浅析人造指模印和现实手印之间的差异

随着人造指模的出现以及在网络上的热销，为制作指模而轻易地将私人的指纹信息外泄，会引起民事甚至是刑事上的麻烦，笔者通过制作成的硅胶指模捺制指模印，与手指捺制的手印进行比较，从而查找其差异。     

香港的刑事技术工作

香港刑事技术检验机构概况内地统称为刑事技术工作所涉及的范畴,在香港是由警方和政府的另外一个机构所负责。警务处仅负责一部分技术分析和检验工作,其内设的技术检验鉴定机构有鉴证科、军械法证科、法医鉴证科、炸弹处理科、警犬训练学校;另有一部分刑事技术工作则由政府化验所承担。其中,警务处鉴证科、军械法证科和政府化验所是本次参观的重点。警务处鉴证科是为香港警队和其他执法机构提供指纹鉴证及摄影服务的专业技术部门,该科主要任务是围绕指纹检验鉴定开展综合性的技术工作,包括在罪案现场寻找指模,并进行采集提取、显现处理、检验鉴定、拍照和向法庭就认定身份     

硅胶仿生指纹膜印泥痕迹特征研究

目的研究硅胶仿生指纹膜印泥痕迹特征与真实指纹印泥痕迹特征的差异,为鉴定硅胶仿生指纹膜印泥痕迹提供依据。方法首先利用液态硅胶制作仿生指纹膜,然后用仿生指纹膜和手指在相同情况下蘸取印泥,分别以轻、中、重3种力度在A4纸上垂直按压形成印泥指印,并对其拍照提取,比较仿生指纹膜印泥痕迹与真实指纹印泥痕迹的特征差异。结果仿生指纹膜印泥痕迹多见“空白”“断裂”,边缘部分不规则、凹凸不平,小犁沟宽窄程度随力度变化明显,细节特征反映不清楚;真实指纹印泥痕迹自然、纹线较连贯。结论仿生指纹膜印泥痕迹特征与真实指纹印泥痕迹特征之间存在差异,根据两者之间的特征差异可以帮助鉴别仿生指纹膜印泥痕迹。     

如何提升现场指纹的证明力

指纹曾有“证据之王”的称谓,然而在实际办案中,常常因这样或那样的问题使现场指纹很难采信。笔者从刑事科学技术人员的日常工作流程着手,以现场指纹为轴心,在勘查程序、现场三录的制作、物证送检、鉴定文书的制作、刑事技术人员的出庭作证等方面,阐述了作为一名刑事技术人员如何规范自身的日常工作,同时提出加强技术人员与侦查办案人员在工作上的渗透,以及通过提取多个现场的指纹进行串案认定,来提升现场指纹的证明力。     

我国指纹自动识别系统的发展现状和趋势

指纹自动识别系统的工作原理与功能指纹自动识别系统是用于替代刑事侦查工作中的人工指纹管理和指纹鉴定的电脑系统。该系统能全部取代指纹档案管理工作,减轻指纹管理人员的工作强度,部分完成指纹的鉴定工作。其工     

指纹鉴定的图像处理技术

随着电脑的普及以及图像处理技术的广泛应用，刑事技术领域越来越多的检验鉴定人员试图用Adobe Photoshop图像处理技术制作指纹鉴定图片，嘉兴各县市公安局技术室应用该技术出具指纹鉴定文书已有三年多的历程。可在实际应用中，无论是指纹图像处理的流程还是图像处理格式标准以及图像处理质量控制均存在一些问题。本文就指纹鉴定的图像处理技术与读者分享一些个人观点。     

指纹鉴定人员对现场指印认知能力的研究

指纹鉴定主要是解决检材指印与样本指印是否为同一人所遗留问题,其鉴定意见是法定证据形式之一,关系着被检验对象是否有犯罪嫌疑,责任重大。指纹鉴定人员根据指纹鉴定方法与标准,结合从业经验对指印进行分析与比较,并最终给出鉴定意见,在此过程中,对现场指印的分析是否客观及准确,直接影响后续比对检验、综合评断及得出的意见。本文重点针对指纹鉴定人员在指印分析阶段的细节特征选择、信息判断等问题进行研究,邀请106家指纹鉴定机构参加4组指纹的测试,实验使用一款基于网络的指纹鉴定分析系统,记录每个机构在指纹鉴定中的工作过程,并使用统计学R软件对实验数据进行统计与分析。实验结果显示,不同的指纹鉴定机构之间做出判断与评估的准确性存在一定的差异,指纹鉴定人员点取特征的稳定性、选取特征的数量与现场手印质量之间存在显著关联。     

指纹自动识别系统建设

建立公安指纹自动识别系统的紧迫性建国以来,我国各级公安机关收集、积累了近4万份刑事指纹档案,并先后采用了人工管理、人工编码和计算机半自动管理的手段和技术,使指纹档案在刑事侦查中鉴定犯罪嫌疑人以及查证无名尸体身源和亲权鉴定等工作中发挥了较大的作     

强化指纹技术工作 充分发挥“证据之首”的作用

手印是犯罪现场和嫌疑客体上出现率较高的一种犯罪痕迹,通过检验鉴定,能够起到缩小侦查范围和直接认定犯罪嫌疑人的重要作用,向来被认为是"证据之首",在侦查破案中显示其特殊的价值。在新形势下,缉私办案工作的复杂性和严峻性给刑事技术工作提出了新的更高的要求。应从将指纹工作纳入规范化、标准化、科学化轨道,不断提高指纹工作的科技含量,充分调动指纹工作者的主观能动性,重视现场勘查、密切侦技联系,并进一步做好指纹鉴定工作等方面进一步加强,最大限度地发挥指纹技术在缉私办案中的作用。     

指纹鉴定人员点取细节特征稳定性问题研究

指纹鉴定意见是指纹鉴定人员结合自身从业经验并通过一系列的检验获得的,整个指纹鉴定过程是由感性上升至理性的认知过程。在指纹鉴定过程中,指纹鉴定人员辨别现场指印中细节特征点的能力是影响指纹鉴定意见的重要因素,在获得样本指印后,对照样本指印确认现场指印中的细节特征点则直接决定着鉴定意见。考察指纹鉴定人员在检验现场指印时点取细节特征点的结果,以及获得样本指印后对现场指印细节特征的变动情况,可以分析指纹鉴定人员在不同条件下判断现场指印细节特征点的认知变化,有助于判断指纹鉴定人员在分析阶段理解现场指印特征的程度,有助于考察样本指印对指纹鉴定人员点取特征产生的影响,进而分析点取特征稳定性与指纹鉴定能力之间的关系,为指纹管理人员评估指纹鉴定人员鉴定能力提供一定帮助。本文重点针对指纹鉴定人员点取特征的稳定性进行研究,邀请106家鉴定机构对4组指印进行特征点取,使用统计学工具对点取特征的结果进行统计与分析。实验结果表明:不同机构指纹鉴定人员点取特征的稳定性存在一定的差异性;指纹鉴定人员点取特征的稳定性与现场指印质量之间存在显著关系,高质量指印鉴定过程中,指纹鉴定人员选取特征的稳定较高,且样本指印未对鉴定人员的认知能力产生影响,低质量指印鉴定过程中,指纹鉴定人员在分析阶段和比对阶段点取特征的稳定性较差,尤其在高低质量区交界处点取特征的离散程度较高;点取特征变化指数I可有效衡量指纹鉴定人员点取特征的稳定性,指纹管理人员可依据I值变化程度,评估机构或者鉴定人员的鉴定水平,进而采取相应培训措施,提高指纹鉴定过程中点取特征的稳定性,确保指纹鉴定质量。     

指印检验新方面

100多年来指印鉴定一直是犯罪侦查最有效的个体识别手段,在物证鉴定领域占据重要地位,上世纪80~90年代指印检验技术研究的重要进步更是使指印物证技术应用达到一个新的水平。最近几年指印技术研究又取得许多新进展和突破,特别是在指印显现技术和指印纹线物质成分分析方面开创了新方法和新方向,形成指印物证应用新体系,但同时在指印鉴定结论可靠性方面也出现新争议。     

绘画类试卷案件鉴定

书画类鉴定古之就有,主要集中于文物鉴定,鉴定的主要目的是判断被鉴定文物是否为某某的真迹还是赝品。此类鉴别一般都是由文物专家或考古专家进行甄别,鉴别时往往拥有供参考的真品或文献。本文通过对两份绘画类试卷是否同一人绘画的检验,从文件检验的角度鉴别绘画是否为同一人所为。     

The Effect of Image Alterations on Identification Using Palmar Flexion Creases

Palmprints are identified using matching of minutia points, which can be time consuming for fingerprint experts and in database searches. This article analyzes the operational characteristics of a palmar flexion crease (PFC) identification software tool, using a dataset of 10 replicates of 100 palms, where the user can label and match palmar line features. Results show that 100 palmprint images modified 10 times each using rotation, translation, and additive noise, mimicking some of the characteristics found in crime scene palmar marks, can be identified with a 99.2% genuine acceptance rate and 0% false acceptance rate when labeled within 3.5 mm of the PFC. Partial palmprint images can also be identified using the same method to filter the dataset prior to traditional matching, while maintaining an effective genuine acceptance rate. The work shows that identification using PFCs can improve palmprint identification through integration with existing systems, and through dedicated palmprint identification applications.     

毒物分析在侦查破案中的应用

毒物分析主要研究涉及法律问题的生物检材或其他检材中毒物的分离与鉴定,能查明中毒原因,澄清案件性质,在死因鉴定中是不可或缺的关键环节。近年来,随着毒物检验鉴定技术的不断发展,毒物分析技术手段已在侦查破案中发挥着越来越重要的作用。本文报道了两起中毒死亡的案例,通过运用气相色谱-质谱联用技术,在关键检材中分别检出特丁硫磷和一氧化碳目标物质,后结合现场勘查等材料成功侦破,还原了案件真实面目,突显了毒物分析技术在服务和支撑实战中发挥的决定性作用。     

印文鉴定相关问题探讨——高仿真印文鉴定

当前,与印文鉴定相关的并在鉴定实践中经常遇到的新问题和难点问题有高仿真印文的鉴定、变造印章问题、利用真实印文变造文件、同版印章印文、朱墨时序等,本文就高仿真印文的鉴定进行了系统阐述,介绍了各种高仿真印文,包括各种高仿真印章的盖印印文、复制印文、转印印文的伪造手段及其特点,并提出了高仿真印文的鉴定思路和要点。     

Identifying Counterfeit Cigarettes Using Environmental Pollen Analysis: An Improved Procedure*

Traditional pollen preparation techniques provide clear residues for pollen identification; however, such methods are time-consuming, requiring repeated centrifugation, heating, and digestion with high-concentration hazardous chemicals. Tobacco leaves can effectively trap environmental pollen due to hairy surface and terpene-rich exudates. A new tobacco sample processing method was developed by using different extraction chemistry with surfactant. Marlboro Gold cigarettes were employed as model samples for method development. Parameters critical for pollen extraction, which include number of cigarette sticks used, extraction solution, and extraction temperature, were optimized. By using 1% dishwashing detergent to treat three cigarettes at room temperature, the improved method was able to recover sufficient pollen for microscopic analysis in three repeated centrifuge-washing steps and omit hazardous chemicals involved in traditional methods. We focused on the pollen of common ragweed (Ambrosia artemisiifolia), a plant native to North America, as an indicator to differentiate genuine and counterfeit U.S. brand cigarettes. Results from analyzing randomly purchased genuine (authenticated by forensic examination) and known counterfeit Marlboro Gold provided by law enforcement revealed that a significant amount (39%) of Ambrosia were consistently present in all genuine samples, while counterfeit contained none or only trace count. Similar results were found in other counterfeit U.S. brand cigarettes (all seized in the U.S.) involved in this study as well. Lack of Ambrosia in cigarette strongly indicates the product was not originated in the United States.     

A Prototype of Mathematical Treatment of Pen Pressure Data for Signature Verification

A prototype using simple mathematical treatment of the pen pressure data recorded by a digital pen movement recording device was derived. In this study, a total of 48 sets of signature and initial specimens were collected. Pearson's correlation coefficient was used to compare the data of the pen pressure patterns. From the 820 pair comparisons of the 48 sets of genuine signatures, a high degree of matching was found in which 95.4% (782 pairs) and 80% (656 pairs) had rPA > 0.7 and rPA > 0.8, respectively. In the comparison of the 23 forged signatures with their corresponding control signatures, 20 of them (89.2% of pairs) had rPA values < 0.6, showing a lower degree of matching when compared with the results of the genuine signatures. The prototype could be used as a complementary technique to improve the objectivity of signature examination and also has a good potential to be developed as a tool for automated signature identification.     

The Notion of Consent to Sexual Activity for Persons with Mental Disabilities

This paper seeks to examine the notion of consent to sexual activity as it is applied to situations involving persons with mental disabilities both by both medical professionals and the law. This will be achieved by analysing sexuality and consent through the lens of disability theory and subsequently by including feminist theories on the notion of consent and of sexual activity generally where this serves to assist in coming to a genuine assessment of the nature and existence of consent to sexual activity for persons with mental disabilities. It is concluded that in order to ensure that genuine substantive consent to sexual activity on the part of the persons with mental illnesses is accurately assessed at both a civil and criminal level, a fusion of both feminist and disability theory into such assessments and adjudications is vital.     

Establishing of chemical composition of printing ink

The subject of the examinations was primarily court tax marks of 50 and 200 PLN, which were suspected not to be genuine. Both inks on the questioned marks as well as comparative genuine marks and inks sent by the manufacturer were analyzed. No information about their chemical composition was available from manufacturer. In the examinations, infrared (IR), visible, X-ray fluorescence, and Raman spectrometry were used. The examinations showed that inks and glue on the marks of both values were the same as samples of those sent by the manufacturer. Discrepancies in some results were observed probably due to contamination, that is, an accidental presence of the foreign substance on the surface (e.g., sweat, saliva while sticking the marks to the surface or physical handling of the documents). It was concluded that there are original (genuine) court tax marks.