Thesis (M. Sc.)--University of Canterbury, 2006. / Typescript (photocopy). Includes bibliographical references (leaves (184-185). Also available via the World Wide Web.

published_or_final_version / abstract / toc / Statistics and Actuarial Science / Master / Master of Philosophy

published_or_final_version / Statistics and Actuarial Science / Doctoral / Doctor of Philosophy

Blood is one of the most common and important types of physical evidence present at a crime scene. When liquid blood is acted upon by external physical forces, that blood is often distributed through the air in the form of droplets, with bloodstains and bloodstain patterns deposited on adjacent surfaces. Using the mathematical relationship that exists between the blood droplet and resultant bloodstain’s length and width ratio, the angle at which the blood droplet impacted the receiving surface can be determined. Using this relationship, it becomes possible for Bloodstain Pattern Analysts to determine the three dimensional Region of Origin for the blood source from which the bloodstains under examination have originated. A Bloodstain Pattern Analyst performs angle of impact calculations from bloodstains for the purpose of making a three dimensional determination of blood source Region of Origin. The reliability of that determination is based on an assumption that one of the most important biological properties of blood; the amount of red blood cells or hematocrit value, has no influence over the length to width ratio of a bloodstain. As a consequence the Impact angle = arcsine [width/length] calculation has been assumed accurate regardless of the 'unknown' hematrocrit value. This thesis investigated the effect of the hematocrit value on the angle of impact calculation and thus the ability to determine the three dimensional blood source Region of Origin. Bloodstains were created by releasing a series of 18µL droplets, with ten different hematocrit values, onto a ceramic tile at four different angles. The resultant bloodstain length and width was measured and impact angle calculated. Evaluation of the research data shows that the hematocrit value significantly affects the bloodstains length and width. However, it is apparent that there is close agreement between the known and calculated impact angles irrespective of the hematocrit value.

This dissertation consists of five chapters, each of which focuses on various aspects of the forensic discipline of Firearms and Toolmarks. This dissertation for the most part attempts to highlight the exposure of projectiles to blood and the degradation over time of the fine detail, which is necessary for microscopic examination. This study should be of interest to students and qualified role-players in forensic science, the criminal justice system, the law community and the general population globally. Chapter 1 identifies the research problem and the necessary steps that were taken to ensure that the research methodol.ogy applied is relevant and reliable. Chapter 2 focuses on various factors that have to be considered in damage to bullets and investigation procedures that should be followed to ensure that physical evidence is preserved for submitting to a forensic science laboratory. Chapter 3 investigates the degradation effects of fired bullets exposed to various materials in a laboratory environment and the timelines associated with the degradation effects. Chapter 4 evaluates the examination procedures for fired bullets and the contributing factors that may influence the striation marks on bullets needed for microscopic examination. It also examines the scientific method used for firearm identification, and explores the admissibility of physical evidence in a court of law. The final chapter, Chapter 5 discusses the findings and recommendation of this research study. / Criminology / M. Tech. (Forensic Investigation)

This dissertation consists of five chapters, each of which focuses on various aspects of the forensic discipline of Firearms and Toolmarks. This dissertation for the most part attempts to highlight the exposure of projectiles to blood and the degradation over time of the fine detail, which is necessary for microscopic examination. This study should be of interest to students and qualified role-players in forensic science, the criminal justice system, the law community and the general population globally. Chapter 1 identifies the research problem and the necessary steps that were taken to ensure that the research methodol.ogy applied is relevant and reliable. Chapter 2 focuses on various factors that have to be considered in damage to bullets and investigation procedures that should be followed to ensure that physical evidence is preserved for submitting to a forensic science laboratory. Chapter 3 investigates the degradation effects of fired bullets exposed to various materials in a laboratory environment and the timelines associated with the degradation effects. Chapter 4 evaluates the examination procedures for fired bullets and the contributing factors that may influence the striation marks on bullets needed for microscopic examination. It also examines the scientific method used for firearm identification, and explores the admissibility of physical evidence in a court of law. The final chapter, Chapter 5 discusses the findings and recommendation of this research study. / Criminology and Security Science / M. Tech. (Forensic Investigation)

The success or failure of any criminal investigation often depends on the recognition of physical evidence left at a crime scene and the proper analysis of that evidence. Crime scenes that involve bloodshed often contain a wealth of information in the form of blood patterns, the location, and its cause. Any criminal investigation has specific tasks, from the time when the crime is reported to the reconstruction of crime scenes. A lot of work needs to be done. Once the investigation starts at the crime scene, BPA needs to be done at the crime scene and the investigating officer must identify this evidential tool. The investigating officer should not necessarily have specialised training in blood pattern analysis, but rather know when to use these experts at their bloody crime scenes. With the interviews and docket analysis done, the researcher found that this was a problem as the investigating officers, either had no knowledge on the subject of BPA or very little knowledge on this research. The purpose of this study was to determine the use of BPA to CSR, and for the investigating officer to realise that it is not just a bloody crime scene, but also contains a wealth of evidence. The researcher had two research questions. Once the investigating officer follows the objectives of criminal investigation, they should be able to have a strong case against the perpetrators. How could BPA be used in the reconstructing of a crime scene? The researcher wanted to bring it to the investigating officers’ attention that it is not just a bloody crime scene, but rather that it contains a wealth of evidence, which can give them a perspective of the movement of both the victim and perpetrator during the commencement of the crime. Regardless of the lack of knowledge of BPA, it is proposed that investigating officers are to be informed, either through station lectures or by yearly refresher workshops and courses of the evidential tool of BPA. When the bloody crime scene is reconstructed with the use of BPA, an insight of what transpired at the crime scene will help them to finalise their cases. For recommendations, it is proposed that investigating officers are to be trained in more in depth courses in criminal investigation as well as crime scene reconstruction and evidence collection using FSL. / Criminology and Security Science / M.Tech. (Forensic Investigation)