to many

Modified Firearm Discharge Residue Analysis utilizing Advanced Analytical Techniques, Complexing Agents, and Quantum Chemical Calculations

The use of gunshot residue (GSR) or firearm discharge residue (FDR) evidence faces some challenges because of instrumental and analytical limitations and the difficulties in evaluating and communicating evidentiary value. For instance, the categorization of GSR based only on elemental analysis of single, spherical particles is becoming insufficient because newer ammunition formulations produce residues with varying particle morphology and composition. Also, one common criticism about GSR practitioners is that their reports focus on the presence or absence of GSR in an item without providing an assessment of the weight of the evidence. Such reports leave the end-used with unanswered questions, such as “Who fired the gun?” Thus, there is a critical need to expand analytical capabilities and enhance the impact of the forensic scientist’s conclusions. To maximize the evidential value of GSR evidence, detection methods exploiting modern advancements in instrumentation must be explored and developed. This collection of work reviews the current literature review and illustrates a trend to investigate emerging methods to enhance IGSR analysis with a wider emphasis on OGSR compounds. Combining IGSR and OGSR components increases the confidence of detecting GSR on a collected sample. Overall, the development of novel analytical methods for GSR detection, the application of ground-breaking statistical methods to interpret GSR evidence using artificial intelligence (neural networks) and likelihood ratios to estimate the weight of the evidence, and the understating of the host-guest chemistry of GSR species is anticipated to provide a needed leap of knowledge in the community

A critical review of the current state of forensic science knowledge and its integration in legal systems

Forensic science has a significant historical and contemporary relationship with the criminal justice system. It is a relationship between two disciplines whose origins stem from different backgrounds. It is trite that effective communication assist in resolving underlying problems in any given context. However, a lack of communication continues to characterise the intersection between law and science. As recently as 2019, a six-part symposium on the use of forensic science in the criminal justice system again posed the question on how the justice system could ensure the reliability of forensic science evidence presented during trials. As the law demands finality, science is always evolving and can never be considered finite or final. Legal systems do not always adapt to the nature of scientific knowledge, and are not willing to abandon finality when that scientific knowledge shifts. Advocacy plays an important role in the promotion of forensic science, particularly advocacy to the broader scientific community for financial support, much needed research and more testing. However, despite its important function, advocacy should not be conflated with science. The foundation of advocacy is a cause; whereas the foundation of science is fact. The objective of this research was to conduct a qualitative literature review of the field of forensic science; to identify gaps in the knowledge of forensic science and its integration in the criminal justice system. The literature review will provide researchers within the field of forensic science with suggested research topics requiring further examination and research. To achieve its objective, the study critically analysed the historical development of, and evaluated the use of forensic science evidence in legal systems generally, including its role regarding the admissibility or inadmissibility of the evidence in the courtroom. In conclusion, it was determined that the breadth of forensic scientific knowledge is comprehensive but scattered. The foundational underpinning of the four disciplines, discussed in this dissertation, has been put to the legal test on countless occasions. Some gaps still remain that require further research in order to strengthen the foundation of the disciplines. Human influence will always be present in examinations and interpretations and will lean towards subjective decision making.JurisprudenceD. Phil

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