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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 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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DNA barcoding of forensically important flies in the Western CapeCooke, Tenielle Monique January 2016 (has links)
One of the central applications of forensic entomology is the determination of the post mortem interval (PMI) from arthropod evidence associated with a corpse. Estimations of the PMI are based on succession and developmental patterns of specific species that visit the body. As first colonisers, Calliphoridae (blow flies) are often used by forensic entomologists to determine the PMI however, developmental rates of visiting fauna differ substantially which makes correct species identification vital. Traditional methods of identification which assign species based on keys that capitalise on morphological differences are insufficient for closely related species, especially during immature stages of the lifecycle or when the specimen is damaged. Molecular identification such as DNA barcoding has therefore become a popular method of identifying species. DNA barcoding characterises species by sequencing and analysing specific regions in the genome. This technique has been used to characterise species in various countries including parts of South Africa. Its application has also been demonstrated in a forensic setting but data for the Western Cape is minimal. This study therefore aimed to assess the utility of DNA barcoding for species level determination of four blow fly species common to the Western Cape of South Africa (Chrysomya chloropyga, Chrysomya albiceps, Chrysomya marginalis, and Lucilia sericata) as well as its ability to identify immature specimens. Ten adult specimens from each species were morphologically and molecularly identified using microscopy and DNA barcoding respectively. The standard DNA barcode, cytochrome c oxidase subunit I (COI) and a secondary marker, the second internal transcribed spacer (ITS2) were analysed. Phylogenetic analyses for both barcodes showed high interspecific divergence values which are desirable for species level differentiation by DNA barcoding. COI sequences from adult flies were also submitted and searched against BOLD for identification and only genus level identity could be achieved, indicating that, COI alone may be insufficient to discriminate between closely related species. DNA sequences from the adult specimens were then used as reference sequences for identification of seven unknown immature specimen using DNA barcoding of both COI and ITS2. Sequence similarity was assessed and identity was assigned based on >98% similarity scores, and all immatures were successfully identified. The use of more than one DNA marker to complement morphological data ensures higher confidence of species level identification. This method provides a reliable and consistent tool for entomologists to use for species identification which results in higher levels of accuracy in PMI estimations.
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Retrospective analysis of blunt force trauma associated with fatal road traffic accidents in Cape Town (South Africa) over a two-year periodMajero, T A Tiffany 12 February 2019 (has links)
Road transportation systems are a global developmental achievement. However, with them comes increased morbidity and mortality rates in the form of road traffic accidents. In South Africa, there is a need to characterize road traffic accidents and the injuries associated with them, to determine the preventative mechanisms required to reduce their morbidity and mortality rates. A brief review of fatal road traffic accidents from a global perspective is presented, highlighting the current literature surrounding the prevalence, demographics and blunt force trauma injuries associated with road traffic accidents in South Africa. There is limited research regarding the prevalence and characteristics of road traffic accidents. The objective of this study was to determine the prevalence of fatal road traffic accidents, necessitating the need for research, particularly at the regional level. A retrospective analysis was therefore conducted of all fatal road traffic accident related deaths autopsied at Salt River Mortuary (which services the West Metropole region of Cape Town, South Africa) from January 1st , 2013 to December 31st , 2014. The mean prevalence of road traffic accidents for the reviewed period was 15.9 / 100 000 population. The majority of road traffic accident victims were males who fell in the age group of 30 – 49 years. Over the two-year period, the majority of road traffic accident victims were pedestrians with elevated blood alcohol concentration levels. The head and facial regions of victims commonly exhibited external injuries, while the majority of fractures and organ injury were seen in the head and chest regions. There are limited studies which have investigated the blunt force trauma injuries associated with road traffic accidents in South Africa, and there is a need for further research. Interventions are of paramount importance to decrease fatal road traffic accidents, particularly amongst pedestrians as a road user. This study presents recent data on road traffic accidents for the West Metropole region of Cape Town (South Africa).
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Investigating the impact of Sexual Assault Evidence Collection Kits (SAECKs) as evidence in rape cases prosecuted in the Western Cape High Court between 2012 and 2016Malema, Smangele Benedictor 19 November 2020 (has links)
Background: The Republic of South Africa (RSA) is facing a rape crisis, with women and children being the most vulnerable. DNA evidence is used to aid in suspect identification and to confirm sexual contact. The collection of biological forensic evidence after a rape incident is routine in RSA, however, its contribution to the outcome of rape cases is still unclear. This study aimed to investigate the use of Sexual Assault Evidence Collection Kits (SAECKs) and their impact on the outcome of rape cases. Methods: Data for this study was collected by conducting a retrospective review of rape cases (n=98) prosecuted and finalised at the Western Cape High Court between 1st January 2012 and 31st December 2016. Court dockets were examined, and data was collected using a set of predefined variables. Backward logistic regression was used to analyse whether there is an association between the accused being found guilty and the use of SAECKs and the presentation of DNA evidence. Main findings: In 61% (n=60/98) of the cases a SAECK was used during the medical examination and a DNA report was generated and available for use in 77% (n=46/60) of these cases. There was a higher conviction rate when a SAECK was used (88%, n=53/60) in comparison to when it was not used (53%, n=8/15). Contrary to our expectation, the use of SAECKs was not found to be positively associated with the conviction when using backward logistic regression. This means the use of a SAECK decreased the odds of finding the defendant guilty of rape, albeit by a small degree (OR=0.196, p-value=0.040). DNA was not associated with the case outcome. The majority of cases were stranger rapes (64%,n=63/98), that occurred outdoors (64%,n=61/95)and mostly in the township locations such as Khayelitsha, Philippi, Nyanga, areas located on the Cape Flats, with only a single perpetrator. Injuries were documented in 50% of the cases (n=49)and almost 48% (n=46/95) of the victims were coerced and threatened with a weapon. Our binary model found only the location of incidence (p-value= 0.006) to be significantly associated with case outcome with an odds ratio of 19.827. Conclusions: The findings from this study are significant as they point out that health care practitioners are adequately trained and equipped to provide quality health care responses and to work effectively with police officers. SAECKs are utilised routinely during rape investigations. However, there are various factors relating to the victim, perpetrator and assault characteristics that influence the judge's verdict. This study raised questions relating to how those factors are measured or weighed and are predictive of case outcome. Although we found no positive associations between the variables investigated (except the location of the incident) and court outcome, future research, including larger sample size, should investigate these variables in order to obtain true significance, especially concerning the use of SAECKs and its impact on the court outcome.
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The influence of Methylphenidate on the development of the forensically significant blow fly Chrysomya chloropyga (Diptera: Calliphoridae) in the Western Cape ProvinceVisser, Hartwig January 2016 (has links)
Forensic entomologists rely on insect development and successional data to estimate the post-mortem interval (PMI). Ante-mortem drug use prior to an individual's death may result in drug transmission to feeding insects and subsequent alteration of their development, thereby altering PMI estimates. This study investigated the influence of Ritalin (methylphenidate hydrochloride) (MPH) on the development of Chrysomya chloropyga. C. chloropyga larvae were reared on pig liver treated with MPH and exhibited a trend of expedited larval development and prolonged pupal development. Conservatively, the results suggest that MPH may expedite the larval stage by up to 17 hours and prolong the pupal stage by up to 16 hours. These preliminary findings suggest that, at the concentration investigated, MPH may alter the duration of C. chloropyga developmental stages, and consequently PMI estimates if MPH is not detected or its effects not considered. Furthermore, MPH was detected in both frozen and ethanol preserved specimens. MPH could still be detected from treated larvae, after 3.5 days incubation at ~30°C. This may suggest an improved stability of MPH in insects. Moreover, detection of MPH from ethanol preserved specimens suggests the qualitative toxicological utility of specimens maintained in this preservation liquid, despite stability and self-extraction concerns. These are the first entomotoxicological data on MPH generated for blow flies local to the Western Cape, South Africa.
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