No description available.

No description available.

No description available.

As one form of valuable forensic evidence, the shoeprint marks left at crime scenes have often been ignored. This has now changed as footwear marks are more likely to be recovered from some crime types than fingerprints. Compared to conventional biometric evidence such as DNA traces and fingerprints, it is harder for suspects to conceal their shoeprints. To improve the utilization of footwear impressions in forensic investigations and boost the analysis speed, shoeprint recognition systems have been recently reported. However, without the capability of tackling shoeprints left by the same shoes in different worn conditions, current shoeprint recognition systems may suffer considerable performance degradations in real-world application. We believe that a shoeprint recognition system capable of using 3D depth information from footwear outsoles to produce 2D shoeprints with expected worn specifications is a practical solution to these limitations. In this thesis, an enhanced hybrid method is proposed for 3D outsole feature classification and extraction. By carrying out analysis in terms of curvature and frequency attributes, our proposed method is able to categorize 3D outsole features into two types - Printable and Unprintable 3D Features, according to their contribution in leaving 20 impressions on a surface, and produce initial extraction results. Finally, such rudimentary results are refined by a watershed-based post-processing algorithm to produce elaborate 2D shoeprints. The superior performance of this proposed algorithm is confirmed by both synthetic and real outsole based experiments under various distortions. To exploit the utilization of 20 shoeprints extracted from the 3D outsole models in real world applications, an image patch-based system for shoeprint matching is also proposed. In this method, a mutually collaborative approach is proposed and - 1 - employed for the image patch binarisation operation. With the assistance of the shape context approach and the coherent point drift ((PD) method, skeletons derived from the extracted 2D shoeprint and a grayscale image in the reference database are aligned, and the relevant result is used to evaluate the similarity between these two images. Tested under various distortions, the proposed system demonstrates the feasibility of matching binary shoeprint images to their grayscale counterparts. Finally, this thesis offers some suggestions for future research in this field. ·2·

No description available.

The field of forensic drug testing is continually changing with analytical methodology being developed for an increasing number of drugs in a variety of biological matrices. The aim of this thesis was to develop a novel enzyme immunoassay (EIA) for screening oral fluid specimens for the presence of anhydroecgonine methyl ester (AEME), a pyrolysis product of cocaine. A confirmatory method was also to be developed to accurately quantify the levels of cocaine, its metabolites and pyrolysis products in oral fluid samples. The immunoassay development was started by synthesising an immunogen using anhydroecgonine (AE) and thyroglobulin. Following immunisation the antisera were screened by enzyme linked immunosorbent assay (ELISA) to enable selection of the antibody with the highest specificity and sensitivity. An enzyme labelled drug was synthesised and the titres of antibody and enzyme were optimised. A series of validation experiments were carried out which concluded that the EIA was sensitive, highly specific, and precise. Gas chromatography-mass spectrometry (GC-MS) was investigated for the quantitation of cocaine and its metabolites. A temperature program was selected which allowed for the simultaneous analysis of all the analytes. A solid phase extraction (SPE) method was developed to extract cocaine and its metabolites from oral fluid. The SPE method provided high recovery for all analytes apart from the highly polar AE. Degradation of the GC column had a detrimental effect on the analysis of AEME, and so the confirmation method was switched to liquid chromatography-tandem mass spectrometry (LC-MS/MS). A series of LC columns and mobile phases were tested for optimum separation and ionisation. The instrument parameters such as capillary voltage, drying gas temperature, shield voltage, and needle voltage, were optimised. Following a number of validation experiments the method was found to be highly sensitive, precise, accurate and robust. Both the EIA and LC-MS/MS methods were applied to the analysis of clinical samples from self declared crack cocaine users. The EIA showed good correlation to LC-MS/MS. It was evident that the presence of AEME can positively identify smoking as the route of cocaine administration however its absence does not necessarily mean the individual has not smoked cocaine.

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)