利用真签名伪造文书的识别与检验

通常情况下,绝大多数人认为,签名真伪决定了文书真伪.司法鉴定实际工作中,事实上签名真伪与文书真伪并不是等同关系.利用真签名伪造文书有许多方法.由于签名真是书写人的笔迹,因此在利用真签名伪造文书的实际鉴定中,鉴定人往往忽视系统检验,从而作出不符合客观实际的鉴定结论.在检验中,应充分根据利用真签名伪造文书不同方法出现的不同特点,综合运用案情分析法、细节特征比较法、图像软件分析法、仪器检验法、系统检验法进行检验.在检验过程中,还应注意受理案件时的材料是否为原件;案件情况中双方当事人矛盾的焦点;签名是真签名还是摹仿签名.     

签名字迹的检验

签名字迹是指在公私文书上签署自己姓名而形成的文书笔迹符号。文书上的签名是文书真实性和有效性的标志和证明,于是伪造签名也就成为不少违法犯罪分子的惯用伎俩,尤其在经济犯罪案件中的伪造签名更多。也正因为如此,为了从法律上明确文书签名的真实性和有效性,确定文书中可疑签名字迹的真伪和书写人,就产生了签名字迹鉴定。1真实签名字迹的特点(1)字数少,动作的规律性表现不充分。签名通常是两个字、三个字或四个字,相同单字、组成部分、笔画等整体特征的重复率低,因此,书写习惯暴露不充分,书写规律不易掌握。(2)签名字迹具有相对的不稳定…     

利用复写方式窃取签名伪造文件的鉴定

当前，在民事诉讼及各种经济类犯罪案件中伪造文书证据的情况屡见不鲜，手段也日益更新。利用他人真实签名伪造文件就是较为常见的一种造假手段，如案件当事人或犯罪嫌疑人利用他人真实签名在原有文件条款的基础上进行添加；消褪原有内容字迹再书写新的内容；将文件裁切后在空白处书写内容；利用数字化成像方法采集签名，     

利用真实印文签名变造欠条的系统鉴定

民事诉讼中当事人利用真实印文、签名伪造证据的情况日益增多,增加了鉴定的难度,本文以实际案件为例,运用系统鉴定法,从纸张、印文真伪及盖印时间、打印字迹、手写字迹、比对样本、重视案情调查了解等多个角度对如何鉴定此类案件做了经验性的总结和阐述。     

浅析摹仿签名笔迹鉴定

摹仿签名笔迹检验是笔迹检验的难点,认定签名摹仿人更是难中之难;笔者通过正确确定签名笔迹的真伪,从签名笔迹的概貌特征和细节特征之中运用辩证的观点正确认定摹仿人。     

字间组合特征在鉴定签名笔迹中的应用

字间组合特征，指词和固定词组中的整体组合及各个字间的大小、比例、搭配关系特征。其具有较强的稳定性，特别是在签名、数字、常用词等方面，更好地体现了书写人的书写习惯。笔者在鉴定几起签名案件时，通过利用其字间组合特征，成功出具了正确的鉴定结论。下面笔者试就字间组合特征在鉴定签名笔迹中的应用作一简析。在实际工作中我们遇到的签名情况比较多，主要有以下几种情况：调查笔录、调解书等文书的签名、银行存（取）款凭条签名、财务报销时报销人、批准人签名以及合同书、其他票据上的签名，等等。在这些签名鉴定案件中，有的是对…     

再谈少量字迹伪装笔迹的检验

少量字迹伪装笔迹的检验一直是困扰基层文检鉴定员的一个难题.最近笔者成功地鉴定了一宗假冒他人签名的案件.一名外地女子冒用他人身份,办理了一张深圳市的身份证,送检单位要求鉴定“身份证申领表”中经办人“罗卫龙”的签名.该案在少量字伪装笔迹检中具有较强的代表性,通过对这起案件的检验,笔者受到不少启发,现谈谈自己的体会,1认真分析检材,全面利用可供检验的信息.全面分析检材是鉴定工作的首要环节,一份检材不仅记载着笔迹方面的信息,而且还包含着其它多方面的信息,如纸张、书写材料、印章等,这方方面面的信息相互关联,互相印证,将其综合起来利用,不仅对案件本身而且对笔迹检验也有很大的帮助.在日常工作中,送检单位往往只对鉴定人员提出单一的检验要求,受此影响,鉴定人员的思维很容易受到限制,从而忽略其它方面的检验,失去更多的检验信息.因此,在少量字迹案件的笔迹检验中,首先要认真分析检材,确定弄清检材中各项内容与案件的关系,从多角度、全方位提出问题,解决问题,指导我们进行下一步的检验工作对上述案例,我们做了表格的真伪、墨水的材质、印章的真伪、印泥是否与该单位的一致、印文与书写字迹的先后顺序、及压痕、表格内所记载内容的真伪、所有笔迹是否为一人书写等方面的检验:     

正确把握朱墨时序鉴定的几个基本环节

在文书检验中,朱墨交叉顺序的判定一直是一个常见、重要的内容,对于鉴别文书的真伪具有决定性的重要意义。近年来,在科研和检案实践中发现,正确区分印章印文与书写文字的先后顺序,应掌握以下几个基本环节:有统一的技术规范作指导;检验设备应当满足技术规范要求;对字迹和印文色料与纸张结合方式进行检验;检验方法不能单一,应用多种方法相互对照应证;客观评价阳性反应的出现率和排除假阳性反应的干扰。     

摹仿签名字迹检验的点滴体会

近几年,江苏省人民法院受理检验的各类案件不断增多,仅1999年收案数就较1998年收案数增加62%,2002年1月至4月收案数已达1999年全年收案数54%。案件类别繁多,检验范围较广,其中以原、被告双方签订合同、协议及债务等经济纠纷案件较为突出,这些案件往往又是原、被告双方对某一方签名的真伪性争执不休,使得基层法院不能及时、顺利地审理。因此,如何确保签名字迹检验结论的正确,更好地服务于司法,是法院系统文检工作者的任务之一。为了进一步提高对签名字迹的检验水平,我们针对1999年受理检验且结论正确的105起签名字迹案件作了回顾性分析,其中…     

浅谈签名字迹检验应注意的问题

当前，在经济犯罪领域有关模仿他人笔迹、冒充他人签名的案件越来越多。由于签名字迹检验存在可供检验的字迹字数少，相同单字、相同结构的文字较少重复出现，以及个人书写的多样性和复杂性等特点，就使得案件中的检材签名字迹真假难辨。还有的嫌疑人为了模仿他人字迹，进行长时间的反复练习，甚至达到连被模仿人都不能确定检材中的签名是否为本人所写。在此，笔者结合检验经验，对签名字迹案件在受理、检验和鉴定三个阶段应注意的问题谈一点体会。     

Investigating forensic document examiners’ skill relating to opinions on photocopied signatures

Many forensic document examiners are hesitant to express authorship opinions on photocopied handwriting as the photocopying process results in less feature information than original writing. This study aimed to test the accuracy of 15 examiners' opinions regarding whether photocopied questioned signatures were genuine or simulated. Each examiner received the same set of original signature exemplars, from one individual, and a set of eighty questioned photocopied signatures comprising of genuine and simulated signatures. The overall misleading (error) rate for the grouped examiners' opinions was 0.9% providing strong evidence that examiners can make accurate observations regarding the authorship of non-original handwriting.     

Forensic handwriting examiners' expertise for signature comparison

This paper reports on the performance of forensic document examiners (FDEs) in a signature comparison task that was designed to address the issue of expertise. The opinions of FDEs regarding 150 genuine and simulated questioned signatures were compared with a control group of non-examiners' opinions. On the question of expertise, results showed that FDEs were statistically better than the control group at accurately determining the genuineness or non-genuineness of questioned signatures. The FDE group made errors (by calling a genuine signature simulated or by calling a simulated signature genuine) in 3.4% of their opinions while 19.3% of the control group's opinions were erroneous. The FDE group gave significantly more inconclusive opinions than the control group. Analysis of FDEs' responses showed that more correct opinions were expressed regarding simulated signatures and more inconclusive opinions were made on genuine signatures. Further, when the complexity of a signature was taken into account, FDEs made more correct opinions on high complexity signatures than on signatures of lower complexity. There was a wide range of skill amongst FDEs and no significant relationship was found between the number of years FDEs had been practicing and their correct, inconclusive and error rates.     

Visual attention and expertise for forensic signature analysis

Eye tracking was used to measure visual attention of nine forensic document examiners (FDEs) and 12 control subjects on a blind signature comparison trial. Subjects evaluated 32 questioned signatures (16 genuine, eight disguised, and eight forged) which were compared, on screen, with four known signatures of the specimen provider while their eye movements, response times, and opinions were recorded. FDEs' opinions were significantly more accurate than controls, providing further evidence of FDE expertise. Both control and FDE subjects looked at signature features in a very similar way and the difference in the accuracy of their opinions can be accounted for by different cognitive processing of the visual information that they extract from the images. In a separate experiment the FDEs re-examined a reordered set of the same 32 questioned signatures. In this phase each signature was presented for only 100 msec to test if eye movements are relevant in forming opinions; performance significantly dropped, but not to chance levels indicating that the examination process comprises a combination of both global and local feature extraction strategies.     

An insight into forensic document examiner expertise for discriminating between forged and disguised signatures

It has previously been shown that forensic document examiners (FDEs) have expertise in providing opinions about whether questioned signatures are genuine or simulated. This study extends the exploration of FDE expertise by evaluating the performance of eight FDEs and 12 control subjects at identifying signatures as either forgeries or the disguised writing of a specimen provider. Subject eye movements and response times were recorded with a Tobii 1750 eye tracker during the signature evaluations. Using a penalty scoring system, FDEs performed significantly better than control subjects (t = 2.465, p = 0.024), with one FDE able to correctly call 13 of the 16 test stimuli (and three inconclusive calls). An analysis of eye movement search patterns by the subjects indicated that a very similar search strategy was employed by both groups, suggesting that visual inspection of signatures is mediated by a bottom up search strategy. However, FDEs spent greater than 50% longer to make a decision than the control group. The findings are suggestive that for some stimuli FDEs can discriminate between forgeries and disguises, and that this ability is due to a careful inspection and consideration of multiple features within a signature.     

Are expert penmen better than lay people at producing simulations of a model signature?

Although forensic signature examination is considered to be an identification science, it is a theoretical possibility that an individual may learn to forge another person's signature that is free from indications of simulation behaviours. This proposition was tested in a signature blind trial that was administered to 42 forensic handwriting examiners (FHEs). Participants expressed opinions on the authorship of 100 questioned signatures. The questioned signatures comprised a mixture of genuine, disguised and simulated signatures. Calligraphers formed part of the population of individuals who provided simulated signatures for the trial. A total of 3100 opinions were expressed of which 1254 were correct, 224 misleading and 1622 were inconclusive. Of the opinions expressed regarding the simulated signatures, the misleading score for the calligraphers' forgeries were approximately four times that of the lay persons' forgeries. These results provide strong evidence in support of the proposition that calligraphers are more skilled at simulating signatures than are lay people and can produce forgeries that some FHEs have difficulty detecting.     

The probative character of Forensic Handwriting Examiners' identification and elimination opinions on questioned signatures

This 5-year study investigated the character of Forensic Handwriting Examiners' (FHEs) authorship opinions on questioned signatures through the medium of blind validation trials. Twenty-nine thousand eight hundred and eleven authorship opinions were expressed by FHEs on trial kits comprising randomized questioned genuine signatures (written by the specimen writer), disguised signatures (written by the specimen writer) and simulated signatures (not written by the specimen writer). Results showed that, as a group, FHEs were significantly more confident at identifying writers' genuine signatures than identifying writers' disguised signatures or eliminating specimen writers from having authored simulated signatures. It is proposed that the difference in FHE confidence arises from the difficulty they have in deciding which alternative authorship explanation accounts for perceived combinations of similar and dissimilar features between specimen and questioned signatures.     

The probative character of Forensic Handwriting Examiners’ identification and elimination opinions on questioned signatures

This 5-year study investigated the character of Forensic Handwriting Examiners’ (FHEs) authorship opinions on questioned signatures through the medium of blind validation trials. Twenty-nine thousand eight hundred and eleven authorship opinions were expressed by FHEs on trial kits comprising randomized questioned genuine signatures (written by the specimen writer), disguised signatures (written by the specimen writer) and simulated signatures (not written by the specimen writer). Results showed that, as a group, FHEs were significantly more confident at identifying writers’ genuine signatures than identifying writers’ disguised signatures or eliminating specimen writers from having authored simulated signatures. It is proposed that the difference in FHE confidence arises from the difficulty they have in deciding which alternative authorship explanation accounts for perceived combinations of similar and dissimilar features between specimen and questioned signatures.     

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。     

再看摹仿签名笔迹鉴定

由于签名笔迹字数少、可摹仿性强的特点,长期以来,摹仿签名笔迹鉴定始终是笔迹鉴定的难点。笔者从不同类型的摹仿方法出发,讨论不同方法下摹仿签名笔迹的特点,总结其特征规律。同时要重视笔迹鉴定过程中了解相关案情,为识别是否存在摹仿现象提供线索。在此基础之上,对比摹仿签名笔迹特征的变化规律,并从摹仿签名笔迹特征反映构成方面系统性地进行鉴定,鉴别是否存在摹仿签名的情况。通过撰写此文,以期对摹仿签名笔迹鉴定实务具有借鉴意义。     

系统鉴定方法在朱墨时序鉴定中的应用

朱墨时序鉴定是通过对印字交叉部位的检验,得出的印字先后顺序的判断。朱墨时序鉴定是文件鉴定的重要组成部分,它往往是判定文件物证真实性的重要依据之一。任何文件物证都是一个由多个要素组成的文件系统。通过介绍系统鉴定方法的原理、方法,以鉴定实践说明其在朱墨时序鉴定中的三种作用,同时也强调各种检验方法的综合运用。提倡在朱墨时序鉴定中,应运用系统鉴定方法,更加准确的把握印字交叉部位的表观特征,从而提高朱墨时序鉴定的准确性。