Using Alkylate Components for Classifying Gasoline in Fire Debris Samples

The characteristic that discriminates gasoline from other ignitable liquids is that it contains high‐octane blending components. This study elaborates on the idea that the presence of gasoline in fire debris samples should be based on the detection of known high‐octane blending components. The potential of the high‐octane blending component alkylate as a characteristic feature for gasoline detection and identification in fire debris samples is explored. We have devised characteristic features for the detection of alkylate and verified the presence of alkylate in a large collection of gasoline samples from petrol stations in the Netherlands. Alkylate was detected in the vast majority of the samples. It is demonstrated that alkylate can be detected in fire debris samples that contain traces of gasoline by means of routine GC‐MS methods. Detection of alkylate, alongside other gasoline blend components, results in a more solid foundation for gasoline detection and identification in fire debris samples.     

X‐ray Diffraction and Rietveld Refinement in Deferrified Clays for Forensic Science

Soil vestiges might provide information about a crime scene. The Rietveld method with X‐ray diffraction data (RM‐XRD) is a nondestructive technique that makes it possible to characterize minerals present in the soils. Soil clays from the metropolitan region of Curitiba (Brazil) were submitted to DCB treatment and analyzed using XRD with CuK_α radiation in the step‐scan mode (0.02° 2θ/5 s). The GSAS+EXPGUI software was used for RM refinement. The RM‐XRD results, together with the principal component analysis (PCA) (52.6% total variance), showed the kaolinite predominance in most analyzed samples and the highest quartz contents in “site 1.” Higher anatase, and gibbsite and muscovite contents influenced discrimination, mainly in “site 3” and “site 1,” respectively. These results were enough to discriminate clays of four sites and two horizons using a reduced amount of sample showing that the technique can be applied to the investigation into soil vestiges.     

Discrimination of Geographical Origin of Asian Garlic Using Isotopic and Chemical Datasets under Stepwise Principal Component Analysis

Isotopic compositions of δ²H, δ¹⁸O, δ¹³C, and δ¹⁵N and concentrations of 22 trace elements from garlic samples were analyzed and processed with stepwise principal component analysis (PCA) to discriminate garlic's country of origin among Asian regions including South Korea, Vietnam, Taiwan, and China. Results indicate that there is no single trace‐element concentration or isotopic composition that can accomplish the study's purpose and the stepwise PCA approach proposed does allow for discrimination between countries on a regional basis. Sequentially, Step‐1 PCA distinguishes garlic's country of origin among Taiwanese, South Korean, and Vietnamese samples; Step‐2 PCA discriminates Chinese garlic from South Korean garlic; and Step‐3 and Step‐4 PCA, Chinese garlic from Vietnamese garlic. In model tests, countries of origin of all audit samples were correctly discriminated by stepwise PCA. Consequently, this study demonstrates that stepwise PCA as applied is a simple and effective approach to discriminating country of origin among Asian garlics.     

Myocardial Bridging: A Meta‐Analysis of Prevalence

The main objective of this article was to analyze prevalence data about myocardial bridging (MB) in published studies. To this purpose, we performed a meta‐analysis of studies published in English literature that contained data about the prevalence of MB and its anatomical characteristics. The overall prevalence was 19% (CI: 17–21%); autopsy studies revealed an overall prevalence of 42% (CI: 30–55%), CT studies 22% (CI: 18–25%), and coronary angiography 6% (CI: 5–8%). Most bridges were located on the left anterior descending artery (82% overall, 63% on autopsy studies), had a mean thickness of 2.47 mm and a mean length of 19.3 mm. In conclusion, autopsy studies should be the gold standard in evaluating the actual prevalence of myocardial bridges, while in vivo high‐resolution CT scanning should be preferred to coronary angiography studies.     

Classification Improvements in Automated Gunshot Residue (GSR) Scans

Classification of particles as gunshot residues (GSRs) is conducted using a semiautomatic approach in which the system first classifies particles based on an automatic elemental analysis, and then, examiners manually analyze particles having compositions which are characteristic of or consistent with GSRs. Analyzing all the particles in the second stage is time consuming with many particles classified by the initial automated system as being potentially GSRs excluded as such by the forensic examiner. In this paper, a new algorithm is developed to improve the initial classification step. The algorithm is based on a binary tree that was trained on almost 16,000 particles from 43 stubs used to sample hands of suspects. The classification algorithm was tested on 5,900 particles from 23 independent stubs and performed very well in terms of false positive and false negative rates. A routine use of the new algorithm can reduce significantly the analysis time of GSRs.     

Cranial Backspatter Pattern Production Utilizing Human Cadavers

A backspatter pattern results from blood drops that travel retrograde to an applied external force. Historically, an array of animals and nonhuman objects have been used to create and study backspatter patterns. In this study, backspatter patterns captured on foam core targets that were placed 45.72 cm (18 in) behind the impact site (occipital area of the skull) were produced by cranial gunshots to human cadavers that were reinfused with fresh defibrinated bovine blood. These patterns were compared to the backspatter patterns produced by shooting blood‐soaked sponges, a typical simulant used in controlled studies of backspatter pattern production and characteristics. The backspatter pattern produced by shooting an actual human head was found to be different than those of blood‐soaked sponges in the number of stains produced, the size and size range of the stains, and the stain dispersion patterns.     

QuEChERS方法在法医毒物分析领域的研究进展

在中毒或疑似中毒案件中,毒物鉴定对于提供侦查线索与犯罪证据、澄清案件性质、还原犯罪过程具有重要意义。基于液液萃取和分散固相萃取原理而建立起来的QuEChERS方法,由于其快速、简单、廉价、高效、可靠、安全等优势,正逐渐应用于法医毒物分析的样品前处理过程中。本文综述了QuEChERS方法的基本原理及其在提取和净化等过程中的优化改进,重点详述近年来QuEChERS方法在法医毒物分析领域的应用现状,并对未来发展方向进行展望。     

法官对专家辅助人意见的采信与心证形成的路径分析

2012年《民事诉讼法》规定了专家辅助人两种出庭情形:与鉴定人进行质证;对案件所涉专业问题发表意见。两种情形不仅在事实认定中承担着本证与反证的不同功能,其意见效力、法官采信的逻辑亦有差别。目前,专家辅助人意见在我国不属于法定证据,2015年《民事诉讼法司法解释》将其视为当事人陈述的规定,更加弱化其效力,导致实践中法官在采信专家意见时难以操作。因此,赋予专家辅助人合法的诉讼地位和法定证据效力,并对专家辅助人出庭的条件、资质要求、意见属性、法院审查标准等方面予以规定,不仅完善立法,也具有非常重要的实践意义。     

影响性刑事冤假错案的产生、纠错、追责与民意的关联考察——以22起影响性刑事冤假错案为主要研究范本

民意的影响是冤假错案产生的诱因之一。不理性的民意极易虚构出貌似合理的"案件事实"并以此给司法机关施压。基于民意的压力,司法机关往往更多注重有罪证据,忽视无罪证据。命案必破、限期破案、疑罪从轻等刑事政策、司法理念,都是对民意诉求的顺应,也是促成冤假错案的诱因。民意对影响性冤假错案的纠错有积极意义,但仍应回归法治轨道。样本案件中,民意推进了冤假错案纠错程序的启动、纠错的及时,但没有制度化。民众对司法活动的认知不够理性,对错案追责的民意表达亦非建立在理性认知的基础之上。我国有必要培育理性的民意,形成民意与刑事司法的良性互动。     

党领导立法的规范分析与完善路径

在规范分析层面,党领导立法的语境是在党的机构和全国人大及其常委会产生之后的事情。我国现行《宪法》的制定开启了党领导立法的话语和实践探索。经由对党的规范性文件的分析,党领导立法的特点和规律得以突显。这些特点包括重申党领导立法必须坚持的原则不变;党领导立法的结构体系和格局更加具体;党领导立法的工作思路的变化为完善党的领导勾勒了基本路径。党要引领民主立法、科学立法和依法立法的方向;同时支持人大在立法中发挥主导作用。