Spatial and temporal influences on bacterial profiling of forensic soil samples

Bacterial content may be helpful in differentiating forensic soil samples; however, the effectiveness of bacterial profiling depends on several factors, including uniqueness among different habitat types, the level of heterogeneity within a habitat, and changes in bacterial communities over time. To examine these, soils from five diverse habitats were tested over a 1 year period using terminal restriction fragment length polymorphism (TRFLP) analysis. Soil samples were collected at central locations monthly, and 10 feet in cardinal directions quarterly. Similarity indices were found to be least related among habitats, while the greatest bacterial similarities existed among collection locations within a habitat. Temporally, however, bacterial content varied considerably, and there was substantial overlap in similarity indices among habitats during different parts of the year. Taken together, the results indicate that while bacterial DNA profiling may be useful for forensic soil analysis, certain variables, particularly time, must be considered.     

Post-traumatic meningitis: histomorphological findings, postmortem microbiology and forensic implications

Infections of the leptomeninges with the infectious agent gaining access to the intracranial compartment by traumatic means are termed post-traumatic. In cases with fatal outcome, the manner of death has to be classified as non-natural. Six cases of post-traumatic meningitis as the cause of death from the archives of the Institute of Legal Medicine in Hamburg, Germany with histological and microbiological investigations are presented. There were all males, age varying between 24 and 90 years (mean 58 years); range of the interval between original trauma and beginning of symptoms was 2 days up to 8 years; in 50% of the cases meningeal swabs yielded Streptococcus pneumoniae. Findings concerning origin and mechanism of post-traumatic meningitis as well as microbiological studies are compared with selected cases from the literature.     

The influence of site of collection on postmortem morphine concentrations in heroin overdose victims

When assaying for postmortem morphine concentration, significant site sampling variability exists between central and peripheral sampling sites and even within sampling regions of the body. To study the variation, 76 suspected heroin overdoses were identified. Each had femoral artery (FA) and vein (FV), left and right ventricle and pooled heart blood samples obtained at autopsy. Forty-four tested positive for morphine. Morphine concentrations were determined by gas chromatography/mass spectrometry, with sampling site differences reported as log-transformed ratios and compared by signed rank test.The mean FA to FV ratio for total morphine was 1.2 (range 0-4.5). The ratio for left heart to right heart total morphine was 1.1 (range 0.4-3.2). Left ventricular to FV total morphine ratio was 2.0 (range 0.6-6.9). In these opioid overdose deaths, FA and FV morphine concentrations are usually similar, although up to 4.5-fold differences were noted. Centrally obtained morphine concentrations are on average twice as high compared with peripheral morphine concentrations. Left and right ventricular morphine concentrations were usually similar, although up to 3.2-fold differences were noted (left side higher).     

分子生物学指标用于推断机械性窒息死亡的研究进展

体表损伤轻微或无损伤的机械性窒息死亡是法医学鉴定的难点之一。由于缺少病理形态学特异性变化特征,较难与部分存在缺氧过程的其他致死原因相鉴别。近年来,将具有相关性、特异性分子生物学指标用于推断机械性窒息死亡,已成为研究热点。本文就上述专题中法医学最新研究文献进行复习综述,以期为机械性窒息死亡的研究提供新思路。     

我国法庭科学实验室管理中的问题与对策

本文从管理体制和运行机制两个层面对国内外法庭科学实验室的管理工作进行了综述，深入探讨并分析了我国现有实验室管理中存在的问题，并有针对性的提出了政策建议。     

Freshwater diatom transfer to clothing: Spatial and temporal influences on trace evidence in forensic reconstructions

Environmental indicators are increasingly sought and analysed in a range of forensic reconstructions. Although the majority of casework and research studies are concerned with the criminal investigation of terrestrial habitats (soils, sediments, plants etc.), freshwater environments are also frequently encountered as crime scenes. As such, microalgae, particularly diatoms, may provide useful circumstantial trace evidence following their transfer to a victim or perpetrator. Diatom analysis is a relatively underused technique in forensic ecology, although an increased empirical research focus is beginning to recognise the evidential value of a transferred assemblage. This study aimed to examine three of the spatial and temporal variables known to influence the extent of an initial transfer of trace particulates, within the context of freshwater diatoms to clothing. A series of experiments were designed to consider the impact of recipient surface characteristics (clothing type), source environment conditions (seasonality), and morphological (type of diatom) variability, on the total number (no. per cm²) and species richness (total no. sp.) of an evidential diatom sample recovered from clothing. Nine commonly used clothing materials were immersed in a freshwater river at three times of year – the early and late spring and in the winter. Diatoms were recovered using a H₂O₂ extraction technique and examined microscopically. The results demonstrated that diatom transfer to clothing varies significantly, with a greater abundance and a higher species richness transferred to coarse woven surfaces including acrylic, linen, and viscose. Significantly fewer diatoms were transferred to clothing in the winter, in line with seasonal fluctuations in the source environment diatom community. Furthermore, variation in the relative abundance of particular diatom species was identified between clothing types, provisionally suggesting that morphological characteristics may also support or limit the transfer of material. These findings highlight that, although clothing may offer a valuable repository of freshwater diatom trace evidence, the interpretation of evidential material should be approached within an exclusionary framework. Thus, empirical data has been generated to develop evidence bases within forensic ecology, demonstrating some of the spatial and temporal factors which may contribute to or limit the transfer of evidence.     

The future of forensic and crime scene science. Part II. A UK perspective on forensic science education

This paper builds on the views presented by the author at 'The Future of Forensic and Crime Scene Science Conference'. Forensic science has become an increasingly prominent area of science within the last 10 years. This increasing prominence together with popularity in the subject has seen the number of undergraduate students studying forensic science related courses at UK Universities increase rapidly in just 5 years and there are no short term signs of this trend reducing. In 2005, there were 450 courses with forensic in the title offered by higher education institutes. Although the forensic community has expressed its concern that job prospects for these students wishing to pursue careers as forensic scientists will be limited numbers of students undertaking science courses have still increased. The increase in students studying forensic science comes in an era of decreasing science numbers in higher education with the potential to produce high calibre science graduates with sought after skills in critical thinking, analysis, interpretation and communication. Technology has continued to advance at a similar pace providing those responsible for managing crime with a need and opportunity to identify and predict new and future applications of science and technology; not just in reducing and detecting crime but also in predicting how technology will be used by criminals in the future. There is therefore a need for forensic science users, providers and educators to identify the knowledge and skills required by forensic scientists and crime investigators of the future to ensure that technology continues to be used and applied to its full advantage. This provides universities an opportunity to contribute to the development of both the practice and practitioners of forensic science. This paper outlines the current issues facing universities in relation to forensic science and identifies their future role in providing high quality relevant courses for future forensic practitioners; developing current forensic practitioners through their participation in applied research, short courses, conferences and qualifications linked to professional practice; and supporting and developing the practice of forensic and crime scene science, through the identification, engagement and dissemination of pure and applied research.     

脑血管造影在法医学尸体检验中的应用

脑血管造影作为诊断脑血管疾病的"金标准",目前已经广泛地应用于临床医疗活动中,并积累了丰富的理论和实践资料,是趋于成熟的技术方法。由于因脑血管疾病引发的法医学鉴定案件较为多见,故该技术近年开始应用于法医学,显示出在法医学实践中独特而重要的应用价值。本文对脑血管造影术在法医学中的应用价值进行综述,内容包括辅助定位血管病变或损伤部位、明确出血性质、指导尸体解剖与脑组织病理取材等,并在此基础上展望了该技术在法医学中的应用前景。     

The contribution of forensic science to crime analysis and investigation: forensic intelligence

The debate in forensic science concentrates on issues such as standardisation, accreditation and de-contextualisation, in a legal and economical context, in order to ensure the scientific objectivity and efficiency that must guide the process of collecting, analysing, interpreting and reporting forensic evidence. At the same time, it is recognised that forensic case data is still poorly integrated into the investigation and the crime analysis process, despite evidence of its great potential in various situations and studies. A change of attitude is needed in order to accept an extended role for forensic science that goes beyond the production of evidence for the court. To stimulate and guide this development, a long-term intensive modelling activity of the investigative and crime analysis process that crosses the boundaries of different disciplines has been initiated. A framework that fully integrates forensic case data shows through examples the capital accumulated that may be put to use systematically.     

法庭科学实验室认可工作发展状况与启示

本文通过对国内外,特别是对先进国家法庭科学实验室认可工作发展变化情况的介绍,分析我国认可工作中存在的不足,并提出改进意见。     

DNA typing and forensic science

With new typing techniques forensic scientists can characterise individuals at the fundamental level of their DNA. Variation between individuals at this level can be used to discriminate between them. Why this is so and how it is achieved is described in relatively simple terms for legal and medical practitioners who have no formal training in genetics.     

The future of forensic and crime scene science. Part I. A UK forensic science user and provider perspective

This paper presents an overview of the views expressed by UK forensic science users and providers during the Centre for Forensic Investigation's 1 day conference 'The Future of Forensic and Crime Scene Science' and is set in the context of the changing national agenda and likely advances in current and future technology. It begins by examining the success of the Home Office DNA Expansion Programme and future demands of the Criminal Justice System, highlighting the changing use of forensic science both at the crime scene and within the forensic process itself. In particular, the use of forensic science at the early stages of an investigation to provide intelligence and support the decision making process is discussed together with the need to adopt a partnership approach to tackling crime and its causes. Key system and technological drivers for performance improvement and change are identified and the likely timescales and implications of their introduction are discussed. Finally, the Home Office plans to build on the success of the DNA Expansion Programme, through the introduction of the proposed Home Office Forensic Integration Strategy, are explored and the paper concludes by highlighting the benefits, implications and issues arising from the changing and developing use of forensic science.     

The effect of lethal electrical shock on postmortem serum myoglobin concentrations

Postmortem serum myoglobin concentrations in blood from the femoral vein (peripheral withdrawal) and the heart (central withdrawal) of nine electrical fatalities were compared with those of 74 individuals who had died of other causes. Independent of the cause of death or topographical site, serum myoglobin concentrations rose dramatically with the passage of postmortem time (maximum concentrations in the control group: 975,100 micrograms/l). In 59% of the total sample (electrical fatalities plus controls), serum myoglobin concentrations were higher in the central blood, in the other 41% the concentrations were higher in the peripheral blood. The differences in concentrations between the peripheral and the central withdrawal area correlated with neither the postmortem interval nor the cause of death. Up to the second day postmortem there was a statistically significant difference in serum myoglobin concentrations between electrical fatalities and controls. The individual values within each group, however, varied widely and overlapped between groups. Controls who had also suffered muscle injury (polytrauma, myocardial infarction) did not have significantly higher serum myoglobin concentrations than controls without muscle injury. Myoglobin concentrations appear to be greatly influenced by the extent and duration of the muscle cramps induced by the electrical current. Correct interpretation of serum myoglobin concentrations depends on the knowledge of events surrounding the lethal electrical shock. Postmortem determination of serum myoglobin concentrations alone is, therefore, not sufficient to establish intravital exposure to electrical current and can aid the diagnosis only in special cases.     

The forensic science use of reflective ultraviolet photography

Reflective ultraviolet photography has many forensic science applications particularly in child abuse, rape, homicide, and bite mark cases. The potential of this relatively simple and inexpensive procedure has not been fully explored. The procedure for its use in bite mark cases is presented.     

微流控芯片技术在刑事科学中的应用

目的　阐述微流控芯片技术在法庭科学上的应用。方法　研究国内外已报道的微流控芯片快速、灵敏、高通量技术的有关资料。结果　提出在法医DNA检验、毒剂和毒物检测、麻醉剂或毒品检测、爆炸残留物检测等刑事技术上的应用前景。结论　从刑事侦查的角度看出该技术的巨大发展潜力