Physical Characterization and Recovery of Corroded Fingerprint Impressions from Postblast Copper Pipe Bomb Fragments

Pipe bombs made from 1 mm thick copper pipe were detonated with a low explosive power powder. Analysis of the physical characteristics of fragments revealed that the copper had undergone work hardening with an increased Vickers Hardness of 107HV1 compared with 80HV1 for unexploded copper pipe. Mean plastic strain prior to fracture was calculated at 0.28 showing evidence of both plastic deformation and wall thinning. An examination of the external surface showed microfractures running parallel with the length of the pipe at approximately 100 μm intervals and 1–2 μm in width. Many larger fragments had folded “inside out” making the original outside surface inaccessible and difficult to fold back through work hardening. A visual examination for fingerprint corrosion revealed ridge details on several fragments that were enhanced by selective digital mapping of colors reflected from the surface of the copper. One of these fingerprints was identified partially to the original donor.     

The Recovery and Analysis of Mitochondrial DNA from Exploded Pipe Bombs*

Abstract: Improvised explosive devices (IEDs) represent one of the most common modes of arbitrarily injuring or killing human beings. Because of the heat generated by, and destruction to, an IED postconflagration, most methods for identifying who assembled the device are ineffective. In the research presented, steel pipe bombs were mock‐assembled by volunteers, and the bombs detonated under controlled conditions. The resultant shrapnel was collected and swabbed for residual cellular material. Mitochondrial DNA profiles were generated and compared blind to the pool of individuals who assembled the bombs. Assemblers were correctly identified 50% of the time, while another 19% could be placed into a group of three individuals with shared haplotypes. Only one bomb was assigned incorrectly. In some instances a contaminating profile (mixture) was also observed. Taken together, the results speak to the extreme sensitivity the methods have for identifying those who assemble IEDs, along with precautions needed when collecting and processing such evidence.     

Effect of Cutting with an Abrasive Saw on Swarf Composition

Crime scene investigators are often asked to examine swarf from break‐in sites and compare it with swarf found on a suspect. Occasionally, elemental composition of swarf from these two sources does not match. It is generally assumed that cutting metal does not induce changes in chemical composition. However, this study shows that, if a matrix contains iron, chromium, and nickel, composition of swarf produced from cutting the matrix with an abrasive saw may indeed alter. In this study, we cut a stainless steel sheet using a standard cutoff saw. Swarf was sorted and chemically analyzed by EDS/SEM, and the following relationships between chip morphology and modified composition were discovered: elongated chips remained unchanged; changes in the irregular chips appeared to be random, possibly because they are formed in a number of different ways; composition of spherical chips changed with size.     

The use of orthopedic surgical devices for forensic identification

Surgically implanted devices have become increasingly common in modern skeletal material. Therefore, having the knowledge of the variety of implanted orthopedic devices, their manufacturer, and where to find and how to use identifying numbers in such implants can assist in the identification process when traditional methods are not applicable. Orthopedic device manufacturers are required by the Safe Medical Devices Act of 1990 and the FDA Modernization Act of 1997 to track permanently implanted devices. Manufacturer information on orthopedic devices associates the orthopedic surgeon who implanted the device with the patient. By providing a current list of the most common orthopedic device manufacturers in the U.S.A. and the associated contact information, investigators will have updated tools for the individuation process. Despite numerous complicating factors regarding how device data are tracked, the information presented here can assist forensic professionals with obtaining presumptive and/or positive identifications.     

Investigative studies into the recovery of DNA from improvised explosive device containers

Apprehending those who utilize improvised explosive devices (IEDs) is a national priority owing to their use both domestically and abroad. IEDs are often concealed in bags, boxes, or backpacks to prevent their detection. Given this, the goal of the research presented was to identify IED handlers through postblast DNA recovery from IED containers. Study participants were asked to use backpacks for 11 days, after which they served as containers for pipe bombs. Eleven postdeflagration backpack regions likely to be handled were swabbed and analyzed via mini-short tandem repeats (miniSTRs) and alleles were called blind. An experimental consensus method was examined in which profiles from all regions were considered, to help identify spurious drop-in/out. Results were correct for all loci, except one that remained ambiguous. The results show that recovering DNA from IED containers is a viable approach for aiding in the identification of those who may have been involved in an IED event.     

尸体腐败微生物的研究进展

法医学死亡时间的推断已从传统的病理学诊断转变为多证据佐证的模式。自然状态下尸体腐败过程受多因素影响,其中微生物是影响尸体腐败的敏感指标,因此,尸体上微生物群落的结构的变化有可能成为死亡时间推断的新依据。本文综述了自然状态下尸体上微生物群落的演替特征及影响因素,并列举了微生物的取样、储存及检测方法,希望能为法医微生物学的研究及实践提供参考。     

Sulfuric, hydrochloric, and nitric acid-catalyzed triacetone triperoxide (TATP) reaction mixtures: an aging study

The organic peroxide explosive triacetone triperoxide (TATP) is regularly encountered by law enforcement agents in various stages of its production. This study utilizes solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) to examine sulfuric acid-, hydrochloric acid-, and nitric acid-catalyzed TATP syntheses during the initial 24 h of these reactions at low temperatures (5-9°C). Additionally, aging of the reaction mixtures was examined at both low and ambient temperatures (19-21°C) for a further 9 days. For each experiment, TATP could be readily identified in the headspace above the reaction mixture 1 h subsequent to the combination of reagents; at 24 h, TATP and diacetone diperoxide (DADP) were prominent. TATP degraded more rapidly than DADP. Additionally, chlorinated acetones chloroacetone and 1,1,-dichloroacetone were identified in the headspace above the hydrochloric acid-catalyzed TATP reaction mixture. These were not present when the catalyst was sulfuric acid or nitric acid.     

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。     

毒物代谢动力学研究在法庭科学中的应用

随着法庭科学的发展以及近年来涉及毒品、毒物等中毒案件的增加,许多研究者对毒物代谢动力学进行研究,并取得了一定的成果.本文综述毒物代谢动力学研究及其在法庭科学中的应用状况,概要介绍毒物代谢动力学的研究现状、研究方法及研究成果,以期为相关研究及实践提供参考和借鉴.     

Measuring the impact of forensic science in detecting burglary and autocrime offences

As UK investment in forensic science has increased, the government has taken a fresh interest in how far this has led to dividends in terms of the detection of crime and its reduction. The Home Office funded 'Pathfinder Project' sought to monitor and document the complex relationships between the collection and use of forensic material (looking at a range of forensic science techniques) and its impact on crime detection. The project specifically targeted the 'volume' crimes of burglary and vehicle crime. Detailed data was gathered on all stages of the process between the collection and use of forensic material and crime detection. The model falls into two conceptual phases--scene attendance to suspect identification and identification to detection. From the analysis it was found that approximately one third of burglary and autocrime scenes are visited by SOCOs. While scientific identifications are only made in a minority of burglary and autocrime offences overall, it belies their importance. About one in ten of burglary and autocrime cases are cleared up by the police and it is estimated that fingerprints and SGMPlus were a contributory factor in achieving one third of these clear ups.     

中美法庭科学实验室比较研究

本文以中美权威部门发布的统计报告以及有关文献报道的数据为基础,通过比较研究,从实验室分布、规模、人力资源、工作量、专业设置、技术标准化、资金、管理体系和信息化9个方面进行深入分析,找出双方的差异和距离,为我国法庭科学实验室的发展建设提供参考依据。     

The Identification of Chlorinated Acetones in Analyses of Aged Triacetone Triperoxide (TATP)

The organic peroxide explosive triacetone triperoxide (TATP) is regularly encountered by law enforcement agents in various stages of its production, storage, or usage. In a previous study, it has been demonstrated that isolated, rigorously purified, TATP may degrade to form a series of chlorinated acetones when directly treated with excess concentrated hydrochloric acid. The current study extends this work to examine whether this phenomenon may be measured during the more feasible scenario of aging of rudimentarily purified TATP contaminated with trace reaction mixture. It was demonstrated that solid-phase microextraction gas chromatography/mass spectrometry analyses of aged TATP that was synthesized utilizing hydrochloric acid catalyst may identify the presence of the degradation products chloroacetone and 1,1-dichloroacetone. Upon aging of TATP synthesized utilizing either sulfuric or nitric acid catalyst, no acid specific degradation products could be identified. These findings may be exploited by forensic chemists in the analyses of TATP samples.     

The Anatomy of a Pipe Bomb Explosion: Measuring the Mass and Velocity Distributions of Container Fragments

Improvised explosive devices such as pipe bombs are prevalent due to the availability of materials and ease of construction. However, little is known about how these devices actually explode, as few attempts to characterize fragmentation patterns have been attempted. In this study, seven devices composed of various pipe materials (PVC, black steel, and galvanized steel) and two energetic fillers (Pyrodex and Alliant Red Dot) were initiated and the explosions captured using high‐speed videography. The video footage was used to calculate fragment velocities, which were represented as particle velocity vector maps. In addition, the fragments were weighed. The results demonstrate a correlation between the type of energetic filler and both the size and velocity of the fragments. Larger fragments were produced by Pyrodex filler indicating a less complete fragmentation, compared with smaller fragments produced by double‐base smokeless powder. Additionally, higher fragment velocities were seen with Alliant Red Dot filler.     

Antemortem records of forensic significance among edentulous individuals

The identification of edentulous individuals is problematic due to poor provision of labelled dental prostheses. Dental records may still provide useful information for odontologists in the comparative identification process. The purpose of this study was to determine the level of forensically significant information contained within the dental records of a population of denture wearers attending the University of Manchester School of Dentistry. Two hundred and two dental records were examined and a proforma completed. The mean age of the patients was 72 years. Medical history were absent in 4% of all records and only 67.8% of the written records were rated as good. Thirty-two percent of the records contained one or more panoramic radiographs but 30% of these were over 3 years old rendering their usefulness in identification procedures questionable. In total only 18% of the examined records contained antemortem information that would enable identification. These data suggest that the process of denture marking is an essential in order to ensure that the identification of this population can be undertaken expediently by dental means.     

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     

刑事影像技术新体系

目的阐述刑事影像领域内影像技术及应用的现状和发展。方法从理论方面研究国内外刑事影像技术文献。结果提出了刑事影像影像技术新的框架体系。结论刑事影像技术三个主要组成部分是影像成像检验、影像分析检验和影像合成演示。     

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。     

法医骨组织学研究

在实际检案中 ,当现场发现的骨骼残片体积较小时 ,用解剖学观察无法进行骨骼残片的法医鉴定 ,需使用骨组织学的方法进行骨骼残片的个体识别。目前 ,这是法医人类学中一门较活跃的领域 ,即法医骨组织学。法医骨组织学的内容主要包括两个方面 :(1)骨骼残片是否属于人类骨骼 ,或属于何种动物骨骼。这方面的研究包括人类骨骼的组织学特征研究及不同动物的组织学特征研究。 (2 )人类骨骼个体识别的组织学研究。这方面的研究主要包括 ,人类骨骼的组织学特征的年龄判断 ,例如股骨、胫骨、肱骨、锁骨等 ,以及使用骨组织学方法 ,进行人类骨骼的年龄评价的准确性研究。本文对上述内容进行了综述。     

论法庭科学实验室认可的特殊要求

本文从价值观、证据资格和优质法庭科学服务3个方面分析了法庭科学实验室认可特殊性的产生根源;分析和总结了ILAC和部分国家法庭科学实验室认可的特殊要求,给此项工作在我国的开展提供了借鉴。