Generally, biological samples are collected from crime scenes using swabbing, cutting, or taping techniques. However, these methods are limited in their abilities to recover diluted, masked, or otherwise invisible stains. Additionally, their targeted nature allows only a small portion of a larger stain to be collected at one time. In this study, a sterile wet-vacuum collection system was evaluated in its ability to collect small volume bloodstains from various substrates. Vacuuming was compared to swabbing and taping methods currently used in forensic analysis. Samples were collected from porous and nonporous surfaces; the efficacy of each collection method was evaluated with a colorimetric presumptive blood test. To evaluate each collection method, dilutions containing from 0.25 nl to 25 μl human blood were spotted on common substrate materials, allowed to dry, and recovered. For comparison to the novel method, single-swabbing and tape-lifting techniques were performed in this study to collect samples for presumptive testing. During wet vacuum collection, stains were saturated with sterile buffer and suction was applied to the surrounding area, accumulating buffer in a collection bottle. Collected buffer was then filtered through membranes to capture cellular material, which were then presumptively tested for the presence of blood. Testing was performed with Kastle-Meyer (phenolphthalein) reagents. Each sample was photographed under consistent conditions in order to determine signal intensity. It was shown that the wet-vacuuming technique is able to recover sufficient amounts of blood for presumptive testing from multiple substrates. This method was able to detect similar dilutions of blood as traditional techniques in samples collected from porous surfaces, but was less effective on a nonporous substrate. Presumptive test image analysis shows increased relative intensity in collections from textiles, such as denim, when using the wet-vacuum system. Considering the results of a contemporaneous DNA quantification study, it was shown that in instances where a very weak presumptive result is found, the wet-vacuum technique may be better able to collect genetic material for downstream processing than the traditional methods evaluated. This study demonstrates the potential of wet-vacuuming as a suitable alternative technique to collect adhered cellular material from substrates in forensic investigations.

Crime Scene Investigation is without a doubt one of the most important step in criminal proceeding, which allows us to gain a complete picture over events, that really happened. To helps us attain this knowledge, there are certain reflections of perpetrators actions in form of physical evidence, that needs to be found and professionally secured. The task of crime scene investigation team of the relevant department of the Police of the Czech Republic, which intervenes on the scene, is to examine the scene and to provide all the evidence that could help clarify the case. Procedure on the crime scene requires a perfect organization by the head of the crime scene investigation team, which puts high demands on expertise and practical experience of the lead investigator. This procedure is one of the most difficult in the entire criminal proceedings, because even small neglect od duties can have a fatal consequence. This thesis compiles a specific legal texts, that are designated to the students of the law faculties, and for the students of the Police academy of Czech republic, and also knowledge attain from practical guides and guidelines directly for the police officers in Czech republic and tries to create a set of law sources, that will not only compare them, but it will also include authors opinions....

This diploma thesis is devoted to the investigation methodology of murders. The main emphasis is given to the procedure of the police authority within the investigation of murders. Since this topic is very extensive and the methodology comprises of the great amount of activities, I dedicate this diploma thesis only to the selected areas thereof. The first chapter describes the specification of the crimes against life, in particular legal regulation and related aspects. I focused on the legal regulation in Czech law with respect to a crime of murder, homicide and murder of a new born by its mother. Only marginal attention is given to a crime of negligent manslaughter and a crime of assisting with suicide. The second chapter comprises of the statistics of the committed murders. I analyse the statistics of the numbers of murders committed within the European Union, the Czech Republic and the Ústí region. Another part of the thesis is theoretically orientated. I concentrate on the criminalistics characteristic of a murder and the fundamental aspects thereof - the mode of committing a crime, the personality of a murderer, the personality of a victim and a criminal motive. The following chapter forms the crucial part the diploma thesis in which I analyse typical investigation situations, in particular in...

in English The topic of the thesis is the " The Methodology of Investigation of Murders (selected issues)". The topic is too broad for the limited capacity of the dissertation. While writing the thesis, after the necessary theoretical introduction (which contains the definition of crimes against life, medical definition of death, etc.), I focused only on the initial stage of the investigation of the crime of murder. I specifically focused on the discovery of the body, on securing the crime scene, on autopsy and on the demarcation of investigative versions. Next stage of the investigation is only briefly summarized in the ninth chapter. The thesis is divided into ten chapters. The first chapter explains basic terms, especially murder, murder of a newborn baby by its mother and other crimes against life, such as manslaughter, negligent homicide and assistance to suicide. This chapter also includes medical definition of death, and a brief description of the post-mortem changes. The second chapter consists of brief statistics on the number of murders in the Czech Republic between the periods 2000 to 2012. It contains two graphs; the first graph shows the evolution of the total number of murders each year and their solving. The second graph divides murders according to the specific motives. The third...

Psychological Profiling of an Offender The purpose of the thesis is to describe and demystify the subject of offender profiling, also called criminal profiling or psychological profiling. Criminal profiling is one of key disciplines of forensic psychology which approximately in the last twenty years became recognized as a helpful investigative tool for resolving difficult criminal cases. The thesis is structured into four chapters, each one covering different aspect of criminal profiling. First chapter defines criminal profiling, its basic premises, formation and history, different approaches to profiling and possible uses of profiling. Second chapter focuses on practical use of criminal profiling. It covers criteria for using profiling in a particular criminal investigation, includes basic information about perpetrators and victims and shortly touches upon computer databases used in profiling. Third chapter covers the actual creation of profile of an unknown offender, from different sources suitable for gathering information to uncovering the offender's motivation and finally to the finished psychological profile. It also includes information about perpetrators of arson, rape and murder, as samples of serious offenses where offender profiling is often applied. Fourth chapter analyses the use of...

The thesis describes psychological profiling of an offender, which is a method used for investigating serious criminal acts. It was developer in the United States of America, particularly on the FBI ground, and is based on creating an image of probable unknown offender. The goal of the thesis is to provide readers with basic information about what is psychological profiling and how the process works. The paper is divided into five chapters. First, opening chapter is divided into three parts. In the first one, the reader can find information about the term psychological profiling, how it is defined and what is it for. Second part contains information about history of the method including some about the development in the Czech Republic. The third part describes offences suitable for profiling and those which are not. The second chapter is focused on creating the profile. First it describes the characteristic of the crime scene as basic information for the investigation, and then the typology of offenders is mentioned, directed at organized and disorganized typology. The end of this chapter is dedicated to the final look of the profile. In the third chapter some approaches to profiling are mentioned. These are the FBI model, named crime scene analysis, then profiling in Germany and Great Britain. This...

Offender profiling aims at generating information of an offender based upon the crime committed and the goal is to be an adjunct in the crime invesigation process. The aim of the study was to examine crime scene characteristics and corroborating evidence and their associations with offenders' interrogation behavior. Results from 207 analyzed police files indicated that reactive (impulsive) offenders confessed more often when there was technical evidence against them compared to instrumental (calculating) offenders. Reactive offenders also had more injuries. Injured reactive offenders were more inclined to deny, whereas injured instrumental offenders claimed amnesia more often. When comparing the confessions injured reactive offenders were more inclined to confess than injured instrumental offenders. There was also a strong tendency implying more confessions with witness reports. The findings point towards the practical usefulness of information of crime scene characteristics and corroborating evidence in the interrogation phase by better tailoring the interviewing strategy.

This research, situated at the intersection of sociology, science and technology studies and police studies, provides the first sociological account of Crime Scene Investigator (CSI) training in England and Wales. Focusing on the acquisition and everyday enactment of CSI expertise, this qualitative, ethnographic investigation asks (1) what are the roles, practices and expertise of the CSI and (2) how is the CSI’s expertise developed in training and enacted in everyday work. These questions are explored through participant observation at the main training centre for UK CSIs, observation at crime scenes, interviews with trainees during and after their training and visual methods. By unpicking the visible and invisible components of CSI work, I analyse how CSIs are trained to document crime scenes and explore the practices of transforming a potentially relevant object from these locations into artefacts that meet the requirements of courtroom scrutiny. I demonstrate how CSIs engage actively and reflexively with the requirements of different conceptions of objectivity and the changing demands placed on them. They continually and performatively negotiate and delimit multiple boundaries, from the very literal in demarcating a crime scene to claiming their position within the investigative hierarchy in each interaction. Unlike other discussions of boundary work, for the CSI this is iterative, requires constant effort and is embedded in their routine practice. Within police environments, the CSI has scope for such boundary work. In the courtroom, however, crime scene investigation is narrowly defined. This thesis develops our understanding of the CSI and crime scene investigation as a practice. It stresses the significance of taking this actor seriously in any account of forensic science and investigative practices. By viewing the CSI as simply an evidence collector, or not considering her work at all, the expertise and pivotal role of this actor in the meaningful and efficient use of science in policing is blackboxed. My detailed qualitative analysis of the CSI’s role, work and specialist expertise contributes a necessary account of a key actor in the police and criminal justice system.

Bloodstain Pattern Analysis is a rapidly growing area of research in the forensic science field. It is not uncommon for blood to be present on surfaces such as clothing, furniture, carpet, and more, during the commission of a crime. . Research of how blood interacts with different porous surfaces, such as textiles and fabrics, is relatively unexplored in the field of forensic science. Prior to a bloodshed event in which blood may be deposited onto clothing, the fabric may have been laundered in a variety of ways. In this research, swatches of a 100% nylon, water resistant fabric were subjected to seventeen different laundering and soiling processes. The laundering products used included Tide® Liquid Laundry Detergent, Downy® Fabric Softener, Downy® Unstoppables In-Wash Scent Boosters, Bounce® Dryer Sheets, Clorox® Zero Splash Bleach Packs, and OxiClean™ Max Force Laundry Stain Remover. Soiling included wearing swatches of fabric and leaving them in direct sunlight. Whole human blood was inverted, vortexed, then transferred using a disposable transfer pipette. The sample was held 36 in./3 ft. above each sample at a 90-degree angle, using an apparatus made from a flat edge and a protractor to ensure consistency. Blood drops were deposited onto each swatch of fabric, photographed, and microscopically examined. The drip stains were measured and characteristics of the blood, fabric, and the interaction of the two were recorded. Results showed some trends, such as an increased breakdown of fabric structure when bleach was used, and an increase in wicking when treated with scent boosters. Overall, the results were varied in all comparisons.

This exploratory research is the first one among occupational information seeking behavior studies that focuses on information seeking behaviors of the crime scene investigators. The data used in this dissertation were gathered via a self-administrated survey instrument from 29 cities in Turkey. Findings obtained from the data analyses show that there is a strongly positive relationship between the experience of the crime scene investigators and the use of personal knowledge and experience as a primary information source (experience is operationalized with age, service years in policing, and service years in crime scene investigation units). The findings also suggest that increasing of the level of education is negatively related to relying on immediate colleagues as an information source among the crime scene investigators. These findings are consistent with related literature and theory. The data analysis shows that crime scene investigators work in cities with higher population rates have more complaint scores than those who work in cities with lower population rates across Turkey. The findings from the data analysis may suggest valuable implications to defeat the barriers between crime scene investigators and information sources. The researcher drew a proposed theoretical framework of an information behavior concept in the context of crime scene investigation that may help those who are interested in the phenomenon and its applications to other contexts.