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  • 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.
141

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.
142

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.
143

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.
144

Kartering van selfoontegnologie

Lochner, Hendrik Thomas 10 1900 (has links)
It is sincerely hoped that this work will motivate other researchers and in particular my colleagues to do further research in the field of cellphone technology, especially how it can be mapped to enable it to be utilised as evidence in our courts. This research aims to develop the mapping of cellphone technology as an aid in the investigation of crime. The mapping of cellphone technology refers to how cellphone technology can be utilised in crime investigation and in particular how a criminal can be placed at the scene of a crime, as a result of a cellphone call that was either made or received. To place the suspect at the scene of a crime as a result of a call made or received, cellphone records and technology of the relevant cellphone company, as well as present computer programmes can be utilised. Shortly, it can be said that a criminal can geographically be placed within a space some where on this earth. / Criminology / M.Tech. (Forensic Investigation)
145

Modus operandi as technique in suspect identification in burglary cases

Berning, J. M. S. P. 31 August 2008 (has links)
The research attempts to establish how modus operandi can be used to identify suspects in burglary cases. To conduct effective investigation, it is important for investigators to be familiar with the concept modus operandi, its elements, its influence and its values. To achieve the goals and objectives of the practice of modus operandi, investigators must know how to apply modus operandi, what the situational factors are during a criminal act, and how to use it as technique to identify suspects in burglary cases. The direction by implication and clarification of the crime situation is hardly possible without the determination of the identity of the perpetrator or suspect of a criminal act. The recognition of the modus operandi system as any form of evidence gathering is of outmost importance. / Criminology / M.Tech. (Forensic investigation)
146

Kriminologiese ontleding van die gebruik van forensiese kuns in die ondersteuning van slagoffers van geweldsmisdade in die Pretoria-area, Suid-Afrika

Visser, Henrico Pieter 02 1900 (has links)
Summaries in English and Afrikaans / This research explores the potential value for the application of the visual expressionistic arts, as well as the application of forensic art for the emancipation of victims of violent crime. Qualitative research methods are used in order to make certain assumptions and recommendations for the application of the forensic arts in the emancipation of traumatized victims. The research is based on the view that human behaviour is influenced by different internal and external contextual influences. The theoretical basis for the research is further supported by the grounding principals of the psycho-analytic, symbolic interactionistic and the phenomenological theoretical approaches. The potential for the application of the forensic arts during crisis intervention and trauma counselling as a therapeutic technique and a communication medium are investigated. The potential forensic value of the victims’ art for the criminal justice system is also explored during the research. / Die navorsing ondersoek die potensiele waarde vir die aanwending van die tradisionele visuele beeldende kunste asook die aanwending van die forensiese kunste vir die emansipasie van slagoffers van geweldsmisdaad. Kwalitatiewe navorsingsmetodes word tydens die navorsing gebruik ten einde sekere afleidings en aanbevelings te maak aangaande die aanwending van die forensiese kuns vir die emansipasie van getraumatiseerde misdaadslagoffers. Die navorsing word teoreties gebaseer op die beskouing van die mens wie se gedrag beinvloed word deur verskillende interne en eksterne kontekstuele invloede. Die teoretiese basis vir die navorsing word verder ondersteun deur die grondbeginsels van die psigo-analise, simboliese interaksionisme en die fenomenologiese teoretiese benaderings. Die potensiaal vir die aanwending van forensiese kuns as 'n terapeutiese tegniek en kommunikasiemedium tydens krisisingryping en berading word ondersoek. Die potensiele forensiese waarde van misdaadslagoffers se kuns in die regsplegingstelsel word ook in die navorsing ondersoek. / Criminology / M.A. (Criminology)
147

The use of body language (behaviour pattern recognition) in forensic interviewing

Naidoo, Shantell 02 1900 (has links)
With this study, the researcher wants to establish whether investigators are able to effectively interpret, report on, or pay cognisance to body language during interviews, and whether they are sufficiently trained therein. Knowledge of body language can provide the interviewer with vital clues during the interview process. Regardless of the availability of numerous literatures on nonverbal behaviour in interviewing, the application of this knowledge is lacking among investigators. An empirical research design and a qualitative research approach were used for this research. National and international literature sources were consulted, and the researcher conducted interviews with two experts, knowledgeable investigators and semi-structured interviews with detectives from the East London South African Police Service (SAPS) and forensic investigators from the Special Investigating Unit (SIU) in East London. The importance of the skill of interpreting body language during forensic interviewing was established. Evidently, many investigators do not apply their knowledge and skill to enhance the outcomes of a forensic interview. / Criminology and Security Science / M. Tech. (Forensic Investigation)
148

A critical analysis of the procedures followed in child rape cases in Mpumalanga Province

Boodhoo, Vinesh 02 1900 (has links)
This study reflects a critical analysis of the procedures followed in child rape cases in Mpumalanga Province and in the process to enhance investigative capabilities with sound detective development. Empirical research was conducted with a literature review, docket analysis and interviews as methods to obtain information where the following important aspects were addressed: an overview of the field of forensic investigation, the shortcomings with regard to child rape investigations and correct procedures for conducting child rape investigations formulated. The study found that generally rape cases were not properly investigated, correct procedures were not followed (biological/physical evidence was not readily identified nor correctly handled) and applicable directives pertaining to child rape investigations not complied with. Investigators had a narrow understanding of the concept forensic investigation. In child rape investigations it would be of more evidential value and reliable to collect physical evidence such as blood, semen, vaginal fluids and saliva as the child’s testimony at court might not be reliable, particularly when subjected to cross examination. Rape is both a contact crime as well as a psychologically motivated crime and both aspects of the trauma needs attention during the investigation process. Crimes against women and children are also a national concern, thus making child rape a priority crime for the South African Police Service. For any successful prosecution it is necessary that policy and correct procedures are not compromised but rather strictly adhered to. The Locard Principle in relation to physical evidence such as body fluids at the crime scene needs to be focussed on during the investigation process. The research suggests that the current standing operating procedures be amended to include the critical aspects of child rape investigation such as processing of the crime scene, the search for biological evidence as well as the packaging and preservation of biological evidence. / Police Practice / M. Tech. (Forensic Investigation)
149

The significance of video evidence analysis in the investigation of murder cases against the police

Kgamanyane, Ketsebae Israel 09 1900 (has links)
The researcher attempts to establish the significance of video evidence analysis in the investigation of murder cases against the police. The evidence obtained could be crucial and admissible in court and ultimately resulted in the successful prosecution of an accused person. In order for investigators to conduct an effective investigation, it is important that they become familiar with the application of video evidence, its purpose, benefits and shortfalls. In order to achieve the intended goals and objectives of video evidence, the investigators should know how to collect, package, process and analyse video evidence. The clarification and processing of the crime scene of video evidence as well as the identification of a suspect at the scene of crime is very much important and without video evidence it would be difficult to convict an accused person in a court of law. / Police Practice / M. Tech. (Forensic Investigation)
150

Modus operandi as technique in suspect identification in burglary cases

Berning, J. M. S. P. 31 August 2008 (has links)
The research attempts to establish how modus operandi can be used to identify suspects in burglary cases. To conduct effective investigation, it is important for investigators to be familiar with the concept modus operandi, its elements, its influence and its values. To achieve the goals and objectives of the practice of modus operandi, investigators must know how to apply modus operandi, what the situational factors are during a criminal act, and how to use it as technique to identify suspects in burglary cases. The direction by implication and clarification of the crime situation is hardly possible without the determination of the identity of the perpetrator or suspect of a criminal act. The recognition of the modus operandi system as any form of evidence gathering is of outmost importance. / Criminology and Security Science / M.Tech. (Forensic investigation)

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