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Understanding the mechanism of injury associated with long bone fractures through dynamic bending impactEmrith, Toshika Sheshna 28 February 2020 (has links)
Blunt force trauma may result from homicide and assault cases, child abuse and motor vehicle accidents. Such incidents often result in skeletal trauma. Trauma to the lower limbs due to bending forces often involves a fracture pattern known as a butterfly or wedge fracture. Forensic analysis of the butterfly fracture aids in the establishment of directionality of the force applied. Currently, forensic anthropologists employ a method dictating that the base of the butterfly fragment pertains to the side of impact, while the apex of the fragment pertains to the opposite side of impact. Recent studies have demonstrated that this theory leads to erroneous forensic reconstructions as it assumes that all butterfly fractures are produced due to bone failing in tension. Furthermore, it requires the presence of a detached piece in order to be applicable, which is also the case for other proposed methods. The current study explores the biomechanics involved in the production of butterfly fractures by conducting 3-point bending impacts through a drop apparatus. It also investigates the accuracy of current and proposed forensic methods and aims at establishing a more reliable method of inferring directionality from the fracture pattern. From the sample fractured in this study, 11.8% of the fractures produced were tension wedges and 14.7% were compression wedges. When applying the existing methods of inferring directionality to the fractured sample, the accuracies ranged from 5.9% to 59%, while the method developed during this study achieved an accuracy of 97.1%. These results highlight the need of considering compression wedges during forensic reconstructions and understanding the impact of employing methods conceptualised on the assumption that all butterfly wedges are produced in tension.
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Patterns of death due to blunt force trauma in the West Metropole of the City of Cape Town, South AfricaClark, Courtnee January 2015 (has links)
Includes bibliographical references / 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.
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The assessment of the utility and impact of sexual assault evidence collection kits (SAECKS) as DNA evidence in suspected cases of rapeCupido, Danielle January 2014 (has links)
The results from this study show the value of good basic medical practices in documentation of injuries, rather than more costly DNA evidence, in assisting courts in rape cases. However, the researchers do argue that in South Africa, as a middle-income country with a high percentage of non-intimate partner rapes, there would be an advantage in improving the system to collect and analyse DNA evidence rather than abandoning it completely. These results taken together suggest that DNA evidence can assist in signifying that sexual act has transpired however it is more likely that convictions will occur if evidence of physical injury is available, as DNA evidence cannot reveal if consent was obtained or not. As stated above South Africa has one of the highest rates of rape worldwide.
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Evaluating the role of DNA evidence in sexual offence cases in Zambia between 2007 and 2014Makasa, Innocent January 2017 (has links)
Zambia has reported high incidences of sexual abuse against women and children in recent years. Zambian law categorises sexual offences into; rape, defilement, incest and others, with defilement constituting the majority of the cases (>89%). Between 2010 and 2012, only <39% of defilement cases were taken to court, and convictions were achieved in only 13% of the cases reported to the police. Literature was reviewed to determine factors which contributed towards the resolution of criminal cases, and it was found that DNA evidence was prominent in resolving crimes, specifically as an identification tool in sexual offences. Currently there is no empirical evidence describing how DNA evidence has been used in resolving sexual crimes in Zambia. The causes of low prosecution and conviction rates have also not been investigated. A retrospective study was therefore conducted to evaluate the role of DNA evidence in sexual offence cases in Zambia, reported to eight major police stations in Lusaka between 2007 to 2014 (n=1154). Sexual offence cases comprised rape (n=74, 6.4%), defilement of a child under the age of sixteen years (n=1028; 89.1%), incest (n=7; 0.6%) and others (n=45; 3.9%). Only 14 (0.1%) of the cases had forensic samples collected in the form of a vaginal swab for the sole purpose of determining the presence of semen. In all cases where a suspect was identified (60%), identification was based on the witness/victim testimonies, and in no case was forensic DNA evidence used to assist in identification or corroborate the testimonies. Overall, 28.1% cases were taken to court and the conviction rate was 12.4%. If no injuries were observed on a victim aged between 0 - 5 years, the case was not taken to court. It was also observed that the younger the victim, the more likely the accused was not identified (p < 0.001), victims did not know the date of occurrence (p < 0.001), and the case was closed due to insufficient evidence. These findings support the use of employing forensic DNA evidence in sexual offence cases to aid the identification of suspects, either in the absence of witness/victim testimonies or alongside as corroborative evidence, which is hypothesised to increase the number of cases prosecuted in Zambia. At the time of this study there was no standardised protocol for the forensic investigations of sexual offences in Zambia, which to some extent, led to numerous missing data. Development and use of the national protocol and use of a validated sexual assault evidence collection kit may help mitigate the deficiencies and inconsistencies witnessed during this study.
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Constructing a DNA profile frequency database for South Africa using the Qiagen Investigator 24plex GO! KitNel, Lorraine January 2018 (has links)
DNA profiling is routinely used in the forensic setting to identify individuals during criminal and medico-legal investigations. Its principle is based on the molecular analysis of DNA to produce a string of alpha-numeric characters which can be matched to a known reference sample. The use of allele frequencies from the background population aids the statistical interpretation of a match and can be used to calculate the random match probability. In South Africa, allele frequency data for the background population is currently limited, which can hinder the discriminatory value of DNA evidence, particularly when only a partial profile is obtained. Therefore, the aim of this study was to generate DNA allele frequency data for four South African population groups using the QIAGEN Investigator® 24PLEX GO! Kit, which has six markers for which data does not yet exist for the South African population. Full forensic DNA profiles were generated from 655 unrelated individuals from four population groups in South Africa: Black African (n = 172), Coloured (n = 195), Indian/Asian (n = 88) and White (n = 200). A 98% first time success rate was observed using the direct PCR approach. Allele frequencies were significantly different between all four population groups at three markers (D8S1179, D2S1338 and D2S441) after a Bonferroni correction (ρ < 0.001) and sixteen novel alleles were observed. Two genetic anomalies were observed, namely triallelic patterns at the TPOX marker (n = 9) and a null allele at amelogenin (n = 1). While the sample size for the Indian/Asian population group was limited in this study, the data generated here nevertheless prospects to contribute towards the data currently published for South Africa. This, in turn, will allow for more DNA markers to be analysed during forensic casework in South Africa, as the data for its statistical interpretation is now available.
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Firearm fatalities examined at Salt River Medico-Legal Laboratory in 2009 and their investigative outcome by 2014Wichers, Ansie January 2016 (has links)
South Africa has a very long history of gun violence, particularly politically motivated. The politically motivated gun violence did subside after 1994, however there was an increase in criminal gun violence. In 2004 Dr Liebenberg from the University of Cape Town conducted a study on the victimology and investigative outcomes of firearm deaths of 1999 in the Salt River Medico - Legal Laboratory drainage area. There were some compelling results, including a remarkably low conviction rate of 7.21%. In 2000 new legislation was enacted, which is the Firearms Control Act (1) of 2000 and from 2001 to 2005 there was a 13.6% decrease in firearm homicides which was consistent after the introduction of the new act, likely due to the decrease in the number of firearms in circulation. Because of the changes in firearm legislation and reported crime rates, it was decided to conduct a follow - up study one decade later, looking at the investigative outcomes of firearm deaths to see whether the decreased contribution of firearms in homicides and crime made an impact on the investigative and judicial process of the Salt River Medico - Legal Laboratory cases. In 2009 there were 281 firearm deaths investigated at Salt River Medico - Legal Laboratory as opposed to 532 in 1999. In 1999, 89.29% of firearm deaths were due to homicide as opposed to 86.12% in 2009. In 1999 the majority of firearm homicide victims were Black and Coloured males between the ages of 21 and 30 years, this is similar to what is seen in 2009, however there were fewer Coloured victims in 2009. In both years homicides occurred more often on weekends, at night time. In 1999 there were peaks in May and then from October through to December. In 2009 however, the peaks were in March, May and August. One might thin k that with such a large decrease in the number of firearm deaths (not considering other crime trends), the criminal justice system might have fewer cases to investigate and prosecute and that the investigative outcomes (particularly conviction rate) of th ese cases might improve. Even though there was a significant drop in the number of firearm deaths in 2009, there has been no improvement in the conviction rate, with 2009 having a rate of 5.69%. The number of cases still being investigated was also similar at 104 cases (37.01%) for 2009 versus 182 cases (34.54%) for 1999. In 2009 only 58 (20.64%) cases completed the judicial process by 2014, which includes the 16 cases (5.69%) that ended in a guilty verdict, 18 (6.41%) cases where a suspect was acquitted (not guilty) and also 24 (8.54%) cases that were withdrawn in court. Of the 281 cases for 2009, 10 (3.56%) were still in court, which was significantly less than the 59 (11.20%) cases in 1999. From 2009 there were 87 cases that reached an impasse (30.96%) by 2014, as opposed to the 114 (21.63%) cases from 1999 by 2004, which is a statistically significant difference.
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The validation of forensic DNA extraction systems to utilize soil contaminated biological evidenceKasu, Mohaimin January 2013 (has links)
Includes abstract.
Includes bibliographical references.
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Entomological examination of the relationship between ante-mortem and post-mortem amitriptyline concentrations in insectsSanyanga, Taremekedzwa January 2016 (has links)
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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The analysis of the artefacts produced by forensically significant blowfly (Diptera: Calliphoridae) activity and their effect on bloodstain pattern analysisLesaoana, Mpasi Pascalis January 2016 (has links)
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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The prevalence of infection related death at Salt River Mortuary for the years 2013 and 2014Kruger, Maria Magdalena January 2017 (has links)
Infection related death is of major concern world-wide. This is especially true in developing countries where there is a high burden of disease. In some cases infections may present atypically and death occurs without a diagnosis in life. Many countries, including South Africa, classify these deaths as sudden unexpected or unexplained, which, under the Inquests Acts, necessitates a medico-legal autopsy. In order to understand the mechanisms underlying such deaths, a systematic review of the literature was undertaken on sudden death due to infection. Data from published research and reports identified many pathogens associated with sudden or unexplained death in infants and older individuals. However it remains important to understand locally relevant pathogens. In addition, many risk factors have been identified in different age groups but it is not known what risk factors are prevalent in a local setting and if these correspond to international trends. In order to contribute to local data a case file review was undertaken of infection related deaths at Salt River Mortuary between 1 January 2013 and 31 December 2014 (n=809). Deaths due to respiratory infections were the leading cause of death across all ages and in both sexes. It is not known to what degree this is a true reflection of the cause of death as the extent of autopsy, ancillary investigations and availability of ante-mortem clinical information varied widely. There has been a call for standardised protocols for the post-mortem investigation of these deaths and the data analysed reiterated this need. Many of the modifiable risk factors for infant death identified in the literature review were also identified in the Western Cape Metropole area, with the exception of sleeping position: side sleeping, as opposed to prone sleeping, was identified as the distinctive risk factor. In older individuals tuberculosis was identified as either the cause of death or a major contributor to comorbid conditions, which highlights the importance of further surveillance of vulnerable individuals. These data have provided insight into the extent of infection related death and associated risk factors in a local context. A standardised protocol for the investigation of these deaths across mortuaries would enable more accurate data to be collected which in turn could be fed back into the healthcare system.
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