• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 132
  • 19
  • 11
  • 5
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 183
  • 183
  • 75
  • 75
  • 60
  • 53
  • 52
  • 48
  • 36
  • 30
  • 29
  • 29
  • 25
  • 23
  • 20
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Metodologia para análise na perícia criminal de microvestígios forenses: fios de cabelo / Method for criminal exam analysis in forensic trace: hair

Lara, Alexandre Guilherme de 19 March 2016 (has links)
A presente dissertação expositiva teve por objetivo o desenvolvimento de metodologia para análise forense de fios de cabelos. Considerado um microvestígio comum de ser encontrado em locais de crime contra pessoa (DOREA, 2010), fios de cabelo são capazes de fornecer informações úteis na identificação da autoria do crime, ou a entender a dinâmica de um crime violento (ROBERTSON, 1999). As fibras compostas por fio de cabelo deterioram-se lentamente (ROBBINS, 2012), e podem ser analisadas mesmo transcorrido longo período de tempo, tornando-se ainda mais relevante em locais de crime que são examinados tardiamente. Os equipamentos utilizados no presente estudo são de uso comum em laboratórios, permitindo que a metodologia seja amplamente empregada. O presente estudo buscou desenvolver metodologias para análise por microscopia ótica de fios de cabelo, identificando as características de interesse forense passíveis de serem estudadas. Utilizaram-se amostras de fios de cabelo para análise das seções transversais e longitudinais, de forma destrutiva e não destrutiva, com preparação de lâminas de forma permanente e não permanente. Como resultado obteve-se uma metodologia de baixo custo descrita para aplicações forenses em vestígios coletados em locais de crime, em armas de crimes ou em suspeitos, de forma a combater a criminalidade face o poder probatório da prova material. Constatou-se a possibilidade de identificação de características macroscópicas e microscópicas de fios de cabelo, que revelam atributos do doador e, em alguns casos, auxiliar no entendimento da dinâmica do crime. A agilidade observada no método permite ainda a obtenção de informações durante a fase preliminar ou de investigação em curtos espaços de tempo. / This monographic dissertation aimed to develop standards of microscopic forensic hair analysis. A very common trace to be found in certain crimes (DOREA, 2010), hair can be helpful to provide information regarding the perpetrator or the way that the crime was committed (ROBERTSON, 1999). Once hair is a low degradation fiber (ROBBINS, 2012), it can be analyzed long after the fact, becoming even more relevant in crime scenes processed after elapse time. The equipment’s used for this study are commonly found in forensic labs, allowing broad use. The study was restricted to literature review and further elaboration of preparation and analysis by optical microscopy of hairs methods, identifying the characteristics of forensic interest that can be studied. Samples of hair for cross section and longitudinal sections analysis had been used. Destructive and non-destructive methods in permanent and non-permanent blades where tested. As a result a low cost methodology was obtained for forensic applications in traces collected from crime scenes, weapons used in crimes or suspects, in order to combat crime by using the probative power of physical evidence.
132

Metodologia para análise na perícia criminal de microvestígios forenses: fios de cabelo / Method for criminal exam analysis in forensic trace: hair

Lara, Alexandre Guilherme de 19 March 2016 (has links)
A presente dissertação expositiva teve por objetivo o desenvolvimento de metodologia para análise forense de fios de cabelos. Considerado um microvestígio comum de ser encontrado em locais de crime contra pessoa (DOREA, 2010), fios de cabelo são capazes de fornecer informações úteis na identificação da autoria do crime, ou a entender a dinâmica de um crime violento (ROBERTSON, 1999). As fibras compostas por fio de cabelo deterioram-se lentamente (ROBBINS, 2012), e podem ser analisadas mesmo transcorrido longo período de tempo, tornando-se ainda mais relevante em locais de crime que são examinados tardiamente. Os equipamentos utilizados no presente estudo são de uso comum em laboratórios, permitindo que a metodologia seja amplamente empregada. O presente estudo buscou desenvolver metodologias para análise por microscopia ótica de fios de cabelo, identificando as características de interesse forense passíveis de serem estudadas. Utilizaram-se amostras de fios de cabelo para análise das seções transversais e longitudinais, de forma destrutiva e não destrutiva, com preparação de lâminas de forma permanente e não permanente. Como resultado obteve-se uma metodologia de baixo custo descrita para aplicações forenses em vestígios coletados em locais de crime, em armas de crimes ou em suspeitos, de forma a combater a criminalidade face o poder probatório da prova material. Constatou-se a possibilidade de identificação de características macroscópicas e microscópicas de fios de cabelo, que revelam atributos do doador e, em alguns casos, auxiliar no entendimento da dinâmica do crime. A agilidade observada no método permite ainda a obtenção de informações durante a fase preliminar ou de investigação em curtos espaços de tempo. / This monographic dissertation aimed to develop standards of microscopic forensic hair analysis. A very common trace to be found in certain crimes (DOREA, 2010), hair can be helpful to provide information regarding the perpetrator or the way that the crime was committed (ROBERTSON, 1999). Once hair is a low degradation fiber (ROBBINS, 2012), it can be analyzed long after the fact, becoming even more relevant in crime scenes processed after elapse time. The equipment’s used for this study are commonly found in forensic labs, allowing broad use. The study was restricted to literature review and further elaboration of preparation and analysis by optical microscopy of hairs methods, identifying the characteristics of forensic interest that can be studied. Samples of hair for cross section and longitudinal sections analysis had been used. Destructive and non-destructive methods in permanent and non-permanent blades where tested. As a result a low cost methodology was obtained for forensic applications in traces collected from crime scenes, weapons used in crimes or suspects, in order to combat crime by using the probative power of physical evidence.
133

Desenvolvimento das competências técnicas dos peritos documentoscópio da Polícia Federal

Lima, Narumi Pereira 01 November 2013 (has links)
Submitted by NARUMI PEREIRA LIMA (narumi.npl@gmail.com) on 2014-01-13T12:46:43Z No. of bitstreams: 1 Dissertacao Narumi.pdf: 1461948 bytes, checksum: 4b7bfe9ac90a500a203cfd88ede7b5d1 (MD5) / Approved for entry into archive by Janete de Oliveira Feitosa (janete.feitosa@fgv.br) on 2014-01-22T13:28:18Z (GMT) No. of bitstreams: 1 Dissertacao Narumi.pdf: 1461948 bytes, checksum: 4b7bfe9ac90a500a203cfd88ede7b5d1 (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2014-01-23T17:27:03Z (GMT) No. of bitstreams: 1 Dissertacao Narumi.pdf: 1461948 bytes, checksum: 4b7bfe9ac90a500a203cfd88ede7b5d1 (MD5) / Made available in DSpace on 2014-01-23T17:27:14Z (GMT). No. of bitstreams: 1 Dissertacao Narumi.pdf: 1461948 bytes, checksum: 4b7bfe9ac90a500a203cfd88ede7b5d1 (MD5) Previous issue date: 2013-11-01 / The Forensic Document Examination is the major forensic area of Federal Police Criminalistics, been responsible for 24,49% of the total amount of technical reports in the Criminalistics National System. Nevertheless, it does not have specific selection area or graduation, and the development of its competences depend almost exclusively on the training offered and performed internally, inside the institution and the workplace. Considering the Federal Police General Direction and Technical-Scientific Direction strategic plannings, that expressed the relevance of the servants professional development through continuous training and competence management as strategies to reach their missions, it is possible to notice how important is the proper study and development of the forensic document examination competences. This purpose of this research is to analyze if the technical competences of the Federal Police forensic document examiners that has been described in the technical activity matrix are in consonance with the ones described by UN, and if these competences have been developed by the training courses offered by National Police Academy. It was identified some gaps, i.e., UN recommendations that are in accordance with the matrix, but are no developed in the training courses, besides some discrepancies in the courses duration. Some suggestions were made for minimize or eliminate these gaps, as well as another considerations related to more training offer, professional specialization, and proficiency tests and mentoring implementation. / A Documentoscopia é a maior área de perícia da Criminalística da PF, respondendo por 24,49% de toda a produção de laudos do Sistema Nacional de Criminalística. Apesar disso, não possui área de concurso ou graduação específicas, e o desenvolvimento das competências da área depende quase que exclusivamente da capacitação oferecida e executada internamente, dentro da instituição e do ambiente de trabalho. Considerando os planejamentos estratégicos da Direção Geral e da Diretoria Técnico-Científica da PF, que manifestaram a importância da valorização de seus servidores por meio da capacitação contínua e da gestão de competências como estratégia para se alcançar suas missões, vê-se a relevância no adequado estudo e desenvolvimento das competências na área da perícia documentoscópica. O presente trabalho tem por objetivo analisar se as competências técnicas dos peritos documentoscópico da Polícia Federal elencadas na matriz da função técnica da PF estão em consonância com as elencadas pela ONU para os examinadores forenses de documentos, e se essas competências estão sendo desenvolvidas nas ações de capacitação oferecidas pela ANP voltadas para a área. Foram identificadas algumas lacunas, ou seja, recomendações da ONU que encontram correspondência nas elencadas na matriz, mas não são desenvolvidas pelas ações de capacitação, além da discrepância quanto à carga horária dos cursos. Algumas sugestões para a minimização ou eliminação dessas lacunas foram colocadas, e outras considerações foram feitas, principalmente voltadas à maior oferta de capacitação, à especialização profissional, à instituição de testes de proficiência e da mentoria.
134

A critical review of the current state of forensic science knowledge and its integration in legal systems

Venter, Casper Henderik 30 September 2020 (has links)
Forensic science has a significant historical and contemporary relationship with the criminal justice system. It is a relationship between two disciplines whose origins stem from different backgrounds. It is trite that effective communication assist in resolving underlying problems in any given context. However, a lack of communication continues to characterise the intersection between law and science. As recently as 2019, a six-part symposium on the use of forensic science in the criminal justice system again posed the question on how the justice system could ensure the reliability of forensic science evidence presented during trials. As the law demands finality, science is always evolving and can never be considered finite or final. Legal systems do not always adapt to the nature of scientific knowledge, and are not willing to abandon finality when that scientific knowledge shifts. Advocacy plays an important role in the promotion of forensic science, particularly advocacy to the broader scientific community for financial support, much needed research and more testing. However, despite its important function, advocacy should not be conflated with science. The foundation of advocacy is a cause; whereas the foundation of science is fact. The objective of this research was to conduct a qualitative literature review of the field of forensic science; to identify gaps in the knowledge of forensic science and its integration in the criminal justice system. The literature review will provide researchers within the field of forensic science with suggested research topics requiring further examination and research. To achieve its objective, the study critically analysed the historical development of, and evaluated the use of forensic science evidence in legal systems generally, including its role regarding the admissibility or inadmissibility of the evidence in the courtroom. In conclusion, it was determined that the breadth of forensic scientific knowledge is comprehensive but scattered. The foundational underpinning of the four disciplines, discussed in this dissertation, has been put to the legal test on countless occasions. Some gaps still remain that require further research in order to strengthen the foundation of the disciplines. Human influence will always be present in examinations and interpretations and will lean towards subjective decision making. / Jurisprudence / D. Phil.
135

The psychological effects experienced by computer forensic examiners working with child pornography

Whelpton, Juliette 02 1900 (has links)
Convergence of technology has made access to the Internet faster, easier and cheaper. Criminals, including paedophiles, child abusers and pornography traders make use of this technology to commit criminal offences. Computer Forensic Examiners (CFEs) are members of the Cyber Crime Unit, a professional, specialised unit of the South African Police Service (SAPS) who are responsible for computer forensic examination including the investigation of child pornographic images. The aim of the study was to seek understanding on what psychological effects the CFEs experienced when working with the images and was conducted from within the social constructionism and the narrative frameworks. The images had a severe impact on the CFEs as was clearly uncovered in the stories of six CFEs who participated in this study. The participants' stories were recorded and transcribed after which the application of thematic content analysis found that the participants all suffered similar negative effects. These findings were integrated with the findings of a focus group as well as with the findings of a similar study that was conducted during the same time by the Crimes against Children Research Center at the University of New Hampshire and resulted in identifying symptoms of trauma and stress experienced by the CFEs. Based on these results recommendations regarding the support for the CFEs were made. / Psychology / M.A. (Psychology)
136

Discrimination of color copier/laser printer toners by Raman spectroscopy and subsequent chemometric analysis

Feldmann, Jeanna Marie 20 November 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Toner analysis has become an area of increased interest due to the wide availability of laser printers and photocopiers. Toner is most often encountered on paper in questioned document analysis. Because of this, it is important to develop methods that limit the interference of paper without damaging or destroying the document. Previous research using Fourier transform infrared spectroscopy (FTIR) has differentiated toners based on their polymer resin components. However, Raman spectroscopy and chemometric analysis are not typically used for the examination of this material. Raman spectroscopy is a popular tool for the chemical analysis of pigmented samples and was used to characterize cyan, yellow, and magenta toners. Analyses were performed using a dispersive micro-Raman spectrometer equipped with a 785nm diode laser, a CCD detector, and an objective at 20X magnification. One hundred samples of each color toner were collected. Three different and separate methods were developed for cyan, yellow, and magenta toners on paper to optimize results. Further analysis of the magenta toners was excluded due to a weak signal and significant paper interference. The data collected from the analyses of the blue and yellow toners was then processed using a combination of statistical procedures, including principal component analysis (PCA), agglomerative hierarchal clustering (AHC), and discriminative analysis (DA). Ninety-six blue toners were analyzed by PCA and three classes of spectra were suggested. Discriminant analysis showed that the three classes were well-differentiated with a cross-validation accuracy of 100% for the training set and 100% cross-validation accuracy for the external validation set. Eighty-eight yellow toners were analyzed by AHC and four classes of spectra were suggested. Discriminant analysis showed good differentiation between the classes with a cross-validation accuracy of 95.45% for the training set, but showed poor differentiation for the external validation set with a cross-validation accuracy of 72%. While these toners were able to be discriminated, no correlation could be made between the manufacturer, printer make and model, and the toner sample.
137

The room temperature evaporation behavior of purported azeotropes used as cleaning solutions in art conservation

Carrison, Megan Sara January 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Finely-tuned solvent mixtures are used by art conservators for the difficult task of safely and selectively removing yellowed varnish, disfiguring grime, and discolored overpaint from the surface of oil paintings. This process is often referred to as “picture cleaning” and depends on the different solubilities of the obfuscating surface materials and the underlying paint medium. However, differential evaporation rates for the solvents used in these carefully formulated cleaning mixtures can change the potency of the mixture over time, which could potentially lead to solutions having solubility characteristics that are ineffective at cleaning, or worse yet, are deleterious to artists’ oil paints. Azeotropic blends of solvents have been proposed as an alternative for maintaining consistent solvent composition throughout the evaporation process while benefiting from their high vapor pressure relative to the pure solvents. Azeotropes are specific combinations of two or more solvents at a precise concentration that behave as a single solvent, maintaining a constant composition in both the liquid and vapor phases. The use of purportedly azeotropic solvent blends has appeared in the art conservation literature for the cleaning of historic objects and paintings. However, these solvent mixtures are taken from tables of azeotropic compositions given at their boiling point. We have studied one of these solutions, a 19:81 vol% mixture of isopropanol and n-hexane. For the first time, the actual evaporation behavior of this purported azeotropic mixture was followed in detail at room temperature conditions. Through the use of rudimentary vapor pressure measurements, gravimetric analysis, as well as sophisticated compositional determinations of both the liquid phase and headspace of evaporating mixtures by gas chromatography, this particular cleaning solution has been shown to be zeotropic (i.e. NOT an azeotrope) under the conditions typical of conservation studios. The true room temperature azeotropic composition was found instead to contain half as much isopropanol at 9.5 vol%. Art conservators should therefore be dubious of purportedly azeotropic mixtures reported at boiling points well above room temperature. Individual azeotropic cleaning blends are best determined chemically prior to their use in art restoration. Furthermore, the introduction of a model paint film to the evaporating room temperature azeotrope was shown to further confound its behavior, calling into question whether solvent systems can be configured to evaporate with constant composition from the surface of an artwork.
138

Multivariate Statistical Methods Applied to the Analysis of Trace Evidence

Szkudlarek, Cheryl Ann 22 August 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The aim of this study was to use multivariate statistical techniques to: (1) determine the reproducibility of fiber evidence analyzed by MSP, (2) determine whether XRF is an appropriate technique for forensic tape analysis, and (3) determine if DART/MS is an appropriate technique for forensic tape analysis. This was achieved by employing several multivariate statistical techniques including agglomerative hierarchical clustering, principal component analysis, discriminant analysis, and analysis of variance. First, twelve dyed textile fibers were analyzed by UV-Visible MSP. This analysis included an inter-laboratory study, external validations, differing preprocessing techniques, and color coordinates. The inter-laboratory study showed no statistically significant difference between the different instruments. The external validations had overall acceptable results. Using first derivatives as a preprocessing technique and color coordinates to define color did not result in any additional information. Next, the tape backings of thirty-three brands were analyzed by XRF. After chemometric analysis it was concluded that the 3M tapes with black adhesive can be classified by brand except for Super 33+ (Cold Weather) and Super 88. The colorless adhesive tapes were separated into two large groups which were correlated with the presence of aluminosilicate filler. Overall, no additional discrimination was seen by using XRF compared to the traditional instrumentation for tape analysis previously published. Lastly, the backings of eighty-nine brands of tape were analyzed by DART/MS. The analysis of the black adhesive tapes showed that again discrimination between brands is possible except for Super 33+ and Super 88. However, now Tartan and Temflex have become indistinguishable. The colorless adhesive tapes again were more or less indistinguishable from one another with the exception of Tuff Hand Tool, Qualpack, and a roll of 3M Tartan, which were found to be unique. It cannot be determined if additional discrimination was achieved with DART/MS because the multivariate statistical techniques have not been applied to the other instrumental techniques used during tape analysis.
139

Blood on FTA™ Paper: Does Punch Location Affect the Quality of a Forensic DNA Profile?

Carter, Megan Elizabeth 06 March 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Forensic DNA profiling is widely used as an identification tool for associating an individual with evidence of a crime. Analysis of a DNA sample involves observation of data in the form of an electropherogram, and subsequently annotating a DNA “profile” from an individual or from the evidence. The profile obtained from the evidence can be compared to reference profiles deposited in a national DNA database, which may include the potential contributor. Following a match, a random match probability is calculated to determine how common that genotype is in the population. This is the probability of obtaining that same DNA profile by sampling from a pool of unrelated individuals. Each state has adopted various laws requiring suspects and/or offenders to submit a DNA sample for the national database (such as California’s law that all who are arrested must provide a DNA sample). These profiles can then be associated with past unsolved crimes, and remain in the database to be searched in the event of future crimes. In the case of database samples, a physical sample of the offender’s DNA must be kept on file in the laboratory indefinitely so that in the event of a database hit, the sample is able to be retested. Current methods are to collect a buccal swab or blood sample, and store the DNA extracts under strict preservation conditions, i.e. cold storage, typically -20° C. With continually increasing number of samples submitted, a burden is placed on crime labs to store these DNA extracts. A solution was required to help control the costs of properly storing the samples. FTA™ paper was created to fulfill the need for inexpensive, low maintenance, long term storage of biological samples, which makes it ideal for use with convicted offender DNA samples. FTA™ paper is a commercially produced, chemically treated paper that allows DNA to be stored at room temperature for years with no costly storage facilities or conditions. Once a sample is required for DNA testing, a small disc is removed and is to be used directly in a PCR reaction. A high quality profile is important for comparing suspect profiles to unknown or database profiles. A single difference between a suspect and evidentiary sample can lead to exclusion. Unfortunately, the DNA profile results yielded from the direct addition have been unfavorable. Thus, most crime laboratories will extract the DNA from the disc, leading to additional time and cost to analyze a reference sample. Many of the profiles from the direct addition of an FTA™ disc result in poor quality profiles, likely due to an increase in PCR inhibitors and high concentrations of DNA. Currently, standardized protocols regarding the recommended locations for removal of a sample disc from a bloodspot on an FTA™ card does not exist. This study aims to validate the optimal location by comparing DNA profiles obtained from discs removed from the center, halfway, and edge locations of a bloodspot from 50 anonymous donors. Optimal punch location was first scored on the number of failed, partial or discordant profiles. Then, profile quality was determined based on peak characteristics of the resulting DNA profiles. The results for all three disc locations were 5.3% failed amplifications, 4.2% partial amplifications, and one case of a discordant profile. Profile quality for the majority of the samples showed a high incidence of stutter and the absence of non-template adenylation. Of the three disc locations, the edge of the blood stain was ideal, due to a presumably lower concentration of DNA and likely more dilute amount of the PCR inhibitor heme. Therefore, based on the results of this study, there is a greater probability of success using a sample from the edge of a blood stain spotted in FTA™ paper than any other location of the FTA™ card.
140

Image Processing and Super Resolution Methods for a Linear 3D Range Image Scanning Device for Forensic Imaging

Joshi, Abhishek Shriram 14 August 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / In the last few decades, forensic science has played a significant role in bringing criminals to justice. Shoe and tire track impressions found at the crime scene are important pieces of evidence since the marks and cracks on them can be uniquely tied to a person or vehicle respectively. We have designed a device that can generate a highly accurate 3-Dimensional (3D) map of an impression without disturbing the evidence. The device uses lasers to detect the changes in depth and hence it is crucial to accurately detect the position of the laser. Typically, the forensic applications require very high resolution images in order to be useful in prosecutions of criminals. Limitations of the hardware technology have led to the use of signal and image processing methods to achieve high resolution images. Super Resolution is the process of generating higher resolution images from multiple low resolution images using knowledge about the motion and the properties of the imaging geometry. This thesis presents methods for developing some of the image processing components of the 3D impression scanning device. In particular, the thesis describes the following two components: (i) methods to detect the laser stripes projected onto the impression surface in order to calculate the deformations of the laser stripes due to 3D surface shape being scanned, and (ii) methods to improve the resolution of the digitized color image of the impression by utilizing multiple overlapping low resolution images captured during the scanning process and super resolution techniques.

Page generated in 0.2884 seconds