常州市武进区5年94例已破命案的回顾性研究

目的本课题收集真实案例进行回顾性研究、比对,寻找常州市武进区命案特征,总结命案现场的法医学检案重点、难点和相关实践经验。方法收集江苏省常州市武进区2006～2010年94例已破命案资料,应用Microsoft Excel软件进行一般描述性统计分析。结果 2009年、2010年案件数量略有上升,而每年的第一、三季度为命案高发季度。受害人及嫌疑人多为流动人口,男性显著多于女性,以青壮年为主。嫌疑人均学历较低,多从事打工、务农,或无业,多由纠纷升级为命案。以锐器伤及钝器伤多见,死因基本为机械性损伤和机械性窒息。结论命案发生与人口数量呈正相关。受害人及犯罪嫌疑人基本情况、作案动机、致伤工具、损伤分布、死因等均反映出了命案现场法医工作的基本内容、工作重要性及未来的研究发展方向。     

Self-inflicted stab wound for simulating self-defense?]

During a violent conflict, a young man was shot dead in front of a bar. The offender stated that he had acted in self defence after having been attacked with a knife. Taking into account the testimonies, the medical findings (f. ex. sonotomogram of the left femur) as well as the crime scene regarding the position of the body, it could not be excluded from the forensic point of view that a knife attack of the later victim had taken place. Nevertheless, the court convicted the man who had shot for murder and gave a life prison sentence.     

A preliminary investigation into the use of testate amoebae for the discrimination of forensic soil samples

We present the results of an initial investigation into the efficacy of using testate amoebae for the discrimination of soils from wet ground and puddles, as little attention has been given to these organisms in forensic science. The preservation of testate amoebae in these sediments is generally good, although test concentrations are low. Statistical analysis suggests that testate amoebae assemblages are somewhat spatially distinct and have potential to be used for soil discrimination. A case study is presented where mineralogical (X-ray diffraction) and testate amoebae analyses are used in conjunction to clarify the scene of crime in a ‘cold case’ murder enquiry. Testate amoebae were recovered from dried sediment residues on clothing 10 years after the murder. Despite these promising results, further experimental work is crucial to examine the spatial and temporal variation of amoebae assemblages in water films, wet ground and puddles before they can be added to the armoury of methods available to the forensic biologist.     

Assessing three soil removal methods for environmental DNA analysis of mock forensic geology evidence

Soil is useful in criminal investigations as it is highly variable and readily transferred. Forensic geologists use several different techniques to removal soil from evidence prior to the analysis of inorganic components. There has been recent interest from the forensic science community to analyze environmental deoxyribonucleic acid (eDNA) associated with soil to augment existing forensic analyses. Notably however, limited research has been conducted to compare commonly used soil removal methods for downstream eDNA analysis. In this study, three soil removal methods were assessed: picking/scraping, sonication, and swabbing. Three mock evidence types (t-shirts, boot soles, and trowels) were sampled in triplicate with each removal method (n = 27). Soil samples underwent DNA isolation, quantification, and amplification of four genomic barcode regions: 16S for bacteria, ITS1 for fungi, ITS2 for plants, and COI for arthropods. Amplicons were prepared into libraries for DNA sequencing on an Illumina^® MiniSeq. DNA concentrations were highest in picked/scraped samples and were statistically significant compared with swabbed and sonicated samples. Amplicon sequence variants (ASVs) were identified, and removal methods had no impact on the recovery of the total number of target ASVs. Additionally, when assessing each sample in multidimensional space, picked/scraped samples tended to cluster separately from swabbed and sonicated samples. The soil core used a reference in this study also clustered with the picked/scraped samples, indicating that these samples may be more reflective of the communities collected from soil cores. Based on these data, we identified that picking/scraping is an acceptable soil removal method for eDNA analysis.     

Evaluation of exhibits from a murder case using the lead isotope method and scanning electron microscopy

We have used a combination of lead isotopes and scanning electron microscopy to determine the relationships between different exhibits in a murder case. Samples involved lead projectiles removed from the deceased's head and a pillow, lead-rich scrapings and particles (gunshot residues) from spent cartridges and a silencer, and particles from a pillowcase. The lead projectiles had the same isotopic composition. with the lead being derived from the same dominantly geologically old source(s). The lead smear from the silencer had the same isotopic composition as the projectiles, and the lead was probably from the same source. The particles from the spent cartridges had varying elemental compositions ranging from PbO to PbCuZn +/- Ba with or without Si and are consistent with derivation from the primer. The lead isotopic compositions of the particles from the spent cartridges show some variations, but these are markedly different from those of the projectiles, indicating lead from a mixture of geologically old and geologically young lead. The particles from the pillowcase were extremely small (usually <50 microm size) and showed varying isotopic compositions, some consistent with the gunshot residue from the cartridges. As the exhibits had been handled extensively prior to the present investigation, including some being sent to North America, there is a high likelihood that handling was not done in clean room environments and may have been contaminated. In this instance, as we were concerned about contamination, especially of the pillowcase, we felt contamination negated use of the results for assistance in proving the innocence or guilt of the accused. A combination of high-precision lead isotope measurements with scanning electron microscopy provides a powerful tool for forensic investigations if precautions are taken in handling the exhibits.     

Diagnostic values of polysomnography in forensic medicine

A man accused of a first-degree murder of a two-year-old girl claimed that he had not been conscious during the time of the alleged murder. The possibility that he may have committed the crime while "sleepwalking" was raised. The forensic psychiatrist looked to the sleep disorders facility to conduct polysomnographic investigation of the accused in order to investigate the possibility that he had a parasomnia. Overnight sleep recordings with video surveillance carried out for two consecutive nights showed no evidence of parasomnia. On the basis of the full assessment, the final report of the forensic psychiatrist did not support a legal defense of non-insane automatism and "sleepwalking" was withdrawn as a possible defense by the lawyer of the accused.     

Cascading Bias of Initial Exposure to Information at the Crime Scene to the Subsequent Evaluation of Skeletal Remains,

Thirty‐eight participants took part in a study that investigated the potential cascading effects of initial exposure to extraneous context upon subsequent decision‐making. Participants investigated a mock crime scene, which included the excavation of clandestine burials that had a male skeletal cast dressed either in female or gender neutral clothing. This was followed by a forensic anthropological assessment of the skeletal remains, with a control group assessing the same male skeletal cast without any clothing context. The results indicated that the sex assessment was highly dependent upon the context in which participants were exposed to prior to the analysis. This was especially noticeable in the female clothing context where only one participant determined the male skeletal cast to be male. The results demonstrate the importance of understanding the role of context in forensic anthropology at an early stage of an investigation and its potential cascading effect on subsequent assessments.     

The Testimony of Forensic Identification Science: What Expert Witnesses Say and What Factfinders Hear

This research examined how variations in the presentation of forensic science information affect factfinders’ judgments in a trial. Participants read a summary of a murder case, the critical testimony being the results of a microscopic hair comparison given by a forensic expert. Across two experiments we manipulated how the expert expressed his results, whether he gave an explicit conclusion concerning identity of the hair, and whether the limitations of forensic science were expressed during trial. Qualitative testimony was more damaging to the defense than quantitative testimony, conclusion testimony increased the defendant’s culpability ratings when findings were presented quantitatively, and expressing limitations of forensic science had no appreciable effect. Results are discussed in terms of factfinders’ interpretation of forensic identification evidence.     

代谢物组学及法医学新机遇——创建代谢物组学数据库及专家系统的设想

法医学DNA技术促成了法医学实践的一次飞跃,其建立的数据库策略为后续的研究提供了可贵的借鉴;2004年召开的人类基因组大会提出并肯定了代谢物组学的理论和技术,该技术相对于目前应用的其它技术并结合法医学的实践需要,具有更广阔的应用前景,本文借鉴DNA技术成功的经验,首次提议建立代谢物组学数据库及基于该数据库的专家系统,为解决目前法医学难以解决的难题,促成法医学继DNA技术之后新飞跃进行探索.     

A comparison of the length and width of static inked two-dimensional bare footprints found on a hard compared to a soft surface

In forensic intelligence-gathering it would be useful to evaluate if there are differences between static inked bare footprints captured on hard surfaces compared to soft surfaces. This was undertaken using samples from 30 undergraduate students. Initially a static footprint was taken for each participant on a hard surface and this was followed by a static footprint on a soft surface. On both occasions, the participants stood on an inkless mat and then on reactive paper, creating a two-dimensional print. The Reel method was used to analyse each footprint and the print was measured to see whether a difference existed between length and width (forefoot and rearfoot width) on a hard surface compared to a soft surface. The conclusion from this study was there is a statistically significant increase in length and width of a static bare footprint on a soft surface as opposed to a hard surface. If a forensic footprint examiner compares static bare footprints found on a soft surface and compares them to a static bare footprint of the same foot taken later, then the increase in both length and width of the footprints on a soft surface should be considered in the evaluation.     

Unusual results due to transfused blood.

During a murder enquiry, the forensic science investigation used PGM and EAP blood grouping systems and detected a mixture of blood on the deceased's jacket. The blood groups matched those of the deceased and accused. The results of DNA analysis, however, proved that only a single source of DNA, matching the deceased, was present. Supplementary information relating to the transfusion of the individual whilst still wearing his clothing led the authors to conclude that a mixture of transfused blood and the individual's own blood had effused from his body via a stab wound, and onto his clothing.     

Can analysis of a small clod of soil help to solve a murder case?

Soil forensics utilizes extensive soil information to answer legal questions and test hypotheses. The main difficulty often is the determination of different variables from a small amount of soil sample collected on the suspect. We developed a sequential mineralogical and chemical analyses to assess a limited quantity of soil vestiges (0.5 g) from a suspect's vehicle (adhered to the outside rear-view mirror and to the left front fender) involved in a murder case and compared them with the surface samples found at the victim's body disposal site at the Graciosa Road, Paraná State, Brazil. All results affirm that the suspect’s vehicle could have been in contact with the edge of the Graciosa Road, approximately the place where the victim’s body was located. As a result of the soil analysis and comparison, the results support the likely contact of the suspect’s vehicle with the crime scene.     

Microbial metagenome profiling using amplicon length heterogeneity-polymerase chain reaction proves more effective than elemental analysis in discriminating soil specimens

The combination of soil's ubiquity and its intrinsic abiotic and biotic information can contribute greatly to the forensic field. Although there are physical and chemical characterization methods of soil comparison for forensic purposes, these require a level of expertise not always encountered in crime laboratories. We hypothesized that soil microbial community profiling could be used to discriminate between soil types by providing biological fingerprints that confer uniqueness. Three of the six Miami-Dade soil types were randomly selected and sampled. We compared the microbial metagenome profiles generated using amplicon length heterogeneity-polymerase chain reaction analysis of the 16S rRNA genes with inductively coupled plasma optical emission spectroscopy analysis of 13 elements (Al, B, Ca, Cu, Fe, K, Mg, Mn, Na, P, S, Si, and Zn) that are commonly encountered in soils. Bray-Curtis similarity index and analysis of similarity were performed on all data to establish differences within sites, among sites, and across two seasons. These data matrices were used to group samples that shared similar community patterns using nonmetric multidimensional scaling analysis. We concluded that while chemical characterization could provide some differentiation between soils, microbial metagenome profiling was better able to discriminate between the soil types and had a high degree of reproducibility, therefore proving to be a potential tool for forensic soil comparisons.     

The Forensic Confirmation Bias: A Comparison Between Experts and Novices

A large body of research has described the influence of context information on forensic decision‐making. In this study, we examined the effect of context information on the search for and selection of traces by students (N = 36) and crime scene investigators (N = 58). Participants investigated an ambiguous mock crime scene and received prior information indicating suicide, a violent death or no information. Participants described their impression of the scene and wrote down which traces they wanted to secure. Results showed that context information impacted first impression of the scene and crime scene behavior, namely number of traces secured. Participants in the murder condition secured most traces. Furthermore, the students secured more crime‐related traces. Students were more confident in their first impression. This study does not indicate that experts outperform novices. We therefore argue for proper training on cognitive processes as an integral part of all forensic education.     

Environmental hazards of interest to the forensic pathologist

The hazards associated with occupational exposure to various workplace contaminants (lead, silica, etc.) have been known for a number of years. Until recently, the potential toxic effects of exposures on the male reproductive system had not been appreciated. This article not only discusses recent studies in that area, but gives clinical examples of how environmental exposures (water, soil, air, and dwellings) can affect various organs in the human body. Awareness that these injuries can occur without obvious relationship to these environmental exposures may help the forensic pathologist discover previously unsuspected hazards.     

Forensic Analysis of a Contact Lens in a Murder Case

Contact lenses have had rare relevance in trials and/or investigations. After 5 years of burial, orbital remnants were retrieved from an exhumed body and subsequently identified as a key piece of material evidence in a murder trial. The exhumed case materials were evaluated under laboratory conditions and were determined to be contact lens remnants. Contact lens fracture and burial simulation studies were performed to provide additional corroboration of the physical findings of the exhumed contact lens remnants. This material evidence was instrumental in providing factual proof refuting the defendant's testimony in the murder trial. A brief history of contact lens composition and use is provided for understanding the methods and observational results. This forensic case study represents the first published documentation of a contact lens from an exhumed body being used in a murder investigation and establishes an operational procedure for future forensic contact lens examinations.     

Mephitic projects: a forensic leisure science analysis of the BTK serial murders

Although it has been suggested among both forensic experts and a small number of leisure scientists that serial murder may be a form of recreational leisure, such suggestions remain largely unexplored both theoretically and empirically. Given the absence of scholarship on this possibility, this project explored and analyzed the structure and function of leisure activities within an unusual case (Dennis Rader) of serial murder. A thorough analysis of relevant case documents confirmed that serial murder itself can be experienced by the killer as a form of recreational leisure with the potential for optimal psychological experience (flow), and that various leisure activities may function in specific ways within the serial murder process. An unexpected finding in this case was that leisure, specifically project-based leisure, served to structure specific killings. Findings provide valuable new insights for forensics behavioral experts that may be used to guide future research.     

Hair as a source of forensic evidence in murder investigations

Obtaining palynological and other botanical evidence from murder victims is becoming part of routine mortuary protocol in the United Kingdom. Forensic pathologists are often keen to cooperate in the collection of classes of material that have, in the past, been considered to be of little importance in criminal investigation. Work over the last eight years has demonstrated the great value in scrutinising cadavers for the presence of plant material and/or soil stains. Macroscopic plant remains and palynomorphs (pollen, spores and other microscopic entities) retrieved from skin and hair have allowed the differentiation of murder scenes from places of eventual deposition. Furthermore, although the opportunity has not yet presented itself, obtaining palynological evidence from the hair of suspects is feasible. During an offence, the offender might have had physical contact with foliage or the ground. Pollen and spore assemblages picked up by hair during that activity might provide forensic evidence for contact. Brief details of some aspects of case histories are presented to demonstrate the value of sampling cadavers. One case has been through the courts while the other is ongoing and, therefore, cannot be identified.     

Serial killers with military experience: applying learning theory to serial murder

Scholars have endeavored to study the motivation and causality behind serial murder by researching biological, psychological, and sociological variables. Some of these studies have provided support for the relationship between these variables and serial murder. However, the study of serial murder continues to be an exploratory rather than explanatory research topic. This article examines the possible link between serial killers and military service. Citing previous research using social learning theory for the study of murder, this article explores how potential serial killers learn to reinforce violence, aggression, and murder in military boot camps. As with other variables considered in serial killer research, military experience alone cannot account for all cases of serial murder. Future research should continue to examine this possible link.