Browsing by Author "Heyns, Marise"

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    A pilot study on stature estimation of the South African male population using the post mortem Lodox® Xmplar-dr imaging device at the Salt River Forensic Medico-Legal Laboratory
    (2022) Venketsamy, Yomika; Heyns, Marise; Mole, Calvin; Dinkele, Elizabeth
    Identification of deceased individuals is of paramount importance in the South African constitution, with victim identification noted as a human right. Stature has been used to assist identification of an individual when skeletal remains are recovered. The usefulness of stature estimation using conventional x-rays, magnetic resonance imaging (MRI) and computed tomography (CT) measurements of long bones in a modern population has been researched in a number of countries, however, there has been limited research conducted on Lodox® bone scans as an added tool for stature estimation in the South African population. Forty-nine deceased males aged 21 to 61 years were scanned with Lodox® within 24 hours of entering Salt River Mortuary for a scheduled autopsy. Total stature was initially measured on the autopsy table with an embedded ruler. The body underwent a full body digital x-ray using the Lodox® Xmplar DR device. To measure length of bones on the Lodox® scans, full body images were exported in DICOM (Digital Imaging and Communication in Medicine) format and five long bone maximum lengths i.e. humerus, radius, ulna, femur and tibia of the bodies were digitally measured using the integrated Lodox® software. Lodox® image scan measurements found that the humerus, femur and tibia were the most statistically significant correlators of stature, individually. The univariate linear regression showed strong statistical significance for the humerus, femur and tibia with estimating stature. Multiple linear regression with the combination of humerus and ulna; femur and tibia; humerus, femur and tibia were statistically significant in determining stature. However, a combination of ulna and radius and the combination of all five bones overall regression was not statistically significant. Univariate and multiple linear regression formulas were created for the South African male population using Lodox® image scan measurements. Correlation and paired t-tests showed significant correlation between manual stature measurement at the mortuary and Lodox® measurements for stature.
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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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    The assessment of the utility and impact of sexual assault evidence collection kits (SAECKS) as DNA evidence in suspected cases of rape
    (2014) Cupido, Danielle; Heyns, Marise
    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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    Confirmation of cardiomegaly from the cardiothoracic ratio post-mortem Lodox® imaging
    (2018) Hofler, Rosemarie Ursula; Heyns, Marise; Liebenberg, Linda
    In post-mortem forensic radiology the cardiothoracic ratio (CTR) is seen as the most reliable and easiest method for the detection of an enlarged heart, where the maximum transverse diameter of the heart is divided by the maximum transverse diameter of the internal thoracic cage and if the result is greater than or equal to the 50 % threshold, the heart is deemed to be enlarged. This threshold is widely accepted and used in both clinical practice and in medicolegal post-mortem investigations. The primary aim of the study was to investigate the accuracy and reliability of this CTR threshold measured from the radiographs produced specifically by the Lodox Xmplar-dr scanner situated at the Forensic Pathology Service (FPS) Laboratory in Salt River, Cape Town, Western Cape. A secondary aim was to typify the observed enlarged heart, whether it was due to ventricle dilation or ventricle wall thickening leading to a diagnosis of cardiomegaly. The study was divided into a retrospective component which investigated past use of the CTR (%) in autopsy reports with regards to the cause of death/chief findings, at the Salt River FPS laboratory using the Division of Forensic Medicine and Toxicology, UCT, Office autopsies database, between years 2014 to 2016. The prospective component evaluated the reliability and accuracy of the CTR measured from conventional radiography produced by the Lodox scanner by comparing the diagnosis obtained from the CTR calculated from the Lodox images with the recorded heart weights. This CTR was also then compared to the CTR calculated with the heart in-situ in the pericardial sac to determine how accurate the radiograph produced from the Lodox scanner is for diagnosing an enlarged heart. The results showed a significant difference between the CTR calculated from the Lodox images versus the CTR calculated from the in-situ measurements, with the CTR from the Lodox images being better at detecting enlarged hearts, at 76 %, whereas the CTR calculated in-situ was better for detecting normal heart weights, at 84 %. Increasing the 50 % threshold would increase the specificity, thereby increasing the number of correctly identified normal heart weights as well as enlarged hearts, therefore a CTR threshold of 52 % (0.52) is recommended for the Lodox scanner for diagnosing an enlarged heart. When typifying the observed enlarged hearts the lack of mid-ventricular wall thickening together with the wall thinning suggests that the main cause of the CTR being over it 50 % threshold is dilation. It is important to note that in some of the cases the heart weight was still within the normal heart weight range.
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    The contribution of respiratory pathogens to Sudden Unexpected Death in Infancy
    (2016) Ishimirwe, Elyse Sandrine; Kaba, Mamadou; Heyns, Marise
    Background: Sudden unexpected death in infancy (SUDI) is among the most frequent causes of mortality in infants less than one year of age. Respiratory infections have been identified as the most frequent cause of death in these infants. Yet, the broad range of respiratory pathogen that might be involved in SUDI is poorly studied. This study aimed to investigate the incidence of the respiratory pathogens in SUDI. Methods: A prospective study was carried out on SUDI cases admitted to Salt River Forensic Pathology Laboratory from February 2015 through May 2015. Cerebrospinal fluid, pericardial fluid and lung biopsy were collected from each study participant during post-mortem examination. Total nucleic acids were extracted on the automated QIAsymphony platform. The microbial diversity was investigated using a commercialized multiplex real-time PCR assay, the "FTD Respiratory pathogens 33" kit. This assay is able to detect 21 viruses, 11 bacteria and one fungus. In each real-time PCR run, a positive and non-template sterile water were included as controls. Results: Thirty SUDI cases (median age, 3 (interquartile range (IQR): 2 - 8 months) were included in the study. Twenty participants were males. Positive microbiological results from at least one of the three samples were obtained in 28 cases (93%). According to the type of sample, respiratory pathogens were detected in almost all the lung biopsies (93%), while it was only detected in 60% and 50% of the cerebrospinal and the pericardial fluids, respectively. The median cycle threshold value was lower in lung biopsies (30 (IQR: 28 ‒ 35)) compared to both cerebrospinal (34 (IQR: 30 ‒ 36)) and pericardial fluids (35 (IQR: 33 ‒ 35)) (p= 0.039). In lung biopsies, the most commonly detected bacteria were K. pneumoniae (47%, 14/30) and M. catarrhalis (20%, 6/30). H. influenza (7%, 2/30) and M. pneumoniae (7%, 2/30) were the bacteria often detected in pericardial fluid and cerebrospinal fluid, respectively. Human Metapneumovirus was the most frequently virus detected in all three sample types assessed, accounting for 33% (10/30) in cerebrospinal fluid, 37% (11 /30) in pericardial fluid and 57% (17/30) in lung biopsy samples, respectively. A single type of pathogen was detected n seven of the 28 positive cases. Conclusion: This study highlights the potential implication of respiratory infection in SUDI and it reports one of the highest incidences of respiratory pathogens in SUDI cases. In addition, it is the first to report the high incidence rate of Human Metapneumovirus in SUDI cases. The findings also showed that the majority of SUDI cases are associated with synergetic interaction of multiple respiratory infections. However, data related to histopathology and bacterial culture were not available. A broad range of respiratory pathogens should be included in the routine investigation of SUDI cases with more sensitive diagnostic methods.
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    Development of a method for the screening and quantification of methamphetamine, and its major metabolite amphetamine, in hair using liquid chromatography-tandem mass spectrometry
    (2015) Johnston, Jenna; Smith, Peter; Heyns, Marise
    Hair has, over recent years, become widely recognised as an alternate or complementary matrix to blood and urine for drug analysis. Hair analysis offers a wider detection window after drug exposure than blood or urine testing and can provide a long-term history of an individual’s drug use. There are several practical applications of hair analysis for drugs including workplace drug testing, doping control, driving licence re-granting, drug-related deaths and drug-facilitated crimes. As a result hair analysis is currently being performed within various toxicological fields in laboratories around the world. However, before the start of this study no hair analysis for drugs was being performed in South Africa. Therefore, the main aim of this study, as stated in Chapter 1, was to develop a method for the detection and quantification of drugs of abuse, specifically methamphetamine and amphetamine, in hair using High Performance Liquid Chromatography coupled to Mass Spectrometry.
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    DNA barcoding of forensically important blow flies (Diptera: Calliphoridae) within the Western Cape of South Africa
    (2019) Kulenkampff, Kyle Sieghard; Heathfield, Laura; Heyns, Marise
    In forensic entomology, determining species identity is a crucial step towards estimating post mortem interval. DNA barcoding can aid in the identification of unknown forensically relevant species, and this requires the comparison of DNA barcodes to reference data from known species. However, there is a lack of DNA barcode reference data of forensically relevant Calliphoridae species in the Western Cape (South Africa). DNA barcodes were generated for the COI and ITS2 markers for 41 forensically relevant Calliphoridae specimens, representing seven species from six localities in the Western Cape: Chrysomya albiceps (n = 3), Chrysomya chloropyga (n = 8), Chrysomya marginalis (n = 5), Chrysomya megacephala (n = 7), Hemipyrellia fernandica (n = 1), Lucilia cuprina (n = 8) and Lucilia sericata (n = 9). This data was combined with that from Cooke et al. (2018) (n = 40), and subjected to rigorous statistical and phylogenetic analyses. Phylogenetic analysis which combined data for both COI and ITS2 barcodes returned monophyletic clades for each species with increased support when compared to using each barcode individually. This combined dataset was able to discriminate between L. cuprina and L. sericata with full support (100% pP), which was not achieved previously. DNA barcodes were evaluated for intra- and inter-specific variance as well as haplotype patterning. No haplotype patterning was observed for either barcodes across sampled localities. Lastly, a single-blinded approach was used to assess the dataset, whereby DNA barcodes from ‘unknown’ specimens were correctly identified using this reference data. These identifications were more accurate than those using GenBank® or BOLD, highlighting the importance of using locally relevant reference data. This study has contributed new data pertaining to DNA barcodes for seven Calliphoridae species, which was previously scarce for the Western Cape, and this has directly contributed to an improvement in the accuracy of local species identification.
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    DNA barcoding of forensically important flies in the Western Cape
    (2016) Cooke, Tenielle Monique; Heyns, Marise; Heathfield, Laura
    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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    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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    Examining external morphological characteristics of Lucilia sericata pupae for age estimation in medico-legal investigations
    (2021) Alberts, Lisa; Mole, Calvin; Heyns, Marise
    Insects play an essential role in the resolution of medico-legal investigations. For various insects, like necrophagous flies, it is vital for their survival to find and inhabit a food source such as a decomposing body. This makes it possible to use these insects as evidence in medico-legal investigations. A crucial part of any medico-legal investigation is estimating the time that has elapsed since death, otherwise known as the post-mortem interval (PMI). The age of the oldest insects can provide the most precise estimation of the PMI. Flies undergo different stages of development. All the immature stages can be utilized as evidence at death scenes. Out of all the immature stages, pupae represent the oldest specimens, which makes them valuable in establishing a minimum time since death. Identification and aging of pupae is currently a challenging process since they all look similar in appearance. Few studies have been done on pupae for PMI estimation. This study aims to identify reliable morphological markers to aid in a more accurate age estimation of Lucilia sericata during the pupal stage. A total of 145 pupae were collected and examined for external morphological changes over time. Five pupae were collected at each time point. A total of six external morphological characteristics of the puparium and twenty external morphological characteristics of the pupae were initially examined. These characteristics were linked to age in accumulated degree hours (ADH), with the aim of creating a timeline that can aid in the estimation of pupal age. The pupal ADH ranges from the youngest being 6550 ADH and the oldest being 11300 ADH. The timelines identified several characteristics that develop during the early or late stages of development. Multiple linear regression analysis was performed to assess characteristics which were useful for estimating the age of the pupae (ADH) and develop a regression equation based on the data collected. The regression analysis identified 10 characteristics that are the most significant in aging pupae. They were the colour and shape of the labellum, leg length, leg width at full length, thoracic setae, facial setae, abdominal macrosetae, palp shape, genal setae and labrum colour. Some of these characteristics like the leg length and width and abdominal macrosetae did provide important time-breaks on their respective timelines. However, the development and the pigmentation of the compound eye also provided valuable time-breaks it's timeline.
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    Firearm fatalities examined at Salt River Medico-Legal Laboratory in 2009 and their investigative outcome by 2014
    (2016) Wichers, Ansie; Liebenberg, Linda; Heyns, Marise
    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 influence of Methylphenidate on the development of the forensically significant blow fly Chrysomya chloropyga (Diptera: Calliphoridae) in the Western Cape Province
    (2016) Visser, Hartwig; Heyns, Marise; Davies, Bronwen
    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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    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 2016
    (2020) Malema, Smangele Benedictor; Heyns, Marise; Molefe Itumeleng
    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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    Investigation of blunt injuries and the force associated with a skull fracture due to impact with a Hopkinson pressure bar : an animal model
    (2015) Coetzé, Lisa Jane; Heyns, Marise
    Homicide is one of the leading causes of death in South Africa. Homicides as a result of a firearm, sharp instrument or blunt object, may all potentially inflict severe cranial trauma. Often the lateral aspect of the cranium is fractured in homicidal assaults, however, the focus of head injury biomechanics has been the frontal bone. This is due to automotive-related incidents. Thus it is important for researchers to broaden their knowledge on lateral head impacts. This data could ultimately act as a tool in making cranial bone trauma analysis less subjective in nature. This minor dissertation discusses human cranial bones and explores different types of cranial fractures. It further provides an in depth discussion on the different types of experimental tests and specimens used in biomechanical testing. A current review on the literature surrounding head impacts is also provided. The research conducted for this minor dissertation uses the Cape (Chacma) Baboon as a model to attempt to simulate cranial blunt trauma observed in human bone. Fifteen Cape (Chacma) Baboon head specimens were subjected to a single temporo-parietal impact. These specimens were impacted with an aluminium striker bar that resembles the dimensions of a hammer (length: 23cm, circumference: 40cm and weight: 200g). The aim of these hammer tests were to characterise soft and hard tissue wound morphology as a result of blunt cranial impacts. Resulting data was analysed to determine if a significant correlation existed between impact velocity or energy and the extent of trauma observed. The remaining twelve Cape (Chacma) Baboon specimens were all subjected to a single impact in the temporo-parietal region. These specimens were impacted with a Hopkinson pressure bar, which is manufactured from the same material as the striker bar. The aim of the Hopkinson pressure bar tests was to attempt to determine the force of impact. The use of the Hopkinson pressure bar to determine fracture forces in baboon head specimens is novel. The fracture forces obtained in the current study compare well with literature investigating lateral impacts. Furthermore, the fracture patterns obtained in the current study realistically simulate cranial trauma seen in humans. It would therefore be beneficial to advance research using the baboon model and Hopkinson pressure bar apparatus.
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    Patterns of blunt force homicide in the West Metropole of the City of Cape Town, South Africa
    (2017) Clark, Courtnee; Mole, Calvin G; Heyns, Marise
    There is currently a lack of information regarding the prevalence of 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 development and implementation of interventions targeted at specific areas or individuals as well as direct future research towards areas in need of investigation. This study is a 5-year retrospective review of autopsy reports obtained from Salt River Mortuary (Cape Town, South Africa). The prevalence of blunt force trauma was considered for unnatural deaths with a focus on homicide. The patterns of homicidal blunt force trauma are also presented. A total of 15 519 autopsy cases was analysed. In 1198 (7.72%) of these cases, the cause of death was found to be blunt force trauma and 828 (5.32%) of these cases were classified as homicides. Approximately 11% of blunt force homicide cases occurred in combination with sharp and/or ballistic trauma. Men from poor socio-economic areas were shown to be most at risk of blunt force homicide in the City of Cape Town.
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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.
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    Pilot study : Investigating the chemical composition of illegal drugs and the associated prevalence of the different drug types in the Bellville and Athlone police districts in the Western Cape, South Africa
    (2016) Westraat, Hendrik; Heyns, Marise
    Very little chemical information is known about substances being abused in South-Africa. This can be attributed to the fact that possession of drugs constitutes a criminal offence. Not much research is done, and with the exception of self-reported, rehabilitation institution data, from the South African Community Epidemiology Network on Drug Use (SACENDU) and the South African Police drug related arrest data, no other data on drugs and drug use, is publically available. Drugs are being manufactured from legal and illegal chemicals in clandestine laboratories, not complying with any health, safety or quality standards causing a serious health risk in communities. The strategy for the fight against drug abuse in South Africa, the National Drug Master Plan 2013-2017 (NDMP), is compiled by the Central Drug Authority (CDA). Without proper research, data to base decisions and strategies on and proper measuring of achievements, the implementation of the plan suffers as a consequence. The Forensic Science Laboratory (FSL) of the South African Police Service (SAPS), is responsible for the chemical testing of substances, suspected of being illegal drugs, for identification purposes. This supports the prosecuting of suspects during criminal procedures. With the active ingredient known, the use of street names e.g. Tik, Choef or Speed (all referring to methamphetamine) can be abandoned and confusion and misconceptions eliminated. This pilot study investigates the arrest data, in combination with the charge laid against the arrestee and the chemically identified active ingredient in each case. Arrest data revealed a 400% increase in drug related arrests over the last 10 years, while the NDMP requires a 10% decrease. It further highlights the fact that the measurement of success (number of arrests) in the SAPS, resulted in a focus on arresting persons in possession of drugs. The dealers and manufacturers were not adequately addressed and prevention, through chemical monitoring, suffered as a result. This study also clearly revealed that international trends are not a definite indication of the extent and type of drug abuse in South African Communities. The study further attempts to contribute, and to better describe the situation of drugs and drug abuse in communities. This in turn, will provide data to develop evidence based strategies, designed to meet the defined needs of communities, one of the aspects highlighted by the minister in the NDMP, namely an intervention based on reality and local statistics. It is therefore clear that a scientific understanding of the composition of abused substances can direct treatment, policy, prevention measures and provide intelligence to combat drug abuse and illegal drug manufacturing in South Africa.
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    Retrospective review of gunshot injuries at Salt River mortuary, Cape Town, Western Cape
    (2023) Ramonyai, Jonathan; Heyns, Marise; Dicks Herman
    The use of firearms to inflict fatal trauma is a social, economic, and public health concern globally. In South Africa, firearm-related injuries (FRIs) have become the leading cause of unnatural death. Despite this, few studies have investigated the demographic, geographic and temporal distribution of firearm-related fatalities in South Africa. The aim of this study was to investigate fatal firearm-related injuries in forensic cases admitted to Salt River Mortuary in Cape Town, South Africa. A retrospective crosssectional study of fatal FRIs from Salt River Mortuary was conducted for the period 1 January 2017 to 31 December 2017. Autopsy case files were screened for fatalities associated with firearms. The following data were obtained from the database: demographics of the deceased, geographic and temporal distributions of firearmrelated deaths, the type of firearm used, projectile calibre, size of the entrance and exit wound, location of the injury, and blood alcohol concentration (BAC) of the deceased. In 2017, 3 658 autopsies were conducted at Salt River Mortuary in Cape Town, South Africa. More men (75%, n= 2 743) were admitted than women (23%, n= 843). The rate of firearm-related deaths during the period of investigation was 39.8/100 000 population of Salt River. Men (95%, n= 732) were mostly affected by firearm-related injuries compared to women (5%, n= 40). The relative risk of firearm-related deaths among men was 5.62 (p<0.001. Firearm-related homicide (97%, n= 751) was common and suicide cases were rare (2%, n= 19). All age groups were affected however, the highest proportion of deaths was identified in those between 21-30 years of age (42%, n= 325). Most deaths occurred in the Cape Flats with Mitchells Plain (18%, n= 108) as the most affected region. The highest proportion of injuries occurred in the upper limbs of the body (23%, n= 1056) followed by the head (22%, n= 1013). This study adds to the growing body of literature on the prevalence and characteristics of firearm-related deaths in South Africa. Firearm violence still appears to be a major public health and safety concern in Cape Town and further interventions should be developed to curb gun violence.
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    The use of histological examination methods to distinguish between the burnt remains of human and non-human bones
    (University of Cape Town, 2020) Labuschagne, Lizl; Mole, Calvin; Heyns, Marise
    Distinguishing between burnt human and non-human bone fragments using macroscopic methods has proved challenging and it was seen in the literature review that the previous research did not all come to the same conclusions. The aim of the research was to determine if, using histological methods, it was possible to distinguish between burned human and nonhuman bone fragments. A literature review was compiled to provide an overview of the anatomy of bones, morphological characteristics of bone, general bone histology, a comparison between human and non-human bones and the effect of temperature on bones. Bones of five different species (human, baboon, wildebeest, pig and cow) were burned in a muffle furnace for twenty minutes at either 600áµ’C or 800áµ’C. Following the burning procedure, thin ground bone sections of the burned and unburned bone specimens were prepared for microscopic analysis and the minimum canal diameter, maximum canal diameter, minimum Haversian system diameter, maximum Haversian system diameter, area of canal, and area of the Haversian system were measured. A comparative analysis was then done across species and temperature. A total of 523 osteons in unburned bone and 147 in the burned bone samples were analysed. ANOVA testing found overall significance (p < 0.0001) for all parameters measured, which suggests that temperature does affect the size of microstructures. Most parameter sizes increased with an increase in temperature. A greater increase was seen at 600 degrees than 800 degrees. Qualitatively, carbonation within the burned bone, made the measurement of parameters difficult in some samples. Human bone can easily be differentiated from pig, cow or wildebeest bone due to no or very few osteons present. Pig bone consisted almost entirely of plexiform bone, while the cow and wildebeest presented with only a few osteons in some parts of the bone. Human and baboon bone appeared similar on a microscopic level. The study revealed that temperature did not, in general, hamper the ability to differentiate between burned human and non-human bone, but it did impact on the number of measurable data points for each parameter.
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    Understanding the mechanism of injury associated with long bone fractures through dynamic bending impact
    (2019) Emrith, Toshika Sheshna; Mole, Calvin; Heyns, Marise
    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.