Use of fecal material to associate a suspect with a crime scene: report of two cases

Fecal matter analyses were applied to two cases: a homicide and a robbery. Scrapings of fecal matter removed from samples of clothing obtained from a homicide suspect were examined for their plant cell and cell fragment content and compared with fecal matter from a rape-homicide victim and scrapings from her clothing. Scrapings were hydrated and examined microscopically. Types of food plants were identified from the observed cells by comparison with known food plants. A similar analysis was conducted on the clothing of a robbery suspect and compared with fecal material left at the crime scene. The results showed that, respectively in the two cases, the reference samples were remarkably similar, if not identical, to those from the suspects' clothing.     

Persistent lipsticks and their lip prints: new hidden evidence at the crime scene

Latent lip print test results produced by permanent lipsticks are presented in this work. This cosmetic product, contrary to conventional lipsticks, does not leave visible prints and can thus be overlooked at the crime scene. As print vehicles the study used ceramics, glass, cotton fabric and paper. Lip prints were left to dwell for different periods and were later developed using aluminum powder, cobalt oxide powder and magnetic powder. The results show that identifiable lip prints can be obtained up to 30 days after being produced.     

关于恐怖主义犯罪心理和行为特点的初步研究

恐怖主义犯罪作为由某些组织或国家在恐怖主义理念支配下,通过暴力或其他危险方法造成社会恐怖,以实现其政治、宗教或其他意识形态目的的犯罪行为,是一种新的犯罪样态。这种犯罪往往具有较为独特的认知、情感特点和意志品质,也具有较为独特的行为特点。为更好的打击、预防这种犯罪。应加强其心理和行为特点的研究。     

Decision support for using mobile Rapid DNA analysis at the crime scene

Mobile Rapid DNA technology is close to being incorporated into crime scene investigations, with the potential to identify a perpetrator within hours. However, the use of these techniques entails the risk of losing the sample and potential evidence, because the device not only consumes the inserted sample, it is also is less sensitive than traditional technologies used in forensic laboratories. Scene of Crime Officers (SoCOs) therefore will face a ‘time/success rate trade-off’ issue when making a decision to apply this technology.In this study we designed and experimentally tested a Decision Support System (DSS) for the use of Rapid DNA technologies based on Rational Decision Theory (RDT). In a vignette study, where SoCOs had to decide on the use of a Rapid DNA analysis device, participating SoCOs were assigned to either the control group (making decisions under standard conditions), the Success Rate (SR) group (making decisions with additional information on DNA success rates of traces), or the DSS group (making decisions supported by introduction to RDT, including information on DNA success rates of traces).This study provides positive evidence that a systematic approach for decision-making on using Rapid DNA analysis assists SoCOs in the decision to use the rapid device. The results demonstrated that participants using a DSS made different and more transparent decisions on the use of Rapid DNA analysis when different case characteristics were explicitly considered. In the DSS group the decision to apply Rapid DNA analysis was influenced by the factors “time pressure” and “trace characteristics” like DNA success rates. In the SR group, the decisions depended solely on the trace characteristics and in the control group the decisions did not show any systematic differences on crime type or trace characteristic.Guiding complex decisions on the use of Rapid DNA analyses with a DSS could be an important step towards the use of these devices at the crime scene.     

Linking arson incidents on the basis of crime scene behavior

The present study investigated the possibility of statistically linking arson cases based on consistency of behaviors from one crime scente to another. Serial and spree arson cases were studied to differentiate underlying themes and to link cases committed by the same offender. The material consisted of 248 arson cases which formed 42 series of arsons. A content analysis using 45 dichotomous variables was carried out and principal compnents (PCA) analysis was performed to identify underlying themes. Summary scores reflecting the themes were calculated. Linking effectiveness was tested with a discriminant analysis using the summary scores. The PCA analysis was successful and underlying themes which were in accordance with previous studies could be identified. Six factors were retained, in the PCA. The linking of the arson cases was possible to a satisfactory level: 33% of the cases could be correctly linked and for over 50% of the cases, the series they actually belonged to was among the ten series identified as most probable on the basis of the linking analysis. From a practical point of view, the results could be used as a basis for developing support systems for police investigations of arson. This research was financially supported by the Finnish Ministry of Interior and by Grant 54456 from the Academy of Finland.     

基于游戏引擎的犯罪现场仿真研究

本文介绍了目前主流的可视化开发工具,结合公安实际并利用UDK（Unreal Development Kit）功能齐全,使用方便的特点,实现了犯罪现场三维重建,探讨了仿真流程、场景管理、材质及模型导入等关键问题。通过对案件模拟仿真的应用示例,将视景仿真技术与刑事科学技术紧密结合,方便了办案人员多角度观察现场、分析犯罪行为,提高了工作效率及判断的准确性,为现场勘察和重建中的技术难题寻求了解决方案。     

Identifying the scene of a crime through pollen analysis

The forensic analysis of pollen involves the comparison of crime scene and reference pollen samples. Successful matches are frequently used to solve time- or location-related crimes. Despite its prospects in criminal investigation, forensic palynology is still underused in casework due to inherent shortcomings such as its limited evidential weighting, scarcity of skilled palynologists dedicated to forensic casework and the laborious nature of analytical procedures. To address these challenges, the current state-of-the-art in forensic palynology is transiting from the traditional light microscopic methods that dominated the early days of palynology to more contemporary approaches like Raman spectroscopy, stable isotope analysis and DNA metabarcoding. The major challenges of these methods, however, include a lack of optimisation to forensic expectations and the unavailability of robust databases to permit accurate data interpretation, and quests to resolve these problems constitute the theme of current research. While reiterating the usefulness of pollen analysis in criminal investigation, this report recommends orthogonal testing as a way of improving the evidential weighting of forensic palynology.     

Real-time forensic DNA analysis at a crime scene using a portable microchip analyzer

An integrated lab-on-a-chip system has been developed and successfully utilized for real-time forensic short tandem repeat (STR) analysis. The microdevice comprises a 160-nL polymerase chain reaction reactor with an on-chip heater and a temperature sensor for thermal cycling, microvalves for fluidic manipulation, a co-injector for sizing standard injection, and a 7-cm-long separation channel for capillary electrophoretic analysis. A 9-plex autosomal STR typing system consisting of amelogenin and eight combined DNA index system (CODIS) core STR loci has been constructed and optimized for this real-time human identification study. Reproducible STR profiles of control DNA samples are obtained in 2 h and 30 min with ≤0.8 bp allele typing accuracy. The minimal amount of DNA required for a complete DNA profile is 100 copies. To critically evaluate the capabilities of our portable microsystem as well as its compatibility with crime scene investigation processes, real-time STR analyses were carried out at a mock crime scene prepared by the Palm Beach County Sheriff's Office (PBSO). Blood stain sample collection, DNA extraction, and STR analyses on the portable microsystem were conducted in the field, and a successful “mock” CODIS hit was generated on the suspect's sample within 6 h. This demonstration of on-site STR analysis establishes the feasibility of real-time DNA typing to identify the contributor of probative biological evidence at a crime scene and for real-time human identification.     

假说在现场勘查中的应用

综述了假说的特征和演化过程。通过案例论述假说作为逻辑推理方法之一在现场勘查中应用于死亡方式和伪装现场等的推断常起到事半功倍的效果。从一个侧面说明,刑事技术人员的专业技术固然重要,但严密的逻辑思维同样不可缺。     

法医现场勘查学初析

法医现场勘查是公安法医检案的一个组成部分,与痕迹现场勘查各有侧重。本文通过室内、野外、运动空间三类现场初步分析了法医现场勘查的要点。     

The place of a forensic archaeologist at a crime scene involving a buried body

This paper examines the place that forensic archaeologists should hold at scenes of crime where a body has been buried. The forensic archaeologist is rapidly becoming a key player whose specialty should be explained, and role defined. A high level of interaction between the forensic archaeologist and other personnel implies good communications skills as well as a precarious mix of receiving orders, assistance and advice as well as giving directions to other staff. The extent to which each of these should be applied will be discussed as well as underlying the absolute need for forensic archaeologist to attend these types of scenes.     

使用数字虚拟现实技术记录刑事现场

试图对使用数码相机,图像处理软件和计算机虚拟现实技术来记录刑事现场进行探讨。     

Evaluation of iodine-benzoflavone and ruthenium tetroxide spray reagents for the detection of latent fingermarks at the crime scene

The performance of two spray reagents, iodine-benzoflavone and ruthenium tetroxide (RTX), was evaluated and compared with the conventional technique currently used at the crime scene, that is, powdering. Neither the spray techniques nor powdering were shown to be suitable for all surfaces and ages of marks tested. On some surfaces such as glass and treated wood, powdering was still the superior technique, whereas the spray techniques produced better development on wallpaper, vinyl, and brick. Sequencing work showed that RTX was incompatible with powdering and cyanoacrylate (with a rhodamine 6G stain). Iodine-benzoflavone can be used successfully either before or after powdering in a sequence; however, it was incompatible with cyanoacrylate. Two non-CFC formulations of iodine-benzoflavone using HFC4310mee and HFE7100 solvents were tested and shown not to be as effective as the original Arklone (CFC-113) formulation; however, the HFC4310mee solvent is recommended as the most suitable replacement solvent. Due to the expense of the commercial RTX spray, attempts at formulating a more cost-effective version were also carried out. A formulation was developed that gave comparable development to the commercial version but at a much cheaper cost, and with a shelf life of up to two months. Recommendations are presented for which techniques are suitable for different surfaces and ages of marks. Powdering was shown to be the best technique on all ages of marks tested on treated wood, glass, and also on marks aged three days and older on paint. Iodine-benzoflavone was the best technique on wallpaper, vinyl, brick, and raw wood. RTX was the best detection technique for fresh marks and marks aged up to one day on wallpaper and paint.     

Evidence of DNA from epithelial cells of the hand of the suspect found on the tool of the crime

A young woman was found unconscious in her flat strangulated with a children's scarf and was at first thought to be dead. The victim survived but is disabled for life. Neither bloodstaines nor sperm were found at the scene. Swebs of fleece were prepared from two fingers of a one-way glove which were found at the scene and from each end of the scarf in order to find some epithelial cells from the criminal. DNA was extracted and amplified by the polymerase-chain-reaction (PCR). The DNA-profile of the victim as well as that of the suspected apart living husband were found in these mixed stains. The suspect was severely incriminated by these findings and other evidence. Consequently the court convicted him to eleven years of inprisonment because of attempted manslaughter.     

犯罪现场勘验中法医的职业安全

因鉴定体制特点,国内法医除鉴定工作外,还需进行犯罪现场勘验工作。在此过程中,可能面对很多风险,受伤和中毒等事件时有发生。然而,国内对现场勘验工作的防护只有少量规定,且内容不够详尽。本文对法医在现场勘验中的职业健康现状进行了分析,并将危害因素分为人、物、环境和管理四类进行论述。最后,从组织和技术两方面提出了具体防范措施。     

有机爆炸物的现场非介入性检测——顶空固相微萃取一真空气相色谱质谱法

本文考察了顶空固相微萃取在有机爆炸物现场非介入性检测中的适用性。由固相萃取（SPME）纤维头吸附的有机爆炸物用真空气相色谱一质谱联用仪进行检测。该方法所需的洗脱温度低,色谱分离时间短。SPME适用于提取蒸汽压不低于2．4,6-三硝基甲苯（TNT）的挥发性和半挥发性有机爆炸物,如较易挥发且不稳定的化合物三过氧化三丙酮（TATP）的非介入性检测就可以应用该方法。本研究使用静态顶空,尽可能地减少顶空体积,实现了较高的灵敏度。在现场,SPME方法的灵敏度受环境温度的影响较大：由于样品的蒸汽压未达到平衡,在固定顶空体积和萃取时间的条件下,SPME纤维头萃取的样品总量随温度的提高而增加。在有合适容器的情况下SPME纤维头上萃取的样品在取样3天后仍然能顺利检测。     

刑侦部门现场勘查率低的原因与对策

现场勘查是一项时间紧、任务重、头绪繁多,专业性强的侦查活动,而现场勘查工作的好坏、质量的高低,直接影响到案件的侦破、诉讼与串、并案工作。据成都警方统计,2003年成都市刑事案件现场勘查率仅为28%,经笔者的调查了解,相当的省、市、区公安机关的现埸勘查率大体与以上数据相同。为什么近些年现埸勘查率如此之低?需要采取什么样的措施来强化现场勘查工作乃至于侦查破案工作?笔者试图对现场勘查率低的成因进行分析,并在此基础上提出相应对策。     

Nature and place of crime scene management within forensic sciences

This short paper presents the preliminary results of a recent study aimed at appreciating the relevant parameters required to qualify forensic science as a science through an epistemological analysis. The reader is invited to reflect upon references within a historical and logical framework which assert that forensic science is based upon two fundamental principles (those of Locard and Kirk). The basis of the assertion that forensic science is indeed a science should be appreciated not only on one epistemological criteria (as Popper's falsification raised by the Daubert hearing was), but also on the logical frameworks used by the individuals involved (investigator, expert witness and trier of fact) from the crime scene examination to the final interpretation of the evidence. Hence, it can be argued that the management of the crime scene should be integrated into the scientific way of thinking rather than remain as a technical discipline as recently suggested by Harrison.     

Evaluation of the rapid analyte measurement platform (RAMP) for the detection of Bacillus anthracis at a crime scene

The aim of this study was to evaluate the accuracy and reliability of the rapid analyte measurement platform (RAMP) for presumptive identification of Bacillus anthracis spores. Test samples consisted of serial dilutions of spore preparations of several Bacillus species, including B. anthracis, which were tested, using the RAMP Anthrax test cartridge, according to the manufacturer's instructions. The fluorescence labelled antibody-antigen complexes were detected in the portable reader after 15 min following sample addition. Dilutions of common environmental and household powders were also tested to identify possible false positive results. B. anthracis spores were identified reliably in test samples containing more than 6000 spores. The test kits were highly specific, showing no cross reactivity with other Bacillus species or any environmental powders tested. The RAMP system for detection of B. anthracis spores, from environmental samples, showed consistent results under a variety of analytical conditions, enabling the trained user to provide a rapid, accurate preliminary risk assessment of a suspected bioterrorism incident.