Browsing by Author "Mole, Calvin Gerald"

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    The analysis of the artefacts produced by forensically significant blowfly (Diptera: Calliphoridae) activity and their effect on bloodstain pattern analysis
    (2016) Lesaoana, Mpasi Pascalis; Heyns, Marise; Mole, Calvin Gerald
    Violent crimes involving bloodshed may result in bloodstains spattering on the surrounding surfaces. Accurate analysis of bloodstains at the scene can provide investigators with insights into the series of events that occurred during the execution of a violent crime. At a crime scene, blowflies feed on bloodstains and deposit artefacts that may cause confusion during crime scene reconstruction. Experimental cages of two possible crime scene surfaces (paper to simulate wallpaper and linoleum) were developed such that fly artefacts can be characterized and differentiated from legitimate bloodstains. Pooled bloodstains were created within the experimental cages and blowflies were allowed access to the cages. A total of 10739 and 740 artefacts deposited on paper surfaces and linoleum walls respectively were examined. Clear differences between fly artefacts and legitimate bloodstains were noted and unique characteristics of fly artefacts resembling true blood spatters with a possibility of confounding crime scene reconstruction were distinguished.
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    Entomological examination of the relationship between ante-mortem and post-mortem amitriptyline concentrations in insects
    (2016) Sanyanga, Taremekedzwa; Heyns, Marise; Mole, Calvin Gerald
    When the death of an individual has occurred, the body of the deceased is not always discovered immediately and at times the body may be discovered after a long period of time. The consequence of discovering a body after a long period of time is that the body maybe found severely decomposed or skeletonized. As a result no viable blood, urine or tissue samples may exist that can be collected and utilized in toxicological analyses. Entomotoxicology offers a supplementary method to detect and analyse the presence of drugs post-mortem, especially in cases where viable toxicological specimens such as human tissue cannot be obtained. In South Africa and globally, standardised methodology is required to perform entomological examinations accurately, however due to the large variation of experimental set-up no such standardised methods yet exist. The main aim of the research was to analyse the effect of Amitriptyline on the development and growth rate of forensically important blow flies, and to investigate the potential in using blow fly larvae of the Western Cape, South Africa in forensic entomotoxicological analyses and future implementation. To achieve this blow fly species C. chloropyga and L. sericata were reared on homogenised pig liver containing 1000 mg/kg Amitriptyline until emergence of imago. The duration of time taken by the blow fly larvae species to reach 1 st , 2 nd , 3 rd , pupae and imago growth stages in the presence and absence of Amitriptyline was noted. The presence of drugs in larvae was investigated using high-pressure liquid chromatography coupled with dual mass spectrometry (HPLC/MS-MS). Amitriptyline was detected in all experimental larvae samples and was found to delay pupation by at least 26 hours and imago emergence by at least 72 hours. Amitriptyline however showed no distinct effect on C. chloropyga length and mass but was associated with a smaller length and mass in L. sericata compared to controls. Results indicate that entomotoxicology can be of use for qualitative analysis for the presence of Amitriptyline in forensic cases. Results also highlight the unpredictability of research using biological specimens.
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    Investigation of wound characteristics and the force associated with skull fracture due to impact by a hammer
    (2014) Mole, Calvin Gerald; Heyns, M
    Death due to cranial blunt force trauma is a major issue not just in South Africa but worldwide. The vast majority of studies conducted on cranial blunt force trauma have analysed trauma to the frontal portion of the head. This is due to the involvement of the frontal portion of the head in automotive accidents. The lateral portion of the head is however no less important and is often impacted during homicidal assault. In cases involving cranial blunt force trauma, a common question asked of experts relates to the amount of force involved with a particular trauma. The goal of forensic science in general is to provide objective, repeatable results. At present, however, answering this question relies on a subjective rating scale of mild, moderate or severe force. Determining the severity of the force is also subjective, in that it relies heavily on the experience of the expert. Forensic anthropology by its nature is often subjective; however there is a need to move away from conducting analyses based predominantly on the experience of the investigator. With this in mind, this dissertation offers background information on fracture mechanics and impact biomechanics and provides a current review of the literature surrounding lateral impact to the skull. The research conducted as part of this dissertation attempts to quantify the force and energy involved with lateral impact to the skull due to a blow by a hammer, as well as describes the wound morphology associated with such impacts. Human tissue for experimentation is becoming increasingly difficult to acquire. There is therefore a need to determine suitable models for use in such testing. In the current study whole porcine heads were impacted on the fronto-parietal portion of the cranium. Half of the specimens were impacted with an implement resembling the shape and weight of a hammer. These hammer tests were conducted primarily to determine the type of trauma associated with such impacts and determine if a correlation exists between velocity or energy of impact and the level of trauma sustained. The remaining specimens were impacted with a Hopkinson pressure bar of the same diameter as the striker in the hammer tests. The Hopkinson pressure bar apparatus allows for the determination of the force of impact. The use of the Hopkinson pressure bar to determine fracture forces in whole specimens is novel. The fracture forces obtained in the current study agree considerably with the literature previously published on lateral, cranial blunt force trauma to both human and porcine specimens. The fractures produced, however, are atypical and may indicate a need to conduct further tests on other animal models.
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    Patterns of death due to blunt force trauma in the West Metropole of the City of Cape Town, South Africa
    (2015) Clark, Courtnee; Mole, Calvin Gerald; Heyns, Marise
    There is currently a paucity of information regarding the prevalence and characteristics associated with blunt force trauma related homicides in South Africa. Information relating to the patterns of blunt force trauma could assist in the implementation of appropriate interventions targeted at specific areas or individuals. Furthermore, it can direct research toward topics in blunt force trauma which are in need of investigation. As such the primary objective of this study was to determine the prevalence of blunt force trauma related homicides in the West Metropole of the City of Cape Town, South Africa. The secondary objective was to describe the characteristics associated with blunt force trauma related homicides in the West Metropole of the City of Cape Town, South Africa. This thesis begins by defining blunt force wounds and comparing and contrasting the prevalence and documented characteristics associated with blunt force trauma nationally as well as internationally. Blunt force wounds occur when the body comes into contact with a blunt object at great force. Homicides by blunt force trauma are usually the result of assaults with fists, feet, bats or clubs, etc. Common wounds associated with blunt force assaults are contusions, lacerations and in some cases, bone fractures. In fatal blunt force assaults, these wounds tend to be located primarily on the head region. Salt River Mortuary receives cases from the West Metropole of the City of Cape Town, hence the results of this thesis are considered in the context of this area. This region is comprised of areas with diverse socio-economic status' and heterogeneous crime rates. The study was a retrospective review of autopsy reports obtained from Salt River mortuary from 1 January 2013 to 31 December 2014. The prevalence of blunt force trauma was considered for unnatural deaths with a focus on homicide. The inclusion criteria were cases where the cause of death was blunt force trauma as determined by the pathologist. Cases in which the death was not caused solely by blunt force trauma were classified as combination deaths, and cases involving deaths due to blunt force trauma as a result of falling from a height, train-related, pedestrian or motor vehicle accidents were excluded. A total of 3346 and 3461 cases of unnatural deaths occurred in the West Metropole of the City of Cape Town in 2013 and 2014 respectively. 247 (7.4%) cases in 2013 and 277 (8%) cases in 2014 involved blunt force injuries, and of these cases 183 (5.5%) in 201 3 and 201 (5.8%) in 2014 were classified as homicides. The results of the characteristics of blunt force homicide analysed in this study broadly concur with previous studies undertaken in South Africa, with some areas of divergence. Additional features that have not been extensively covered in previous studies also emerged, which could possibly form the basis for future investigations.