Abstract:
Over the last three decades, several high-profile exonerations have shattered the individualisation fallacy of the traditional feature-comparison forensic sciences. These cases exposed severe shortcomings in the scientific reliability and validity of the pattern evidence disciplines and prompted a fundamental shift in the paradigm of the pattern evidence disciplines—including bloodstain pattern analysis. In order for the discipline of bloodstain pattern analysis to successfully shift its approach from subjective to objective methodologies, quantitative data from high-quality and reliable empirical research is needed. In this work, a collection of drip bloodstain patterns was generated for a range of droplet fall heights, number of droplets applied to the impact site and distances between the impact site and vertical targets. The data derived from image analyses of the generated patterns indicated imposed variation in these parameters influenced the quantitative characteristics of the resulting drip patterns, with differences observed in the stain number, size, distribution and shape. Accordingly, this thesis makes a significant and original contribution towards quantification of drip bloodstain patterns and the parameters that govern their appearance. Furthermore, this thesis contains material concerning the development and testing of a brachial artery device for the purposes of generating arterial spurt patterns resembling those observed in casework. A limited number of patterns created during preliminary attempts at validation suggested the device was capable of producing different spurt-like patterns through modification of its individual components. Additionally, these patterns were found to resemble bloodstain patterns from crime scenes classified by analysts as resulting from arteriallyprojected mechanisms.