Since its first use in criminal investigations in 1987, DNA profiling has become the new gold standard for investigations and prosecutions. Academics, politicians and law enforcement officials have presented DNA evidence as a ??scientific hero?? that is capable of solving crimes and preventing miscarriages of justice. However, in spite of this reputation, few studies have explored the impact of this technology on criminal justice practitioners, or on the process of investigating and processing criminal offences. This dissertation provides a comparative study of the use of DNA profiling in two jurisdictions: New South Wales (NSW) in Australia and the Thames Valley in the United Kingdom (UK). Interviews canvassed the perspectives and experiences of police officers, scene of crime officers (SOCOs), forensic scientists, criminal lawyers, and judicial officers from these areas. These interviews were analysed in conjunction with appeal judgments and police statistics to reveal how DNA evidence has been used in the NSW and Thames Valley. The research presented in this dissertation indicates that DNA profiling is having a number of far-reaching effects on both criminal justice systems and is seen as a reliable forensic tool by criminal justice practitioners. Practitioners routinely use DNA evidence throughout the various stages of the criminal justice process and are actively changing their practices to utilise the technology more effectively. One of the main impacts of the introduction of DNA evidence into criminal investigations has been the need to provide substantial resources and infrastructure for the collection, analysis, and storage of samples. Both jurisdictions encountered a number of problems because they provided insufficient resources to effectively use DNA profiling. This study also offers insight into how criminal justice practitioners perceive the dangers of using DNA evidence and how miscarriages of justice can occur. Finally, through an analysis of the combined experiences of criminal justice practitioners, this dissertation challenges the widespread acceptance and routine use of forensic DNA profiling. It further suggests that it is now time to re-consider current practices in relation to how resources are devoted to the technology, and how criminal justice practitioners are using the technology.

Since its first use in criminal investigations in 1987, DNA profiling has become the new gold standard for investigations and prosecutions. Academics, politicians and law enforcement officials have presented DNA evidence as a ??scientific hero?? that is capable of solving crimes and preventing miscarriages of justice. However, in spite of this reputation, few studies have explored the impact of this technology on criminal justice practitioners, or on the process of investigating and processing criminal offences. This dissertation provides a comparative study of the use of DNA profiling in two jurisdictions: New South Wales (NSW) in Australia and the Thames Valley in the United Kingdom (UK). Interviews canvassed the perspectives and experiences of police officers, scene of crime officers (SOCOs), forensic scientists, criminal lawyers, and judicial officers from these areas. These interviews were analysed in conjunction with appeal judgments and police statistics to reveal how DNA evidence has been used in the NSW and Thames Valley. The research presented in this dissertation indicates that DNA profiling is having a number of far-reaching effects on both criminal justice systems and is seen as a reliable forensic tool by criminal justice practitioners. Practitioners routinely use DNA evidence throughout the various stages of the criminal justice process and are actively changing their practices to utilise the technology more effectively. One of the main impacts of the introduction of DNA evidence into criminal investigations has been the need to provide substantial resources and infrastructure for the collection, analysis, and storage of samples. Both jurisdictions encountered a number of problems because they provided insufficient resources to effectively use DNA profiling. This study also offers insight into how criminal justice practitioners perceive the dangers of using DNA evidence and how miscarriages of justice can occur. Finally, through an analysis of the combined experiences of criminal justice practitioners, this dissertation challenges the widespread acceptance and routine use of forensic DNA profiling. It further suggests that it is now time to re-consider current practices in relation to how resources are devoted to the technology, and how criminal justice practitioners are using the technology.

Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: Benjamin D. Fleury-Steiner, Dept. of Sociology & Criminal Justice. Includes bibliographical references.

The use of circumstantial evidence in proving the guilt of defendants in high profile murder cases has evolved. There have been several cases in particular that exemplify this. This thesis aims to descri?e the persuasiveness of circumstantial evidence in proving the guilt of a defendant. It also aims to demonstrate that the defendants' actions, behaviors and appearances, which were once only commented upon by the media and public, have become admissible and convincing evidence because they indicate a consciousness of guilt. This thesis will highlight the aspects of the media's role in covering high profile murder cases and how this involvement impacted the cases. In order to show how the circumstantial evidence, including the defendant's behavior was sufficient to warrant a conviction at trial, the bulk of this thesis will examine various highly publicized cases and the evidence presented. This thesis will also discuss how the media has allowed high profile defendants to be tried in part, by public opinion. By examining the dynamics of several high profile murder cases that were prosecuted based on circumstantial evidence, this thesis will show the evolution of such evidence and its effectiveness in our present day courts.

No description available.

L’analyse et l’interprétation d’´echantillons constitu´es de mélanges d’ADN de plusieurs individus est un défi majeur en science forensique. Lorsqu’un expert de la police scientifique a affaire à un mélange d’ADN il doit répondre à deux questions: d’abord, “combien de contributeurs y a-t-il dans ce mélange ?”et puis, “quels sont les génotypes des individus impliqués ?” Le typage seul de cet ADN ne permet pas toujours de r´epondre `a ces questions. En effet leproblème est posé d`es lors que plus de deux allèles sont observées à un locus donné, plusieurscombinaisons génotypiques sont alors `a envisager et il est impossible de déterminer avec certitudele nombre d’individus qui ont contribué au m´elange. De plus, la présence d’anomalies liées àl’analyse de marqueurs g´en´etiques, comme la contamination ou la perte d’all`eles (“drop-out”),peut davantage compliquer l’analyse.Les nombreux d´eveloppements statistiques d´edi´es `a ces probl´ematiques n’ont pas eu le succ`esescompt´e dans la communaut´e forensique, essentiellement, parce que ces m´ethodes n’ont pas ´et´evalid´ees. Or sans cette validation, les experts de la police scientifique ne peuvent exploiter cesm´ethodes sur des m´elanges issus d’affaires en cours d’investigation.Avant d’ˆetre valid´ees, ces m´ethodes doivent passer par une rigoureuse ´etape d’´evaluation.Cette derni`ere soul`eve deux questions: d’abord, la question de la m´ethodologie `a adopter, puis,celle des outils `a d´eployer. Dans cette th`ese, nous tentons de r´epondre aux deux questions.D’abord, nous menons des ´etudes d’´evaluation sur des m´ethodes d´edi´ees `a deux questions cl´es: i)l’estimation du nombre de contributeurs `a un m´elange d’ADN et ii) l’estimation des probabilit´esde “drop-out”. En second lieu, nous proposons un logiciel “open-source” qui offre un certainnombre de fonctionnalit´es permettant de faciliter l’´evaluation de m´ethodes statistiques d´edi´eesaux m´elanges d’ADN.Cette thèse a pour but d’apporter une r´eponse concr`ete aux experts de la police scientifiqueen leur fournissant `a la fois une d´emarche m´ethodologique pour l’´evaluation de m´ethodes, et lapossibilit´e d’analyser la sensibilit´e de leurs r´esultats au travers d’un outil informatique en libreacc`es. / Analysis of forensic DNA mixtures recovered from crime scenes is one of the most challengingtasks in forensic science. DNA mixture raise two main questions: “how many contributors arethere” and “what are the genotypes of the contributing individuals?” The genetic characterizationalone of such samples does not always answer these questions. In fact, whenever more thantwo alleles are observed at a given locus, several distinct genotypic combinations are plausiblefor the unknown contributors to the sample, and it is not possible to determine the number ofthese contributors with absolute certainty. Besides, the presence of anomalies related to DNAtyping techniques, such as contamination or allele loss (drop-out), can further complicate theanalysis.Numerous statistical developments facilitating DNA mixtures interpretation were proposed,but they did not receive the expected success in the forensic community. The main explanationfor this is that these methods are not validated for forensic casework.In order to achieve this validation criterion, the methods must undergo a rigorous evaluationstep. The latter raises two questions: i) how methods should be evaluated? and ii) whattools can be used to conduct evaluation studies? In this thesis we attempt to answer bothquestions. First, we evaluate methods dedicated to two key issues, the estimation of the numberof contributors to DNA mixtures and the estimation of drop-out probabilities. Second, wepropose an “open-source” software that offers a number of functionalities dedicated to facilitatingmethod evaluation through the simulation of data commonly encountered in forensic settings.This thesis aims to provide a concrete answer to the issues raised by forensic DNA mixtures,by providing a methodology for method evaluation and by offering necessary tools to enablemethod evaluation.