全国微量物证专业现状分析与发展对策研究

为全面了解我国刑事技术鉴定机构微量物证专业发展现状及存在问题，并提出对策建议，本文设计全国微量物证实验室建设情况调查问卷，应用问卷星对全国（不含港澳台）31个省、自治区、直辖市开展理化检验的307个刑事技术鉴定机构开展问卷调查，采用统计学方法对问卷结果进行分析。参与调查的307个刑事技术鉴定机构包括省（自治区、直辖市）级31个、地市级261个、区县级15个，其中通过国家实验室认可（CNAS）122个，未通过CNAS认可185个；通过资质认定304个，未通过资质认定3个；所有参与调查机构均设置理化检验实验室，绝大多数（301个，占比98.0%）未设置专门的微量物证检验部门；开展微量物证检验的机构224个，占比73.2%;307个鉴定机构共有理化检验技术人员1 463人，平均每个实验室4.77人；专业技术人员以化学及相关专业为主，占比65.0%;GC-MS和GC是最常用的理化分析仪器，分别为409台和347台，扫描电镜/能谱仪（63台）和红外光谱仪（117台）等微量物证专业常用分析设备占比相对较小；助燃剂及燃烧残留物、火炸药及爆炸残留物、油漆、射击残留物、纤维为最常见的检验对象。专业技术人...     

浅谈微量物证的提取、保存和送检要求及意义

物证是刑事技术的重要组成部分，它的存在已显示出在各类案件中的巨大应用价值，其鉴定结论作为法庭的重要证据之一。物证的种类所涉及的专业各不相同，各专业又涉及不同的鉴定项目，每个鉴定项目对物证检材及比对样品又有着各自特殊的要求。检材的提取是否规范，保存是否妥当都将直接影响到最终的鉴定结果，微量物证经过检验所提供的信息一旦被证实，便是揭露和证实犯罪的强有力的证据。在理化检验工作中，我们接触的物证种类繁多，在送检样品中经常遇到各种各样的问题，如：不规范的包装、提取方法和送检方法不当、数量和质量不符合要求等…     

基于折射率数据的玻璃物证比对检验似然比模型建立及评估

玻璃是常见微量物证，目前国内微量物证检验报告通常只列出检验数据或定性给出比对检验结论，无法量化表达物证比对鉴定结论。似然比证据价值评价方法在全世界被广泛接受，但在中国，针对玻璃物证的定量价值评价方法还未建立，给检察官和法官准确利用玻璃物证带来困难。为提升玻璃物证的证据价值，本文拟建立量化比对检验结论的似然比方法模型并进行评估。基于四大类150个玻璃样品共750个折射率的检验数据，采用高斯核密度估计方法建立似然比(LR)模型，采用直方图和两类错误率对该模型进行评估。通过建立的似然比模型计算得出同源样品间的LR值在6.58～204 500范围内，不同源的样品间的LR值在0～0.68范围内，在150个样品的自身比对中，仅有一个样品自身比对的LR<1，错误排除率为0.67%；对150个不同来源玻璃样品进行两两比对，在C²₁₅₀=11 175对比对中，有173对LR>1，错误接纳率为1.55%，两个错误率均较低，在可接受范围内。基于高斯核密度估计建立的似然比模型能够对基于玻璃折射率数据的样品比对给出满意的比对结果，可为法庭提供玻璃样品比对的...     

扫描电镜/能谱仪检验微量金属3例

当前,犯罪分子反侦察手段不断提高,许多刑事犯罪现场被人为的改变或破坏,侦查与反侦查的较量日趋激烈。微量物证检验技术在这场较量中有不可替代的重要作用。常用的扫描电镜/能谱仪是微量物证检验的重要工具,它能进行微区分析,绝对灵敏度高,检材样品前处理简单,检材用量少等优点。扫描电镜/能谱仪能最常用来检验金属、火药、射击残留物、玻璃、花粉等微量物证。本文介绍笔者应用扫描电镜/能谱仪在微量金属物证检验中的一些体会。1仪器和方法日立S-3000N扫描电子显微镜;EDAX-Phoenix能谱仪;超声波清洗器;丙酮(分析纯)。将现场样品用导电胶…     

国外微量物证检验研究进展

本文根据近年来国外法庭微量物证检验方面的研究成果,从检验对象、检验技术及发展趋势三个方面总结了当前国外微量物证的研究现状。介绍了近年来国外法庭科学家在常见的微量物证如油漆、纤维、玻璃等的检测方法和检测技术,尤其重点介绍了一些新技术如电感耦合等离子体原子发射光谱技术(ICP/AES)、微波辅助消融和等离子光谱技术(OES/ICP)、激光等离子质谱联用技术(LA/ICP/MS)等在微量物证中的应用。指出国外微量物证研究相对于国内微量物证研究在技术应用、数据库建立、数据分析、合作研究等方面的优越性。     

植物物证的法医学应用

随着植物物证在案件侦破过程中的作用日益明显,应用植物学研究方法为刑事案件提供线索、证据的“法医植物学”越来越受到关注。法医植物学常用的实验技术有形态学检验、理化检验、分子遗传学检验等。本文通过整理法医植物学研究的相关文献及案例,以列举的形式简要阐述不同检验方法的利弊,总结法医植物学应用中需要注意的问题,供案件现场勘验时参考。     

文件检验结论的证据价值及其实现

文件检验作为一种成熟的物证技术,是司法鉴定常用的手段,其检验结论对于司法鉴定有着重要的作用.本文主要从证据学角度分析文件检验结论的证据效力,归属文件检验结论的法定证据形式,同时对文件检验结果的审查情况进行探讨,深入研究证据对司法鉴定所产生的价值.     

微量生物物证提取套装在现场微量血痕DNA检验中的应用

目的探讨微量生物物证提取套装应用于提取现场微量血痕DNA的检验效果。方法将静脉血制成地面血痕。分别应用微量生物物证提取套装法和普通法提取血痕。分别于恒温摇床放置2、24、48、72、96h(每组50份)进行血痕DNA检验,对比各组检验结果。结果恒温摇床上分别放置24、48、72、96h后,微量生物物证提取套装法的DNA检出率(分别为100.00%、100.00%、100.00%、96.00%)均高于普通法(分别为62.00%、26.00%、10.00%、0),差异均具有统计学意义(P<0.05)。恒温摇床上放置2h,两种方法的DNA检出率差异无统计学意义(P>0.05)。结论微量生物物证提取套装可有效提升放置时间较久的现场微量血痕的检出率和检出时限。     

道路交通事故中微量物证的应用

微量物证的应用在频发的交通事故案件中发挥着越来越重要的作用,其广泛的存在于交通事故现场中,为处理交通事故提供了强有力的支持。本文从着重从应用角度对微量物证进行讨论。本文首先对微量物证进行了介绍,从定义、特征、种类角度做出了概述。随后结合实际案件对微量物证的应用情况分类阐释。最后结合微量物证的应用现状的不足之处,提出了几点值得注意的地方。     

带血手套腕部微量上皮细胞DNA检验1例

PCR技术应用到生物物证的检验,尤其是应用荧光复合STR基因座进行分析,使微量生物检材的检测成为可能[1]。在刑事案件中,与人体表接触过的衣服、手套等常粘附有体表脱落上皮细胞,如能对此进行检验并成功获得DNA分型数据,将为案件的侦破提供重要的线索和证据。通常情况下,因脱落上皮细胞量非常少,在检验过程中又缺乏稳定的方法,常常导致检验结果不理想。本文作者通过对一例棉线手套腕部上的脱落上皮细胞成功进行STR分型,为极微量体表脱落上皮细胞的检验提供了一种切实可行的方法。1案例2005年12月,某商店内发生入室抢劫案,两名妇女被杀害…     

试论美国纽约市法庭科学工作

纽约市是美国第一大城市,人口众多,经济发达,其法庭科学在国际上也享有声望。纽约市法庭科学部门主要分布在警察局(NYPD)和法医局(OCME)两大机构,警察系统的法庭科学机构主要负责毒品、微量物证、指纹、痕迹、枪弹及文件检验,法医局则进行DNA、毒化、法医病理、法医人类学方面的检验。本文首先介绍美国的警察制度及纽约市警察局概况,然后分别从警察局和法医局两个部门对纽约市法庭科学的部门隶属、部门设置与工作职能情况进行介绍。     

真实关联度、证据间性与意指定律——谈证据符号学的三个基本概念

真实关联度指符号反映内容的真确性程度;证据间性指不同证据符号之间相互关联、相互补足的关系;意指定律指符号的意指关系决定了结构关系.这三个术语旨在说明证据符号学的基本理论原则:证据处在一个符号关系场内,由意指关系(真实关联度)和结构关系(证据间性)构成,意指定律就是支配该符号关系场的基本规则.这个证据符号关系场与事实真相...     

国外微量物证检验研究进展

本文根据近年来国外法庭微量物证检验方面的研究成果,从检验对象、检验技术及发展趋势三个方面总结了当前国外微量物证的研究现状。介绍了近年来国外法庭科学家在常见的微量物证如油漆、纤维、玻璃等的检测方法和检测技术,尤其重点介绍了一些新技术如电感耦合等离子体原子发射光谱技术（ICP/AES）、微波辅助消融和等离子光谱技术（OES...     

案事件调查中视频证据的内容解析

案事件的调查中,常常需要专业人员出具书面的报告,对视频记载的事件过程进行描述和解释。实际案件中,视频内容的分析报告多采用时间顺序,以语言描述为主。本文提出视频内容解析的概念,综合运用图像处理、图像测量、现场实验等技术方法,对视频中人、车、物等状态及其相互关系进行定性和定量的分析。解析结果以文字与图表相结合的形式呈现,可以更清晰完整地表述视频中反映的事件过程,已在多起重特大案事件的现场视频分析中应用。对于持续时间较长、关键目标动作较复杂的案事件形成视频解析报告,有助于对事件过程的还原,提高了视频证据的证明能力。     

The Analysis of 3D Printer Dust for Forensic Applications,,

3D printers are becoming increasingly efficient and economical, and thus more widespread and easily accessible to consumers and businesses. They have been used to print nefarious objects such as guns and suppressors. Previous research has documented the release of dust particles during the printing process; however, little has been written about the morphology and chemical features that define the dust emitted by these printers. This study was undertaken to recover, analyze, and identify the dust produced during the printing process in the context of forensic trace evidence analysis. Samples were collected from a variety of 3D fused deposition modeler printers, representing both consumer and commercial grade models. This work focused on printers that use thermoplastic filaments composed of acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA), two of the most commonly used filament polymers. Swabs were used to collect dust within the printer chamber and then processed to isolate the dust particles. Particles produced from ABS filaments are most easily recognized via light microscopy through a combination of color, morphology, and fluorescence. The composition of these particles can be confirmed through analysis by either FTIR or Raman microspectroscopy. These methods can also be used to identify ABS fillers and pigments within the printer dust particles. In contrast, dust from PLA printers consistently contained finer, submicron-sized particles that could be observed by field emission scanning electron microscopy. Because the size of the particles precludes their identification using vibrational spectroscopy methods, pyrolysis-GC-MS was used to confirm the presence of PLA.     

Application of Random Match Probability Calculations to Mixed STR Profiles

Mixed DNA profiles are being encountered more frequently as laboratories analyze increasing amounts of touch evidence. If it is determined that an individual could be a possible contributor to the mixture, it is necessary to perform a statistical analysis to allow an assignment of weight to the evidence. Currently, the combined probability of inclusion (CPI) and the likelihood ratio (LR) are the most commonly used methods to perform the statistical analysis. A third method, random match probability (RMP), is available. This article compares the advantages and disadvantages of the CPI and LR methods to the RMP method. We demonstrate that although the LR method is still considered the most powerful of the binary methods, the RMP and LR methods make similar use of the observed data such as peak height, assumed number of contributors, and known contributors where the CPI calculation tends to waste information and be less informative.     

Pulmonary macrophage counts in deceased infants: baseline data for further study of infant mortality

Infant lung samples were obtained prospectively at autopsy by medical examiner pathologists in five areas of the United States and regardless of the cause of death. Four sections were examined for each case and were taken from the anterior and posterior aspects of the right and left upper lung lobes. Lung sections were stained with HAM-56 immunostain, which is specific for macrophages. Sixty-one cases were evaluated for the study. Three pathologists independently counted the number of macrophages per 40x field (10x ocular) in 10 contiguous fields near the center of each lung section examined. There was good agreement between pathologists on the average number of macrophages observed in each case. The mean macrophage count for all fields counted was 16.5 per 40x field (range 0-136), and the mean for individual cases was 16 (range 6.6-39.4). There was no observed difference between right, left, anterior, and posterior lung sections. There was a tendency for cases certified as sudden infant death syndrome to show lower macrophage counts than those with other causes of death, but the difference was of only marginal statistical significance. Seven of 10 cases in which infants died after a survival period in the hospital had a mean macrophage count greater than the overall mean of 16 per 40x field. These data suggest that mean pulmonary macrophage counts > 16 per 40x field may be a marker for causes of death other than sudden infant death syndrome or that there was a survival interval. These data may be useful as baseline data for further studies of infant mortality possibly involving pathologic changes in the lungs.     

Trajectory reconstructions. I: Trace evidence in flight

This paper reviews the use of trace evidence recovered from spent bullets in helping to establish trajectories. The use of information derived from such trace evidence combined with that from geometrical techniques of trajectory reconstruction and other data is discussed. Five cases are reviewed in which the analysis of trace evidential materials adhering to bullets was used to help reconstruct the event.     

A logical framework to ballpoint ink dating interpretation

Since its beginnings, the forensic field of questioned documents has been concerned with the dating of inks. Ink ageing processes follow complex paths. Disagreements about the feasibility of current methods have been voiced worldwide among the scientific and legal communities. This controversy has been the starting point of the present work. Its aim was that of evaluating the interpretation processes of such evidence. Subjective statistical data have been assigned from earlier works and illustrate the kind of data necessary to date ballpoint ink, and how to use it for this purpose. This work also suggests that the court and scientific requirements for standards of reliability are not yet fulfilled by actual ink dating methods for regulatory use in expert testimony.     

Estimation and evidence in forensic anthropology: age-at-death

A great deal has previously been written about the use of skeletal morphological changes in estimating ages-at-death. This article looks in particular at the pubic symphysis, as it was historically one of the first regions to be described in the literature on age estimation. Despite the lengthy history, the value of the pubic symphysis in estimating ages and in providing evidence for putative identifications remains unclear. This lack of clarity primarily stems from the fact that rather ad hoc statistical methods have been applied in previous studies. This article presents a statistical analysis of a large data set (n = 1766) of pubic symphyseal scores from multiple contexts, including anatomical collections, war dead, and victims of genocide. The emphasis is in finding statistical methods that will have the correct "coverage."Coverage" means that if a method has a stated coverage of 50%, then approximately 50% of the individuals in a particular pubic symphyseal stage should have ages that are between the stated age limits, and that approximately 25% should be below the bottom age limit and 25% above the top age limit. In a number of applications it is shown that if an appropriate prior age-at-death distribution is used, then "transition analysis" will provide accurate "coverages," while percentile methods, range methods, and means (+/-standard deviations) will not. Even in cases where there are significant differences in the mean ages-to-transition between populations, the effects on the stated age limits for particular "coverages" are minimal. As a consequence, more emphasis needs to be placed on collecting data on age changes in large samples, rather than focusing on the possibility of inter-population variation in rates of aging.