Enhancement of rapid lifetime determination for time-resolved fluorescence imaging in forensic examination

An enhancement method of rapid lifetime determination is proposed for time-resolved fluorescence imaging to discriminate substances with approximate fluorescence lifetime in forensic examination. In the method, an image-exclusive-OR treatment with filter threshold adaptively chosen is presented to extract the region of interest from dual-gated fluorescence intensity images, and then the fluorescence lifetime image is reconstructed based on the rapid lifetime determination algorithm. Furthermore, a maximum and minimum threshold filtering is developed to automatically realize visualization enhancement of the lifetime image. In proof experiments, compared with traditional fluorescence intensity imaging and rapid lifetime determination method, the proposed method automatically distinguishes altered and obliterated documents written by two brands of highlighters with the same color and close fluorescence lifetime.

From De Facto Fact-finder to Expert Witness? Transition of Forensic Examination in China

Forensic examination plays an important role in China's judicial system,especially in the fact-finding process of both civil and criminal proceedings.Since 2005,this system has experienced gradual,yet significant changes.This paper seeks to examine the major themes of these changes in the context of the continued conceptual reformulation and structural realignment of civil and criminal procedures and the ongoing effort to codify evidence law with transforming impact on China's judicial system and culture.Emphasis is given to the transition of the forensic examination system from an officially(both administrative and judicial)administered fact-finding mechanism with powerful impact on the courts'truth-seeking activities to,at least partially,an expert witness system with significant participation and control by the parties5 to judicial proceedings.A convergence of influence from both the continental inquisitorial tradition and the common law adversarial structure appears to have strongly informed the process and direction of the Chinese forensic examination reform.This paper attempts to explain the reasons for this convergence of influence,identify the trend and direction of this development,and provide observations and suggestions for further improvement of the forensic examination system in several key aspects with particular reference to the legal principles and judicial practices under the Federal Rules of Evidence of the United States.

The Role of Forensic Examination at Trials in China

Expertise gains increasing acceptance and importance at trials in China.Currently,the forensic examination quality management system of China has been preliminarily established.There are problems,however,for example,laws and regulations related with forensic examination are not comprehensive,forensic institutes pursue their own economic profits excessively and judges sometime have undue blind faith in scientific evidence in fact-finding.These are hindering forensic examination from being put into full play duly.In 2005,the Decision of the Standing Committee of the National People's Congress on the Administration ofForensic Examination strengthened the neutrality of forensic institutes.The Criminal Procedure Law and the Civil Procedure Law revised in 2012 initially set up the expert assistant system,which is expected to break the excessively credulous but unjustified belief in scientific evidence and solve pertinent problems.We need to focus on the following aspects:First and foremost developing a unified set of rules on forensic examination;secondly,judges need to strengthen their own ability to review scientific evidence and determine its reliability;thirdly,we should actively promote fundamental legal education refonn to remedy the insufficiency of legal understanding of forensic science;and finally,the existing expert assistant system must be further improved to help judges and litigants efiectively to identify and use expertise.

Practical Straits of the Forensic Examination in China

With the revision of the Criminal Procedural Law of the PRC and the Civil Procedural Law of the PRC in 2012,it has entered a new historical stage of litigation system and made significant progress in forensic examination system in China.However,for a long time,the illegal forensic examinations have been commonly seen in forensic practice,the right to start the forensic examination process only lies with public security and judicial authorities,while the parties only have the limited right to apply for supplementary forensic examination or re‑examination.To the problem of experts’refusal to appear in court to testify,the Criminal Procedural Law and the Civil Procedural Law have further improved the expert testimony system,but the situation has not fundamentally changed.To compensate for judges’lack of knowledge of professional issues,the expert advisor system is introduced,but there are no workable rules.Besides,judges depend too much on and accept the expert opinions blindly become a common phenomenon in the proceedings.

Confrontation and Integration: The Present and Future of Forensic Examinations on Medical Damage in China

In China,two administrative regulations and judicial interpretations related to forensic examinations of medical damage were issued from March 2017 to June 2018.In chronological order,they were interpretation of the supreme people’s court on several questions concerning the application of law in the trial of disputes over liability for medical damage and regulations on the prevention and handling of medical disputes.Those two laws,especially the regulation,have had a fundamental impact on the pattern of forensic examinations on medical damage.This paper systematically reviews the current status and existing problems with forensic examinations on medical damage following implementation of the law of tort liability;it discusses new concepts of procedures,institutional arrangements,and the selection of examiners for forensic examinations on medical damage.We believe that through the regulation,the dualistic confrontation status of forensic examinations on medical damage will gradually change toward integration.We consider that forensic examinations of medical damage will face three challenges in the future:(1)enhancing the establishment of standards;(2)undertaking theoretical research into forensic examinations onmedical damage;and(3)promoting the development ofinterdisciplinary identification specialistsmajoring in both medicine and law.Only in this way will it be possible to rectify the current dilemma with forensic examinations on medical damage in China.

利用解吸电喷雾电离-质谱成像技术(DESI-MSI)检验添改文件1例

书写笔字迹成分的差异对于检验可疑文件是否存在添改至关重要。本文针对一起添改文件检验,利用解吸电喷雾电离-质谱成像技术(DESI-MSI)检验可疑字迹,通过成像直观地反映出检材笔迹添改情况,确定可疑字迹的添改部位,并利用化学计量学对字迹成分数据进行了聚类分析。与传统光学检测法、光谱法相比,该方法可检测到书写笔字迹更多的物质信息,为此类案件的鉴定提供了新的思路。

《文件上可见指印鉴定技术规范》解析

司法鉴定行业技术标准体系在不断完善,各学科专业领域的技术标准也在更新和充实。SF/T 0142-2023《文件上可见指印鉴定技术规范》是在SF/Z JD0202001-2015《文件上可见指印鉴定技术规范》的基础上,结合鉴定实际情况进行充实和完善所形成的指印鉴定技术体系新成果。本文立足于文件上可见指印鉴定实践,通过对比2023版和2015版《规范》,从基本结构调整、主体内容变化、对2023版《规范》的总体评价以及适用要点4个方面进行分析,为学习贯彻《文件上可见指印鉴定技术规范》提供基本思路。

拉曼光谱在文件检验中的应用及进展

拉曼光谱作为一种分子“指纹”光谱,以其简便、快捷、无损的分析特点在文件检验中发挥着重要作用,且随着科技的发展,一些新型拉曼光谱技术及人工智能工具使其得到更加广泛的应用。通过介绍拉曼光谱的原理及分类,重点综述拉曼光谱在文件检验领域的国内外应用现状及研究进展,包括文件制作工具墨迹鉴别、文件制作时间检验、变造文件检验及特种文件检验,提出拓展拉曼光谱与其他检验技术或分析方法结合、拓宽检验范围、逐步完善拉曼光谱数据库建设等应用前景,以推动文件检验朝着更加规范、科学、高效的方向发展。

签名笔压特征的计算机辅助性量化分析研究

目的在签名鉴定中能够快速准确地发现并分析笔压特征,实现对纸笔签名和电子签名的关联检验。方法开发了静态签名笔压特征分析系统,对纸笔签名的笔压进行可视化分析;开发了动态签名笔压特征分析系统,对电子签名的笔压进行量化分析。结果利用两种系统,鉴定人能够准确对黑色中性笔签名进行笔压可视化检验、对电子签名进行笔压量化检验以及对两类签名进行笔压特征关联检验,提升签名鉴定的正确率。结论静态签名和动态签名笔压分析系统能够辅助实现签名笔压特征的分析与量化检验。

国际标准ISO/IEC24790解读及在印刷文件检验中应用展望

采用平板扫描仪、数码相机等图像捕捉设备,将印刷文件转化为数字图像加以检验目前是文书鉴定领域研究的热点,这种方法与页面经扫描后成为图像的数字印刷有相似之处,对数字印刷图像质量的评估方法或可适用于分析文件。本综述从标准内容、度量方式、与国内标准比较及在印刷文件检验中的应用性四个方面,对含有较为完备的印刷质量评估方法的国际印刷质量评估标准ISO/IEC 24790进行详细解读,重点介绍了ISO/IEC 24790中大面积图形图像质量属性、字符和线条图像质量属性评估方法,并对引入基于ISO/IEC 24790标准的新方法在鉴定领域未来发展方向作出了展望。

傅里叶变换红外光谱技术在法庭科学中的应用现状

傅里叶变换红外光谱技术因其方法简单快捷、结果准确直观、样品损耗小、检测成本低廉而被认为是适合分析各类物证的技术之一。通过介绍傅里叶变换红外光谱技术的原理及运用傅里叶变换红外光谱技术进行死后间隔时间推断、避孕套有关成分分析、微生物鉴定、土壤分析和车辆物证分析等几个方面阐述了其在法庭科学领域中的研究和应用现状,希望能够为该技术在法庭科学中的应用提供参考,并为鉴定相关案件中的物证提供一种新的思路。

笔迹鉴定标准比较研究

近年来,随着我国法庭科学的迅猛发展,国家更新了一批鉴定标准和技术规范,但由于我国司法体制的独特性,相关标准在适用时依然会造成困惑。立足标准的适用性并运用比较法的思维方式,通过对欧洲和美国笔迹鉴定相关标准分别进行介绍,并进一步与我国笔迹鉴定标准进行比较研究,发现不同标准制定组织所制定的鉴定标准在基本架构、标准内容、结论表述方式等方面均有不同。针对上述比较发现的不同,以小窥大,分析差异的产生原因,同时注意到国内笔迹鉴定标准在内容和体系上亦有不同,对此进行分析并结合我国笔迹鉴定现状提出建议,以期为笔迹鉴定实践及未来标准修订带来启示。

高素质法医学本科生法医病理心脏检验专项能力研究

本研究主要通过改变实验教学模式,将心脏解剖学、组织学与病理学等学科进行知识点融合并进行系统化培训,克服传统教学中将上述各学科分开学习的缺点,经过系统化培训可使学生在短期内掌握心脏理论知识体系,并明显提高实践技能,有利于掌握心脏有关疾病死亡案件的死因分析,进而提高法医病理检案能力。因此,本项目将法医病理学案例纳入法医学本科生的前期教育中,将真实的和具有代表性的法医病理学案例融入法医病理学实验课程,引导学生积极参与将理论应用于实践的能力训练“心脏检验”,提高学生学习积极性,并通过“器官系统+组织病理学为中心”教学模式的培训,即提高学生法医病理学实践技能,又加强对专业理论知识的系统培训,为基层公安机关法医培养提供专业和技术保障。

The classification of handwriting features of the Kazakh language written in Latin script

In 2017,the Republic of Kazakhstan began the phased transition of its alphabet from Cyrillic to Latin script.This transition has presented significant challenges to Kazakhstani document examiners,who have yet to develop appropriate methodologies for the analysis of handwriting samples written in the Kazakh language using Latin letters.This study aims to identify distinguishing macro and micro features of letters within Kazakh writing samples produced using the Latin alphabet and determine their frequencies of occurrence and discriminating power indices.Micro features were examined using the four most frequently appearing letters:“a”,“y”,“e”and“n”.A comparative analysis of tested Latin letters with those of a similar configuration in Cyrillic demonstrated differences in the number of distinguishing features,as well as in the frequency of occurrence and discriminating power indices of similar features.These results show that separate statistical bases should be used for Latin and Cyrillic letters when analysing handwriting samples based on the frequencies of occurrence of micro and macro writing features.

纤维物证热损伤检验研究进展

在火灾、爆炸等事故调查中,对纤维热损伤痕迹特征进行分析,可为锁定嫌疑人、查明事实、重建现场及原因认定起到重要的作用。本文对国内外对人体毛发和纺织纤维的热损伤相关研究进行梳理,并对未来的研究方向进行了展望,以期为相关研究及事故调查应用提供参考。

金属物证检验及其在法庭科学领域中的应用

金属物证在法庭科学领域的应用由来已久,其检验通常归于微量物证的检验范畴。金属物证通常以金属颗粒、附着物或熔融态出现在杀人、盗窃、枪击、电气火灾等多种类型的案事件中,检验方法通常包括扫描电镜–能谱法、金相检验法、X射线荧光光谱法、电感耦合等离子体质谱法等多种方法。通过金属物证的检验,可以起到确定案事件性质、提供侦查线索以及完善证据链的作用。本文通过对近年来国内法庭科学领域金属物证检验文献进行提取,以知识图谱分析工具VOSviewer进行分析,就金属物证的多种检验方法进行综述,了解其在法庭科学领域的应用现状,旨在为涉案金属物证的提取和检验提供借鉴作用。

司法鉴定实践中基于Android即时通讯记录的真实性实例分析探究

目的即时通讯应用程序(如微信、QQ和钉钉)提供便捷服务的同时,也因其特性而使其成为网络犯罪分子进行恶意活动的潜在目标。因此,即时通讯记录成为网络调查案件的重要证据来源。然而,目前针对即时通讯记录真实性的研究相对匮乏,这可能会使其在司法实践中失去公信力。方法结合司法鉴定工作实务,对即时通讯记录的存储结构进行分析,如文本信息、图片、视频等多种数据类型在设备中的存储路径和格式,揭示其内在的数据组织和存储机制。同时,结合数据特征,如时间戳、发送/接收的信息内容以及逻辑合理性等方面,进一步对即时通讯记录的真实性进行探究。结果从基于Android即时通讯记录真实性司法鉴定实例研究出发,所探讨的方法能够有效鉴别即时通讯记录存在窜改痕迹。结论相关鉴定技术的研究对通讯记录的真实性鉴定具有重要的理论研究意义和实践应用价值,有助于为从事数字取证的研究人员提供重要参考。

一起强奸致孕案中葡萄胎的亲子鉴定分析

葡萄胎是异常受精所致的妊娠滋养细胞疾病。涉及葡萄胎组织的亲子鉴定在法医实践中相对罕见。在一起强奸致孕案中,受害人怀孕时未满14周岁,经医院诊断为葡萄胎。流产组织的形态和基因分型特征符合完全性葡萄胎的特点,但被控嫌疑人和流产的葡萄胎组织不符合亲子关系。笔者结合相关文献对检验结果进行分析,通过DNA数据库单亲比对为追溯犯罪嫌疑人提供线索,并对本案相关人员样本和流产葡萄胎组织进行了多次复检,增加了X-STR和Y-STR基因座检验,进一步明确了流产葡萄胎组织的生物学父亲。本文对该案件的检验鉴定过程进行分析和探讨,以期为同类型案件的办理提供启示。

Research on Subjective Bias Cognition Effect in Handwriting Identification

This article starts from the point of view that handwriting examination is dependent on empiricism and by analyzing the core steps ofhandwriting identification explains that it might be influenced by subjective bias.In practice,examiners cannot avoid biases in decision-making;instead,we must accept the existence of subjective bias in handwriting identification and then discuss its impact;for instance,feature selection in the process of comprehensive evaluation,which involves a comparison of the number and quality of similarities and differences between a questioned sample and the references.While we conclude that comprehensive evaluation is the most important step in the identification process,industries in China do not stipulate explicit and transparent criteria for it,making it hard to numerically quantify the characteristics ofhandwriting identification.In this article,forensic examiners5 opinions on handwriting identification were obtained through a survey.One finding was that most handwriting examiners believe that handwriting identification is subject to subjective bias.In addition,they believe that the subjective cognition of handwriting identification can somehow help actively produce the correct opinion;before the examination,most handwriting examiners think that they should understand the context and so on.Finally,through the questionnaire,which contained variations such as the same case with different background information,different cases with the same background information,and the same case with or without context,it was concluded that handwriting identification does have certain subjectivity.However,which kind of factors influence this subjectivity is not presently clear.Furthermore,it is difficult to control uncertainties when fbnnmg an opinion on identification.An alternative way is to perform scrutiny after the formulation ofhandwritmg opinions;for example,internal and external reviews such as appearing in court.

财务会计事实刑事查证方法及其优化

通过财务会计资料指证、印证、论证犯罪嫌疑和事实,可以达到发现线索、核实供述、固定证据、支持诉讼等目的。实践中,侦查机关需要专业程度高、司法成本低、程序合法、形式规范的查证方法来满足办案需求。目前,资金分析、审计和司法会计鉴定等常用方法存在着不少问题,迫切需要探索现行财务会计事实查证方法的改进措施。加强侦查机关自身力量建设和优化社会面专业工作是一条理想的改进路径,但实施落地均有一定困难;而通过司法会计检查方法来替代审计,可以实现内外结合、取长补短、高效简便的目标,具有明显的推广价值。