Browsing by Author "Mole, Calvin"

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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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    A retrospective analysis of post-mortem procedures of sudden unexpected death in the young investigated at Salt River Forensic Pathology Services, Cape Town
    (2022) Hamadziripi, Dirk M; Heathfield, Laura; Mole, Calvin
    Sudden unexpected death in the young (SUDY) is the demise of a seemingly healthy individual aged between one and 40 years. The scope of SUDY investigation varies and there is little research regarding SUDY at Salt River Mortuary (SRM). Accordingly, the objectives of this study were to determine the number of SUDY cases admitted to SRM, document the scope of investigations, and identify candidates for retrospective molecular autopsies. A total of 1088 cases were admitted between 1 January 2010 and 31 December 2015, representing 3.3% (1088/32812) of the entire case load, 30 were excluded as the files were missing. Full autopsies (56.7%; 600/1058) were preferred to partial autopsies (5.6%; 59/1058) and external autopsies (37.7%; 399/1058). The most utilised ancillary tests were LODOX imaging (86.6%, 916/1058) and toxicology (34.8%; 368/1058). Specificity of cause of death was seen to be significantly associated with the extent of autopsy. A total of 35.7% (378/1058) of the cases were established as candidates for molecular autopsy on the criteria of being undetermined, having unspecific causes of death or having specific causes of death that are deemed hereditary. Findings of this study show that SUDY cases do not always undergo all ancillary tests coupled with retention of biological samples. These findings provide insight into the current gaps in the investigation of SUDY cases at SRM and highlight areas for improvement.
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    A retrospective descriptive analysis of fatal ground level falls and falls from a height: A 5-year review
    (2022) Chonyera, Rumbidzai Lorraine Stephanie; Mole, Calvin
    Falls have been identified as the second leading cause of accidental deaths in the world and has become a public health issue. Depending on the manner and height at which the fall occurs, different injury patterns are observed, and these are useful for the determination of circumstances surrounding death. The aim of the present study was to determine the demographic characteristics, prevalence and injury patterns associated with ground level falls and falls from a height. A five-year (1 January 2014 - 31 December 2018) retrospective descriptive review of fatal fall cases investigated at Salt River mortuary was conducted. The prevalence and patterns of injuries were assessed with regard to fall height, impacting surface and victim demographics. There were 360 fall related deaths. Fall prevalence in the Western Metropole District of Cape Town is 3.72/ 100 000 population. Ground level falls were prevalent among the elderly while younger individuals fell from greater heights. There is an association between the sex of an individual and height from which they fall. Accidental falls were more common and no association was found between the alleged manner of death and sex. Skeletally, a higher frequency of fractures was observed in ground level falls while the head, chest and pelvis were affected in the high level falls. additionally, an association was observed between injuries sustained and fall heights. There is a significant difference in fracture proportions between the heights in the pelvic and lower extremities and no significant difference in head, spine, chest and upper extremities. As expected, trauma associated with falls varies based on the height of the fall. Lower extremity fractures are common in ground level falls however a challenge remains for falls from a height as there is a need for more studies to focus on the diverse patterns that occur in these.
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    A retrospective study investigating risk factors for sudden unexpected death in the young
    (2022) Oghenechovwen, Ogheneochuko Mary; Heathfield, Laura J; Mole, Calvin
    Sudden unexpected death in the young (SUDY) is the unanticipated demise of individuals aged between 1 and 40 years. In South Africa, these deaths are referred for forensic investigation. The primary aim of this study was to retrospectively investigate the frequency of known risk factors in SUDY cases admitted to Salt River Mortuary in Cape Town and explore differences between males and females. There were 1 088 SUDY cases identified with 0.9% (10/1 088) missing files. Reviewed cases were n=1 078, 62.6% (675/1 078) males, and 37.4% (403/1 078) females; 83.5% (901/1 078) adults and 16.4% (177/1 078) children, accounting for 5.6% of total admissions between 1 January 2010 and 31 December 2015. Despite the predominance of males, significantly more females (61.8%) were obese (p < 0.05). At least one primary medical condition was present in 53.7% of cases, with the leading conditions being tuberculosis (11.9 % of adult males), epilepsy (11.7% of adult males; 10.3% of female children), HIV (10.7% of adult females) and asthma (11.1% of male children). In the subset of the study population where information was available, before death, 74% of individuals were reported to have experienced prodromal symptoms; 37.6% of males and 32.4% of females did not seek medical intervention following symptoms. Information regarding a family history of sudden death was known in 237/1078 cases. In 3.2% of these cases, a family history of sudden death was reported. Significantly more males than females reported the use of tobacco, alcohol, and other illicit drugs (p < 0.05). More females were unemployed (p < 0.05). Interventions based on lifestyle modification, social support, pharmacologic needs, and awareness should be targeted at individuals with the above profiles, especially those with a family history of sudden death, as they may be high-risk groups. Findings from this study contribute new and relevant local reference data for SUDY risk profiles of males and females admitted to Salt River Mortuary.
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    Adult age-at-death estimation using the pulp/tooth area ratio (PAR) method: a South African validation study using periapical radiography and stereomicroscopy
    (2024) Kotze, Daniël; Gibbon, Victoria; Mole, Calvin
    Conventional skeletal age-at-death estimation methods employed for South African adults are deficient, facing several limitations. Dental ageing techniques remain under-researched for the population. In this study, I aimed to evaluate the applicability of the pulp/tooth area ratio (PAR) ageing method when applied to maxillary canines from a South African cadaveric sample. I explored the utility of under-researched methodological approaches for the method: mesiodistal radiographs, stereomicroscopic tooth section images and PARs excluding the enamel area. To maximise sample size, only maxillary canines were considered, which demonstrate several research advantages (e.g. relatively long functional survival and high accuracy rates). Following extraction, 52 adult teeth were radiographed, sectioned and analysed using stereomicroscopy. Labiolingual and mesiodistal radiographs and labiolingual stereomicroscopic tooth section images were captured and analysed using ImageJ to obtain PARs. Age estimation linear regression models were developed for ratios obtained from each image type, including and excluding the enamel area. Models were compared for performance and accuracy using best subsets regression and cross-validation analyses. The accuracy of international standards was also assessed using the study sample. The PAR method showed promising results. It demonstrated excellent observer reproducibility and sex-independence. Sample-specific models derived from tooth section images had the best performance and accuracy, obtaining cross-validation mean absolute errors (MAEs) and standard error of the estimates (SEEs) of approximately 7 - 8 years and 10 - 11 years, respectively. Labiolingual radiographic models (MAEs = 10 years; SEEs = 12 years) showed better performance and accuracy than mesiodistal radiographic models (MAEs = 12 years; SEEs = 16 2 years). Models excluding the enamel area performed better, producing slightly better cross validation error values. Standard PAR models performed relatively poorly and were inappropriate for the study sample. This research suggests that the PAR method is a suitable technique to complement and inform standard adult skeletal age analyses in South Africa. The labiolingual radiographic approach is most practical as it is relatively accurate, minimally invasive and efficient. This study contributes knowledge to the limited pool of data on dental ageing techniques for South African adults. It informs practitioners of ideal/optimal methodological approaches for the PAR method using maxillary canines.
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    An assessment of electrical deaths in the Western Cape Province from 2011 to 2020
    (2024) Chetty, Ansuya; Mole, Calvin
    Electrical injury is a significant cause of morbidity and mortality worldwide. When an individual comes into contact with an electrical current, the resulting injury can range from minor burns to cardiac arrest and death. Electrical deaths are particularly concerning due to their sudden, unexpected nature, and the fact that they often occur in otherwise healthy individuals. This study aimed to explore the pathophysiology of electrical injury and its effects on regions of the human body. Two sets of data were examined to ascertain the prevalence and patterns of electrical deaths in the Western Cape Province of South Africa between 1 January 2011 and 31 December 2020.The first data set contained the variables of age, date of death, sex, suburb and blood alcohol concentration. The second data set was a retrospective review of autopsy reports from Salt River Mortuary, to provide an in-depth analysis of injury patterns and the circumstances surrounding these deaths. The medicolegal data from the Western Cape Province, South Africa were reviewed and the demographics analysed. A total of 401 cases of fatal electrocutions were identified, where the City of Cape Town was identified as a hotspot, reporting over 64% of these deaths. Males aged 21 to 30 years old were identified to be most vulnerable to electrical deaths. Medicolegal case files were reviewed retrospectively to obtain the demographics, circumstances and electrical sources of the electrocution fatalities at Salt River Mortuary (SRM) in Cape Town. A total of 102 cases were reviewed from SRM, where 370 joule burns were recorded in the electrical deaths. Electrical injury was primarily seen in the extremities and upper regions of the bodies. A variety of injuries were recorded including minor burns, deep burns and charring. The intensity and prevalence of injury was compared between males and females. Vulnerable demographics and prevalent circumstances surrounding electrical deaths were identified. The main electrical sources were live wires from exposure to illegal connections and cable theft. Ultimately, a better understanding of electrical injury can help to improve prevention and management strategies, leading to better outcomes for those affected by this devastating type of injury.
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    Assessing the accuracy of the zygoma for estimating ancestry using geometric morphometrics in a South African sample
    (2019) Tawha, Tafadzwa Primrose Rudo; Gibbon, Victoria E; Dinkele, Elizabeth; Mole, Calvin
    The large number of unidentified, decomposed and skeletonised remains found in South Africa (SA) necessitates relevant and reliable methods to assist in victim identification. Ancestry estimation from unknown skeletal remains is essential when reconstructing a demographic profile of a missing person. In the SA population, estimating ancestry is problematic as standards developed internationally rarely apply to the local, biologically heterogenous population. Craniofacial morphology is known to be ancestrally distinct and studies are yet to explore shape and size variation in the zygomatic bone of the SA population. The aim of this study was to assess ancestral variation in zygomatic shape and size in a SA population using three-dimensional geometric morphometric analyses. A sample of 158 individuals were analysed from Bantu-speaking (BA), European (EA) and Mixed Ancestral (MA) South African groups. Males were larger in size than females, but no size differences were observed between ancestral groups. Significant shape differences were observed between ancestral groups, while none were observed between males and females. BA and MA individuals had narrower, shorter and more anteriorly projecting zygomas than EA individuals. The zygoma was shown to accurately distinguish EA (84%) from BA (81%), and MA (80%) from EA (68%) individuals, but unreliably distinguished BA (60%) from MA (66%) individuals. This is likely correlated to the historical peopling of SA and historical forced racial classification. Age-related changes and antemortem tooth loss did not confound the ancestral variation in size, despite minor changes in zygomatic shape being associated with these two factors. These confounders did not impact ancestry estimation accuracies, further suggesting a minor impact on overall zygomatic shape. Furthermore, the patterning of ancestral variation in the zygoma revealed the need for further research to distinguish between the biologically heterogenous ancestral groups in SA.
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    Evaluating the use of capillary electrophoresis in the forensic DNA profiling of burnt teeth
    (2023) Geldenhuys, Adriaan; Mole, Calvin; Martin Donna-Lee
    Fires are a frequent cause of death, both globally and in South Africa, and often, individuals are burnt beyond the point of visual recognition. Teeth maintain their structure and can withstand high temperatures; making them a possible source of DNA from burnt human remains. DNA profiling is the current gold standard in forensic human identification, however, limited literature pertaining to DNA profiling of burnt teeth exists. The aim of this study was thus to evaluate the success of capillary electrophoresis in the forensic DNA profiling of teeth burnt at different temperatures, using an optimised DNA extraction protocol. Tooth samples from 25 donors (n = 100 [4 teeth per donor]) were subjected to three burning conditions, one tooth was left unburnt to act as a control and three teeth were each burnt in a muffle furnace at 100 ˚C, 200 ˚C, and 300 ˚C. The colour and weight of the teeth were recorded before and after burning. DNA was extracted using an optimised demineralisation step. Extracted DNA was quantified through real-time PCR and profiled using capillary electrophoresis with the Promega PowerPlex® ESX 16 system. Teeth burnt at 100 ˚C resulted in the most full profiles (96 % ; n = 24/25), followed by teeth burnt at 200 ˚C (84 %; n = 21/25), with 16 % partial profiles obtained (n = 4/25). Teeth burnt at 300 ˚C resulted in a large number of failed profiles (88 % ; n = 22/25), and had a significant decrease in profiling success (p = 0.001) and concentration (p = 0.001), and were significantly more degraded (p = 0.001), compared to control samples and samples burnt at lower temperatures. These results suggest that conventional DNA profiling methods and the DNA extraction method used herein are suitable for obtaining full DNA profiles from teeth exposed to temperatures as high as 200 ˚C, however, more sensitive methods such as targeted next generation sequencing (NGS) would be recommended to obtain more insight into highly degraded and fragmented samples, such as those burnt at 300 ˚C.
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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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    Insect succession and changes in the soil pH and electrical conductivity associated with decomposing pig carcasses on the Table Mountain National Park of the Western Cape Province of South Africa
    (2023) Adetimehin, Adeyemi; Mole, Calvin
    The establishment of region-specific baseline data on carrion-associated entomofauna and changes in the chemistry of carrion-impacted soil is crucial in the application of forensic entomology and soil chemistry in post-mortem interval estimations. However, within the Western Cape Province of South Africa, and specifically, the Table Mountain region, no studies on carrion-associated entomofauna have been published. Also, no studies in South Africa have investigated how the changes in carrion-impacted soil chemistry can be used in post-mortem interval estimations. Therefore, to establish baseline carrion entomofauna data, this study investigated the insect assemblages associated with decomposing neonate pig carcasses, alongside the impact of carcass decomposition on soil, carcass skin, and larval mass(es) chemistry, on a monthly temporal scale across the spring, summer, autumn and winter seasons. Secondly, in line with the quest for forensic relevance as evidenced by the observations from local forensic cases within the Province, this study examined the similarity in the collected carrion entomofauna, soil, carcass skin and larval mass(es) chemistry data generated from the neonate pig studies, with those generated from singly deployed adult pig carcasses across the winter and summer seasons. Thirdly, to further establish the forensic relevance of the entomofauna data generated from experimental studies, this study examined the insect species documented in forensic entomological reports of actual forensic cases within the Western Cape Province and compared the data therein with those generated from field studies using neonate and adult pig carcasses. A total of twenty-four neonate pig carcasses (two for each monthly trial) were used to generate baseline data on carrion-associated entomofauna and changes in soil pH and electrical conductivity, carcass skin and larval mass(es) in each month across the spring, summer, autumn, and winter seasons, between August 2020 to September 2021. Similar data were collected over the winter and summer seasons respectively using two adult pig carcasses (one for each seasonal trial) between June 2022 to January 2023. The neonate pig carcasses decomposed twice as fast in the summer season when compared to the spring and autumn seasons, and four times faster than those deployed in the winter season. The adult pig carcass deployed in the summer season decomposed approximately eight times faster than that deployed in the winter season.
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    Investigating the current scope and potential of forensic entomology in decomposition cases at Salt River Mortuary, Cape Town, South Africa
    (2023) Laubscher, Tyrian; Mole, Calvin
    Decomposition cases form a fraction of the medico-legal cases conducted at Salt River Mortuary (SRM). With prolonged time since death and increased decomposition, entomological evidence becomes increasingly important in the estimation of minimum post-mortem interval. Currently no standard protocol exists for the handling of entomological evidence by SRM personnel and there is a lack of information about the issues that may impact the handling of these death scenes and associated entomological evidence. Therefore, this study aimed to investigate the current scope of cases involving entomological evidence at SRM. This was achieved by performing a six-year retrospective review of medico-legal cases performed at SRM from 2015 to 2020, and interviewing SRM personnel to gather data regarding attended scenes, methods and processes used on the scenes, and issues they may have faced. A total of 264 decomposition cases were examined at SRM in the six-year period, with 109 (41.3%) presenting with insect activity. Data about variables such as scene type, weather season, decomposition stage, burial or covering of remains, and open wounds were extracted from the case files. As expected, a greater proportion of cases presented with entomological evidence in the warmer summer and spring seasons compared to the cooler seasons, with no significant difference in the distribution between years (p=0.62). Insect activity was predominantly found in indoor cases, but this is not statistically significant (p=0.50). Most cases presenting with entomology activity were associated with early-stage decomposition. No association was observed between the presence of open wounds and insect activity. The interviews provided data that could not be extracted in the reviews, due to personal experience being provided by personnel. The primary themes emerging from the interviews were related to the insufficient training on the handling of entomological evidence, poor availability of resources for the handling of the entomological evidence, and scene dependent variables that differ between scenes and impacts how a scene is handled. This study identified areas that need improvement and provides a better understanding of entomological activity associated with decomposition cases. There is potential for the greater utility of forensic entomologists in medico-legal cases, and the implementation of a standardised entomological protocol along with proper training of personnel may improve medico-legal investigations of decomposition cases.
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    Investigating the effect of NucleoSpin® Forensic Filters on DNA recovery from swabs
    (2021) Hitewa, Alina Ndahafa; Heathfield, Laura; Gibbon, Andrea; Mole, Calvin
    The burden of unresolved crime in South Africa highlights the need to improve methods of identifying perpetrators of crimes. One globally accepted method for human identification is forensic DNA profiling. Since trace evidence is often retrieved in small amounts, the optimal recovery of DNA from these samples is crucial. Methods for the recovery of touch DNA from swabs typically make use of a spin basket or filter, combined with a centrifugation step, to enhance the release of cells from the swab prior to DNA extraction. The NucleoSpin® Forensic Filter (Macherey-Nagel, Düren) is one such example, but it has not been thoroughly assessed on touch DNA samples. This study aimed to assess if the inclusion of the NucleoSpin® Forensic Filter significantly improved DNA recovery and DNA profiling success from cotton and flocked swabs used to collect touch DNA and buccal cells (control). Buccal cells and touch DNA samples were collected from 25 volunteers using each swab type (cotton and flocked) in duplicate. DNA was extracted from the samples using the NucleoSpin® DNA Forensic kit, one set with, and the other set without, NucleoSpin® Forensic Filters. DNA concentration was assessed using Qubit™ fluorometry and qPCR, and DNA profiling was done using the PowerPlex® ESX 16 system. The inclusion of the NucleoSpin® Forensic Filters significantly improved DNA concentration in buccal cells collected using flocked swabs (p = 0.035). However, no significant differences were noted for touch DNA samples, for either swab type. There was also no significant difference in DNA profiling success when NucleoSpin® Forensic Filters were used, regardless of swab and sample type. These results suggest that the NucleoSpin® Forensic Filters should not be included in the DNA extraction workflow, particularly for touch DNA samples. With only 16 % of touch DNA samples yielding full DNA profiles, there is the need to improve DNA recovery. Factors such as swab type and swab preservation buffers, should be investigated in future research.
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    Investigating the role of alcohol in road traffic collision fatalities in Western Cape, South Africa
    (2020) Malomane, Rixongile; Davies, Bronwen; Mole, Calvin
    Road traffic collisions (RTCs) are a major contributor to unnatural death worldwide, but especially in low-to-middle-income countries (LMICs) where motorised transport has rapidly expanded. A literature review into RTCs and alcohol indicated that it is well recognised that alcohol intoxication is a key risk factor in RTCs and road traffic fatalities (RTFs). It also indicated that literature concerning the role of alcohol intoxication in RTFs in South Africa is limited. Hence, this study aimed to investigate alcohol in RTF victims in five of the major mortuaries (Salt River, Tygerberg, Paarl, Worcester and George) in the Western Cape Province between 1 January 2016 and 31 December 2017. Cases were extracted from the Western Cape Forensic Pathology Service (FPS) internal database, which included demographic and crash information, together with blood alcohol concentration (BAC) results. In total, 2079 cases over the two years were included in the study, with most cases admitted in the metropole of Cape Town (Salt River: n=838, Tygerberg: n=693). The proportion of unnatural deaths were greater outside the metropole (George, Worcester and Paarl) compared to the metropole (Salt River and Tygerberg) areas. The majority of fatalities were male individuals (male to female ratio of 3.52:1), with the average age of 35.2 ± 17.2 years. Most victims were pedestrians (n = 1106; 53.7%) and dark wet roads, and highways were noted as risk factors in RTFs. Blood was submitted for alcohol analysis in 1432 (68.9%) cases, and results were available for 1314 (91.8%) cases. Of the available results, 709 cases (54%) were positive for alcohol (BAC of ≥ 0.01g/100 mL). Of the positive cases, most had a BAC between 0.15 and 0.29 g/100mL and the overall average BAC was 0.20 g/100 mL. Pedestrians and drivers had the highest median BACs, and almost a third of all the positive BAC results were from pedestrian deaths. The findings of this dissertation can contribute to the growing research on alcohol and injury in South Africa, especially as it relates to RTFs. Insight into vulnerable populations within the province is highlighted, together with key risk factors associated with RTFs, as well as safety measures that may be targeted for improvement, especially with regards to driving and walking on the roads while intoxicated.
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    Investigation into X-STR haplotype frequencies for forensic human identification in South Africa
    (2023) Whittaker, Amy-Leigh; Mole, Calvin; Pearce Brendon
    The utilisation of X-chromosome short tandem repeats (X-STRs) for DNA profiling has been demonstrated to be particularly useful in resolving distant familial relations and deficiency paternity testing. The implementation of X-STRs within a medico-legal context requires baseline frequency data for the general population to allow for appropriate statistical interpretations of results. This study aimed to generate the first X-STR data for the South African population andinternally validate the Qiagen Investigator Argus X-12 QS kit. Biological samples from 781 South African individuals (517 males and 264 females) with either African, mixed, European, or Indian/Asian ancestry were processed. Statistical analyses were performed using StatsX and Arlequin. Herein, allele and haplotype frequencies and forensic parameters for the South African population are reported, as well as data related to the reproducibility, sensitivity, limit of detection, and concordance of the Investigator Argus X-12 QS kit. DXS10135 was the most informative locus, while DXS7423 was the least informative locus. The combined power of discrimination for both males and females was greater than 0.999999999. The haplotype diversity of all four linkage groups exceeded 0.993. Linkage group 1 was the most informative, with 421 unique haplotypes. Possible linkage disequilibrium was detected in five loci pairs in male samples and three loci pairs in female samples. However, it is expected that the effects of false linkage disequilibrium were present, and only loci pairs within the same linkage group may be in true linkage disequilibrium. All loci in female samples were in Hardy-Weinberg equilibrium, except DXS10148. Additionally, a total of 59 off-ladder alleles were identified. The discriminatory power of these results suggests X-STRs may be beneficial for forensic casework in South Africa. The availability of this data could allow this method to be used locally to assist with civil inheritance disputes and the identification of unknown individuals.
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    Molecular Forensic Investigations into Animal Sexual Abuse
    (2020) Natha, Khilona; Heathfield, Laura; Mole, Calvin
    Animal sexual abuse (ASA) involves the sexual molestation of animals by humans. The identification of semen provides a legally-accepted indicator that sexual activity occurred, while forensic DNA analysis provides a lead to a potential suspect. After conducting a systematic literature review, no previous research investigating semen and/or DNA recovery from animals over time was found. Therefore, this pilot study aimed to assess the recovery of human semen and DNA from animal fur over a two-week period to establish baseline data pertaining to evidence retention in the ASA context. This pioneer study also attempted to contribute towards the development of a suitable animal fur model on which to perform experiments. Daily swabbing and testing of semen from three fur models (unpreserved baboon fur, preserved nyala hides and faux fur) showed that semen could still be detected at 14 days using standard presumptive and confirmatory tests. Although DNA degradation showed a statistically significant increase over time, forensically usable DNA profiles (≥ 12 fully typed short tandem repeat loci) were consistently obtained. There was significantly higher DNA degradation in samples from the baboon fur compared to the others, while DNA concentrations were significantly different between each fur model. These differences highlight that future research must consider the choice of fur model to best represent the animal of interest; e.g. dissected fur from a recently deceased animal would best mimic a fatal ASA case. The insight regarding the choice of animal model hopes to be of benefit for future research, which should focus on the influence of more realistic variables (e.g. movement and body heat) on semen and DNA retention on animal fur. Overall, this study successfully generated baseline data, and provides a foundation for additional research, which hopes to eventually assist in the interpretation of forensic evidence in the global burden of ASA.
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    Optimisation of sample preparation for DNA extraction from formalin fixed paraffin embedded tissues of unresolved sudden unexpected death cases
    (2020) Viljoen, Rabia; Heathfield, Laura; Mole, Calvin
    A retrospective case review revealed an increase in sudden unexpected death (SUD) admittance at Salt River Mortuary (SRM) between 2014 and 2018, and that 40 % of SUD occurred in young individuals between the ages of 1 and 40 years old (SUDY). Despite extensive investigations, the cause of death remained undetermined in 26 % of SUDY cases. These dormant cases may benefit from retrospective post-mortem molecular autopsies for investigation into genetic causes of death. Often, formalin fixed paraffin embedded tissues (FFPETs) are the only archival sources of DNA available for retrospective analyses. This study aimed to optimise DNA recovery from FFPETs for potential use in molecular autopsies of unresolved SUDY cases. To this end, DNA was extracted from FFPET sections using the QIAamp® DNA FFPE tissue kit; the thickness and number of sections were varied. DNA was assessed using spectrophotometry, real-time PCR and digital capillary electrophoresis. Results showed that finer sectioning (1-µm thick as compared to 3-µm and 5-µm thick), improved DNA concentrations, purities and DNA fragment lengths. Increasing the number of 1-µm thick sections from 30 to 100, significantly improved DNA yield. DNA was not significantly more degraded for FFPETs stored for up to three years, which holds promise in the effectiveness of the technique for aged samples. The DNA extraction method developed in this study yielded a median of 320 ng (287 ng - 698 ng) of DNA with 55 % of DNA fragments being at least 400 bp in size. These results are especially informative for downstream molecular analyses, indicating that genotyping or sequencing assays need to be designed to target amplicons less than 400 bp in size. The degraded nature of the FFPET samples also suggests that massively parallel sequencing might be suited for downstream molecular analysis for determining cause of death in unresolved SUDY cases.
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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 period
    (2018) Majero, T A Tiffany; Mole, Calvin
    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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    The assessment of forensic molecular markers for skin colour in South Africans
    (2020) Vanmali, Akshay; Heathfield, Laura; Mole, Calvin
    The scientific development of innovative molecular techniques has transformed the approach towards human identification. In forensic casework, the emergence of molecular phenotyping, or phenotypic prediction from DNA, has mitigated some challenges involving the unavailability of references samples for traditional forensic DNA analysis. Molecular phenotyping via SNP analysis can be used as a tool in a forensic setting to predict physical traits, such as hair, skin and eye colour, and provide investigative leads. Several ancestry informative markers (AIMs) have previously been associated with human skin colour in mainly the European and North American population groups, while admixed populations are hardly studied. The present study aims to contribute towards this gap by investigating the relationship between two AIMs (SLC45A2, rs16891982 and SLC24A5, rs1426654) that are typically involved in molecular phenotyping, and melanin index (MI) in the South African (SA) metapopulation (n = 389). The self-reported ancestry, ethnicity and relevant biographic information for each participant was documented and MI was recorded using a dermaspectrophotometer. DNA was extracted from saliva samples and PCR amplification of target regions was performed. Thereafter, SNaPshot® PCR was used to genotype the variants. Significant differences (p < 0.0001) were observed between MI readings and ancestral as well as population census groups. A generalised linear model (GLM) was developed which could accurately predicted the MI readings for each genotype combination within the 95 % confidence interval of the recorded MI readings. Our results suggest that these two markers were consistently associated with MI in the admixed SA population and are thus informative to predict MI in a forensic setting. Finally, this was the first study in a SA context to use SNP analysis for objective MI prediction.
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    The correlation between cranial fractures and brain trauma: a retrospective study
    (2024) Sakambana, Sinoyolo; Mole, Calvin; Abrahams, Shameemah
    Traumatic brain injury (TBI) is a global public health concern. TBI has been noted to co-occur with cranial fractures, however this is not always case. At present, there is a gap in literature regarding the correlative relationship between the presence of cranial fracture and brain trauma. The knowledge and understanding of this correlation is imperative for autopsy examinations where pathologists have to determine the cause of death of an individual. Furthermore, in cases where the skeleton is the only tissue that is available for examination, anthropologists will be able to apply this knowledge to infer the presence of brain trauma at death. Therefore, the current study aimed to assess the correlation of cranial fracture and brain injury in cases of blunt force trauma. This was achieved through a retrospective review of blunt force head injury cases of blunt force head injury examined at Salt River Mortuary, Cape Town between 01 January 2015 and 31 December 2019. Co-occurrence of cranial fractures with brain trauma was prevalent in the current study, accounting for 64% of the recorded cases. A significant association was found between age at death and the presence of brain trauma (p = 0.042), with majority of individuals with brain trauma ranging between 18 to 49 years of age. Similarly, a significant association was found between the presence of cranial fractures and age (p = <0.001). A significant association was found between the presence of cranial fractures and brain trauma to the frontal, parietal and temporal lobes (p = <0.001). Moreover, fracture type was significantly associated with the presence of brain trauma. Fractures of the cranial base have an increased risk of being associated with traumatic brain injury compared to the fractures in other regions. Individuals presenting with cranial fracture are 4.48 times more likely to have TBI, compared to those without cranial fracture. Specifically, individuals with fracture of the basal region of the cranium are 3.77 times more likely to have co-occurring TBI. Notably, all cases of hinge fractures had associated brain trauma. The data presented in this study can be used for the prediction of the presence of brain trauma, where the presence of cranial fracture is noted.
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    The effect of burning on pre-incineration trauma in bone
    (2023) Chang, Enya; Mole, Calvin
    The act of burning is a common method of destroying and concealing evidence which may include dismemberment of the body. Saws used during dismemberment leave characteristic marks on bone, the analysis of which can assist in forensic casework. Research that has been conducted to date, provide minimal information on controlled temperatures to analyse and distinguish pre- and post-burning trauma marks. The aim of this research was to assess and compare morphological differences of pre-existing bone trauma before and after burning at various controlled temperatures. In this research, a back saw (tenon saw) was used to manually inflict trauma on de-fleshed Ovis aries femur bones (n = 18). These bones were later exposed to heat at controlled temperatures of 400°C, 600°C and 800°C for 20 minutes. Three different cut marks including a shallow false start, incomplete cut and a complete transection of the bone were inflicted on the mid-shaft of each bone specimen through which 54 lesions were analysed. Differences in saw mark characteristics of the cut surfaces before and after exposure to heat were investigated and compared. The following characteristics were examined: blade drift, bone islands, breakaway spurs, exit chipping, harmonics, kerfs, pull-out striae, striation regularity, tooth hop and profile shape. Quantitative analyses were conducted using macroscopic techniques and stereomicroscope to examine the specific characteristics of the different saw marks. All pre-existing trauma except one cut mark (shallow false start) survived after the burning process. The shallow false start was lost during the burning process and could not be recovered. The saw marks were distinguishable from heat-related fractures in all temperature groups. In some cases, characteristics such as exit chipping, pull-out striae and striation regularity were enhanced post-burning. Nonetheless, the post-burning survival and detection of saw marks can be obscured which may affect the visibility of sharp force trauma. Therefore, additional research for instance burning the bones at different durations and increasing the sample size should be examined. Furthermore, information on other factors and variables such as bone type or burning environment can be collected to create a database to increase accuracy of saw mark analysis.