Abstract in English and Afrikaans / This study has a twofold purpose in that it attempts to identify how knowledgeable investigators are about the collection and use of DNA in relation to the building of a criminal case, and to establish how optimally DNA as evidence is utilised. The study has revealed several shortcomings which render the use of DNA evidence inadmissible in criminal proceedings. The researcher also analysed other aspects relating to DNA evidence, namely: identification, individualisation, criminal investigation, forensic investigation, and objectives of criminal investigation. For criminal investigators to be successful in their investigation of cases involving DNA, it is imperative for them to have a clear understanding of the basic concepts surrounding DNA investigations and the value of DNA evidence. It is submitted that, because of a lack of knowledge in DNA-related investigations by detectives, a lack of training in DNA-related cases and delays in the collection of DNA evidence, valuable evidence is often lost and/or contaminated. This causes such evidence to become inadmissible in criminal proceedings, and has a negative impact on the conviction rate for such crimes. / Hierdie studie het ’n tweevoudige doel in die poging om te identifiseer hoe kundig ondersoekers is aangaande die insameling en gebruik van DNA in terme van die bou van ’n kriminele saak en die vasstel van hoe DNA optimal [sic] as bewys gebruik kan word. Die studie het getoon dat daar verskeie tekortkominge is wat teweeg gebring het dat die gebruik van DNA bewys onaanvaarbaar was in kriminele prosedure. Die navorser het ook ander aspekte geanaliseer aangaande DNA bewyse, naamlik: identifikasie, individualisering van onderwerpe tydens ondersoek, kriminele ondersoek, forensiese ondersoek, en die aspekte van kri-minele ondersoeke. Vir die kriminele ondersoekers om suksesvol te wees in hulle ondersoek van sake waarby DNA betrokke is, is dit vir hulle van kardinale belang om ’n suiwere begrip van die basiese konsep rondom DNA ondersoeke en die waarde van DNA bewyse te hê. Dit is voortgebring dat, as gevolg van die tekort aan kennis in DNA ondersoeke, asook opleiding van DNA-sake by die speurders, en vertraging in die versameling van DNA bewysstukke, waardevolle bewyse is telkens verlore of gekontamineer. Dit veroorsaak dat sulke bewyse verwerp word in kriminele prosesse, en het ’n negatiewe impak op die vonnis statestieke [sic] vir sulke misdade. / Criminology and Security Science / M.Tech. (Forensic Investigation)

No description available.

For millions of people worldwide the use of computers has become a central part of life. Criminals are exploiting these technological advances for illegal activities. This growth of technology has therefore produced a completely new source of evidence referred to as ‘electronic evidence’. In light of this the researcher focused on the collection of electronic evidence and its admissibility at trial. The study intends to assist and give guidance to investigators to collect electronic evidence properly and legally and ensure that it is admitted as evidence in court. Electronic evidence is fragile and volatile by nature and therefore requires the investigator always to exercise reasonable care during its collection, preservation and analysis to protect its identity and integrity. The legal requirements that the collected electronic evidence must satisfy for it to be admissible in court are relevance, reliability, and authenticity. When presenting the evidence in court the investigator should always keep in mind that the judges are not specialists in the computing environment and that therefore the investigator must be able to explain how the chain of custody was maintained during the collection, preservation and analysis of electronic evidence. The complex technology behind electronic evidence must be clearly explained so that the court is able to understand the evidence in a way that an ordinary person or those who have never used a computer before can. This is because the court always relies on the expertise of the investigator to understand electronic evidence and make a ruling on matters related to it. / Police Practice / M. Tech. (Forensic Investigation)

Condom trace evidence must not be overlooked in sexual assault cases; understanding the chemical and physical characteristics of condoms is imperative if condoms are to be useful evidence. Previous research shows that condom identification is possible, but it is equally important to evaluate durability of condom residues versus time. Using FT-IR, this study examined vaginal swabs from subjects who self-sampled at intervals for up to 72 hours after having intercourse with a condom. This study investigated whether age and the stage of the menstrual cycle affected the durability of residues in the vagina over time. This study revealed that condoms containing nonoxynol-9, silicone-based lubricants, and particulates provide valuable information for identification, and that nonoxynol-9 specifically withstands the vaginal environment for up to 72 hours. Additionally, age and menstrual cycle both appeared to have an effect on the durability of residues although larger sample size is desirable.

La physique de mouillage et de séchage de sang n’est pas encore bien connue. Dans le cadre d’un travail collaboratif, une étude est réalisée afin d’apporter de nouveaux outils aux équipes d’investigations criminelles. L’objectif est de comprendre les dynamiques qui entrent en jeu dans la formation de traces de sang, un fluide complexe. Nous nous intéressons aux traces dites passives telles que l’égouttement ou l’accumulation, qui résultent de l’action de la pesanteur. Nous considérons d’abord les gouttes passives. Le comportement d’impact de gouttes de fluides complexes est un sujet qui a été largement étudié mais suscite encore de vifs débats. Bien que le séchage d’une goutte déposée ait déjà été étudié, ceci n’est pas le cas pour des gouttes qui viennent impacter perpendiculairement une surface, tombant depuis une certaine hauteur. Parallèlement nous étudions le séchage de flaques de sang car leur dynamique de séchage n’a pas été étudiée jusqu’à présent. Différents paramètres tels que la nature des substrats, l’humidité et la température sont pris en compte afin de comprendre le lien entre la typologie des motifs séchés et les phénomènes observés en vue de répondre à des applications criminelles. Enfin des relations empiriques sont établies. Grace à des méthodes inverses, ces relations permettent, par la suite, d’obtenir une estimation de la vitesse d’impact de gouttes séchées. / The physics behind wetting and drying of blood is not yet completely understood. In the context of a collaborative project, new techniques have been developed to provide evidence for investigators in crime solving. Given that blood is a complex fluid, the major aim has been to investigate the dynamics involved in the patterns of stain formation. Interest is focused on passive stains, which result from the action of gravity in dripping or blood flow accumulation. In the case of drip stains, the impact behaviour of complex fluid droplets, despite many studies, raises much debate. Although the drying dynamics of a deposited drop of blood were already studied, this is not the case for drops of blood impacting perpendicularly a surface, falling from a certain height. Beside this, until the present work, little attention has been paid to the dynamics controlling the drying of blood pools. In both situations, the influence of different parameters such as substrates, humidity and temperature are examined. Empirical relations are established between final dried blood patterns and the generating mechanism, yielding possible application in blood pattern analysis for forensic investigations. Finally, using inverse methods, the empirical relations allow estimating an impact velocity, for dried drip stains.

Introdução - A morte violenta permeia o cotidiano do cidadão brasileiro, assim como o cotidiano laboral das equipes da perícia criminal do município de São Paulo. Os servidores forenses têm como atribuição representar o Estado na execução pericial dos locais de crimes envolvendo vítimas humanas. Objetivo - Compreender as práticas cotidianas do trabalho pericial, identificando a percepção dos fatores de risco e as estratégias de trabalho imbuídos no atendimento pericial da morte violenta. Métodos - Pesquisa qualitativa com perspectiva etnográfica. Os registros empíricos são oriundos das anotações etnográficas em diário de campo de 61 locais de crimes periciados pela equipe de peritos criminais e fotógrafos técnico-periciais do Núcleo de Perícias em Crimes contra a Pessoa do Instituto de Criminalística do município de São Paulo. Entrevistas individuais semiestruturadas foram realizadas com 28 servidores periciais. De modo complementar, aplicou-se um formulário para caracterização sociodemográfica dos participantes. Reportagens veiculadas nas mídias digitais e impressas foram utilizadas como dados secundários. Os dados foram analisados por meio de codificação temática. Para tal, utilizou-se o software MAXQDA, versão 18. Resultados - As naturezas criminais predominantes nas requisições periciais foram: morte suspeita, suicídio e homicídio de autor conhecido. A idade dos participantes variou entre 28 e 65 anos, e o tempo de experiência na perícia variou entre 1 e 31 anos. O perfil do público foi predominantemente do sexo masculino, casado com filhos e possuidor de alguma crença religiosa. O treinamento profissional fornecido pelo Instituto de Criminalística variou de 3 a 12 meses. Com relação à pesquisa empírica, a codificação do material nos conduziu a quatro categorias temáticas: 1) A atividade do trabalho pericial; 2) Crimes periciados; 3) Violência naturalizada; 4) Amplificação da violência pela mídia. Os relatos e as observações em campo revelaram práticas cotidianas de um trabalho perigoso e insalubre nos sentidos biológico e psíquico. Ao lidarem com o corpo da vítima de violência letal, as equipes são expostas à vitimização direta e indireta. Atuam em escalas de trabalho extensas, com déficit de servidores, tempo de recuperação curto e relatos de presenteísmo. A falta de transparência no planejamento da carreira forense somada aos significados de ser policial forense foram mobilizadores de sentimentos e ressignificados ao longo da trajetória profissional. Fatores de risco foram revelados, como: riscos associados à categoria policial; antevisão do processo de morrer ao se sentirem suscetíveis à naturalização da violência urbana; amplificação da violência pela mídia, que reverbera discursos estereotipados sobre a ação policial e sobre os \"bandidos\", incitando o ódio; manifestação de sentimento de não reconhecimento institucional. Os participantes revelaram que criam estratégias visando conciliar tais dimensões com a manutenção de sua saúde, sendo elas: sublimação, desconstrução do herói, uso do humor cítrico, distanciamento e não pertencimento à realidade da periferia e valorização da vida em sua simplicidade. Conclusão - Atuar na perícia criminal exige que o trabalhador desenvolva estratégias coletivas e individuais constantemente, pois a violência e os crimes não são estáticos. O Instituto de Criminalística vivencia uma reestruturação em seu organograma que impacta diretamente a operação pericial. Faz-se necessário oferecer ações psicológicas preventivas e treinamento contínuo aos servidores periciais no sentido de manter a saúde desses trabalhadores. / Introduction - Violent death permeates the daily life of the Brazilian citizens as well as the daily routine of the criminal investigation teams of the municipality of São Paulo. The forensic servers have to represent the State, as attribution, in the expert execution in the sites of crimes involving human victims. Objective - to understand the daily practices of the expert work, identifying risk factors and work strategies imbued in the expert assistance of violent death. Methods - Qualitative research with an ethnographic perspective. The empirical records are derived from the ethnographic field work diary notes of 61 crime sites, experienced together with the on-call staff. These crime sites were investigated by the team of criminal experts and technical-expert photographers who belong to the Center for Expertise in Crimes against the Person (NPCCPessoa) of the Institute of Criminalistics (IC) of the city of São Paulo. Individual semi-structured interviews were conducted with 28 expert servers. In a complementary way, a form of sociodemographic characterization of the participants was applied. Reports on digital and printed media were used as secondary data. Data were analysed using thematic coding. For that, the software MAXQDA, version 18 was used. Results - The predominant criminal natures in the investigative requisitions were: suspicious death, suicide and homicide of a known perpetrator. The age of the participants ranged from 28 to 65 years and the time of experience in the profession is between 1 to 31 years. The participants are predominantly composed by males, married, with children and most of them have a religious belief. The professional training provided by the Institute of Criminalistics varied from 03 to 12 months. With regard to empirical research, the codification of the material generated four thematic categories: 1) The activity of the expert work; 2) Crimes that underwent expert work; 3) Naturalized violence; 4) Amplification of violence by the media. The reports and field observations revealed daily practices of a dangerous and unhealthy work in the biological and psychological senses. The teams dealing with the body of a victim of lethal violence are exposed to a direct and indirect victimization. They work with extensive work scales, server shortages, short recovery times and present-day reports. The lack of transparency in the planning of the forensic career added to the meaning of being a forensic police worker were mobilizers of feelings such as non-recognition and institutional belonging, which were re-signified throughout their professional trajectory. Risk factors were revealed, such as: risks in belonging to the police category itself; the anticipation of the process of dying when they feel susceptible to the naturalized urban violence; the amplification of media violence by reverberating stereotyped discourses about police action and \"bad guys\", inciting hatred. The participants revealed that they created strategies to reconcile these dimensions with the maintenance of their health, such as: sublimation, deconstruction of the hero, use of dark humor, creating distance, not belonging to the reality of the periphery, valorisation of life in its simplicity. Conclusion - Acting in the criminal expertise requires that the worker constantly develop strategies, collectively and individually, as violence and crimes are renewed. The IC experiences a restructuring in its organization chart that directly impacts on the expert operations. It is necessary to offer preventive psychological actions and continuous training to the expert servants in the sense of maintaining the health of these workers. To the managers, it is suggested mobilization to plead legislations that, in fact, untie the IC from the Civil Police, as well as a modernization of the work processes.

Computer forensic tools have been developed to enable forensic investigators to analyse software artefacts to help reconstruct possible scenarios for activity on a particular computer system. A number of these tools allow the examination and analysis of system generated artefacts such as the Windows registry. Examination and analysis of these artefacts is focussed on recovering the data extracting information relevant to a digital investigation. This information is currently underused in most digital investigations. With this in mind, this thesis considers system generated artefacts that contain information concerning the activities that occur on a Windows system and will often contain evidence relevant to a digital investigation. The objective of this research is to develop an architecture that simplifies and automates the collection of forensic evidence from system generated files where the data structures may be either known or in a structured but poorly understood (unknown) format. The hypothesis is that it should be feasible to develop an architecture that will be to integrate forensic data extracted from a range of system generated files and to implement a proof of concept prototype tool, capable of visualising the Event logs and Swap files. This thesis presents an architecture to enable the forensic investigator to analyse and visualise a range of system generated artefacts for which the internal arrangement of data is either well structured and understood or those for which the internal arrangement of the data is unclear or less publicised (known and not known data structures). The architecture reveals methods to access, view and analyse system generated artefacts. The architecture is intended to facilitate the extraction and analysis of operating system generated artefacts while being extensible, flexible and reusable. The architectural concepts are tested using a prototype implementation focussed the Windows Event Logs and the Swap Files. Event logs reveal evidence regarding logons, authentication, account and privilege use and can address questions relating to which user accounts were being used and which machines were accessed. Swap file contains fragments of data, remnants or entire documents, e-mail messages or results of internet browsing which reveal past user activities. Issues relating to understanding and visualising artefacts data structure are discussed and possible solutions are explored. The architecture is developed by examining the requirements and methods with respect to the needs of computer forensic investigations and forensic process models with the intention to develop a new multiplatform tool to visualise the content of Event logs and Swap files. This tool is aimed at displaying data contained in event logs and swap files in a graphical manner. This should enable the detection of information which may support the investigation. Visualisation techniques can also aid the forensic investigators in identifying suspicious events and files, making such techniques more feasible for consideration in a wider range of cases and, in turn, improve standard procedures. The tool is developed to fill a gap between capabilities of certain other open source tools which visualise the Event logs and Swap files data in a text based format only.

published_or_final_version / Computer Science / Doctoral / Doctor of Philosophy

The tendency of members under the South African Police Services (SAPS) to obtain tertiary qualifications relevant to policing has declined due to SAPS promotion policy. Those who do further their educations enroll into fields that will assist them to obtain employment outside of SAPS. The Forensic Science Laboratory (FSL) under SAPS is solely responsible for the analysis of the police investigating officer’s evidence it receives. It is thus critical that FSL analysts are motivated and have high levels of commitment. This study will attempt to determine if SAPS promotion policy has an impact on the level of commitment of forensic analysts, with the aim of suggesting and recommending a Human Resource Management (HRM) policy or practice that will maintain or improve the level of commitment of Forensic analysts. The quantitative research approach was employed, and questionnaires were distributed to forensic analysts in FSL in KwaZulu-Natal (KZN). The study was important in gaining insight into the impact of SAPS promotion policy on organisational commitment of forensic analysts, and to understand what form or type of organisational commitment that drives continuous participation of analysts in the organisation. A probability sample of sixty six (66) forensic analysts was drawn from FSL in KZN (Amanzimtoti) with a population size of eighty (80) analysts. FSL-KZN was chosen because of the convenience access to the study sample and since provincial FSL’s are mostly affected by promotion policy procedure. Data was collected using questionnaires which were physical distributed by the researcher. The promotion policy was measured using promotion policy scale developed by the researcher together with biographical variables questionnaire such as age, gender, marital status, tenure, level of education and ranks level. Organisational commitment was measured using the Meyer and Allen (1991) Organisational Commitment Questionnaire. The study revealed that SAPS promotion policy has a significant impact on organisational commitment (affective and normative commitment) but no significant impact on continuance commitment. The study also showed no significant difference between some of biographical variables and organisational commitment (affective, normative and continuance commitment) and that continuance commitment was the most dominant form of commitment that drive analysts to continue to work for FSL. The study results could play an important role to managers who want to implement HRM practices and promotion policy that enhance the organisational commitment of employees with high expertise and skills such as FSL forensic analysts under SAPS. / Thesis (MBA)-University of KwaZulu-Natal, Durban, 2012.

[Truncated abstract] Palynology has been used in a number of criminal cases where pollen and spores (palynomorphs) on clothing has featured as evidence. Pollen and spores are microscopic, generally morphologically unique to a plant genus and often species, resistant to decay, produced in large amounts and are components of soil. These unique features of pollen and spores make palynology a highly valuable forensic tool. Clothing is an excellent collector of pollen and spores as they become trapped in the fabric weave when clothing is brushed against flowering plants, comes into contact with dust, soil or air-borne pollen. Most forensic palynologists have found that palynomorphs from a crime scene may remain on clothing after washing or several days wear. No empirical research has been conducted on the retention of palynomorphs on clothing under differing conditions. Research of this kind is required to provide support for the future presentation and validation of palynological evidence in court. This project examined the relative retention of palynomorphs on clothing that had been worn during a simulated assault in a sheltered garden on the grounds of St George's College, Western Australia. Three replicate control soil samples each were collected from the actual assault scene and the whole garden to provide a baseline palynological profile for comparison to the experimental (Evidentiary) clothing samples. Forty pollen samples from the predominant species of plants in the garden and surrounds were collected, processed and databased as a reference for palynomorph identification. Standard T-shirts and jeans were chosen as the research clothing. During the simulated assault the knees of the jeans and the backs of the T-shirts came into abrasive contact with the soil of the garden for approximately one minute. The clothing then underwent three 'conditions' to simulate 'real life' situations. Three clothing sets were immediately collected after the assault (E1), three sets were worn for a period of three days after the assault (E2) and three sets were washed after the assault (E3). ... The Background clothing samples did not have a profile similar to the research garden but the profiles collected from each set reflected the areas to which they were worn. The number of palynomorphs per gram of garden soil ranged from thousands to tens-of-thousands of palynomorphs. The total number of palynomorphs collected by the E1 samples ranged from 100,000 to millions per clothing item. The E2 samples retained 1000's to tens-of-thousands of palynomorphs and the E3 samples retained 100's to 1000's of palynomorphs. The background clothing samples collected 1000's to tens-of-thousands of palynomorphs. These results confirm that jeans and T-shirts worn during an assault then worn for a period of days, or washed, will still contain pollen and spores characteristic of the assault area. This highlights the importance of investigating police enquiring where and for how long clothing of interest has been worn before and after an event, or if the clothing has been washed since the event. The results of this study will provide forensic palynologists with supportive data for future casework involving clothing.