Preparation of Disappearing Inks and Studying the Fading Time on Different Paper Surfaces

Abstract: Disappearing inks have been used in different fields, but it may be abused in forgery and counterfeiting. This research was conducted on the preparation of disappearing inks using different concentrations of thymolphthalein, phenolphthalein, and their mixture. The prepared inks were applied to different types of handwriting papers. It was found that the handwriting stability increased by increasing thymolphthalein, phenolphthalein, or alkali concentration, but in the case of using 4 mL of 1 normal (N) NaOH, the handwriting stability of phenolphthalein and its mixture inks decreased. Deciphering of the faded handwriting was evaluated by different methods; using optical deciphering, the faded handwriting did not respond to the different light sources. All the faded handwriting was visible when treated with alkaline solution. There was no change in the faded handwriting when heated to 100°C; phenolphthalein and mixture inks containing 0.5 mL of 1 N NaOH became red when only Azhar and Xerox papers were heated to 150°C.     

运用笔迹检验侦破案件的几点思考

运用笔迹检验手段侦破案件,是通过嫌疑人刻画、收集样本、检验鉴定等专门方法认定犯罪嫌疑人的完整过程。在近年来发生的破坏铁路交通设施案的侦破实践中,通过现场所留文字分析刻画犯罪嫌疑人。为划定侦查范围提供了依据。破坏交通设施案笔迹样本的收集主要存在以下难点：案前样本不易收集,案后样本收集的质量参差不齐,样本收集对象不配合,个别侦查人员责任心和能力不强。     

论病理因素对笔迹的影响

人的书写活动,是极端复杂与微妙的。它是由脑、身、肩、臂、肘等多个器官联合、协调动作完成的,各部位发挥的作用不一样,各有各的机理、机制。在正常情况下,缺少任何一项就不能完成书写活动,而其中任何一项一旦发生病变,写出的字也要发生变化。研究这种变化的特点及成因,对笔迹鉴定很有裨益。     

样本质量决定着笔迹鉴定工作的成败

物证笔迹字少、笔画简单是当前笔迹鉴定中较为突出的问题 ,同时 ,物证笔迹中存在伪装摹仿和涂改添加的可能性较大 ,这就要求用于鉴定比对的笔迹样本在数量和质量上更加充分可靠 ,能够满足笔迹鉴定的需要。样本质量的好坏直接关系着笔迹鉴定工作的成败 ,对笔迹样本的要求以及具体的收集提取方法和操作技巧所作出研究和总结 ,对保证笔迹鉴定工作的顺利进行具有重要意义。     

论笔迹鉴定差异点的评断

书写习惯的自身同一是包含了差异的同一,而不同人书写习惯的差异则是包含了共性的非本质差异,因而在通过未知与已知笔迹比较检验来实现书写习惯的同一认定时必须科学评断差异的性质,否则同一认定鉴定意见缺乏科学可靠性。在对笔迹鉴定意见的质证中,对差异点的认识和性质的判断成为争议的焦点,而且成为评价鉴定活动是否严谨和科学,以及鉴定意见是否可以采信的主要依据之一。而今面对证据科学对笔迹鉴定意见的挑战,除严格笔迹鉴定的条件外,必须从理论上完善对笔迹鉴定差异点的评断方法,明确评断的规则,从而保证鉴定意见的科学可靠性。     

横式行草书设计签名笔迹检验探析

随着社会的发展,在各类经济、刑事及民事纠纷案件中涉及对设计签名进行鉴定的案件呈逐年上升趋势。横式行草书设计签名作为一种常见的特殊形式的签名,具有其独特的特点,对此类设计签名笔迹的检验方法还有待充实和完善,为成功地完成对设计签名的检验鉴定任务,总结横式行草书设计签名笔迹的特点,并对其检验依据及检验方法等问题进行分析阐述,以供广大同行共同研究探讨。     

Identification of the Class Characteristics in the Handwriting of Polish People Writing in English

Abstract: An investigation was carried out to identify the class characteristics of Polish people writing in English and to specifically identify those characteristics that separate Polish handwriting from English handwriting. In the first stage, 40 Polish and 40 English handwriting samples were collected and systematically examined. In total, 31 features were identified that occurred in ≥25% of the Polish handwriting samples and therefore considered class characteristics. Of these, chi‐square analyses identified 21 class characteristics that occurred significantly more in Polish compared to English handwriting. Twenty‐one of the class characteristics in the Polish handwriting had similar constructions to the copybook pattern thus supporting the theory that class characteristics frequently stem from the taught writing system. In the second stage, an algorithm was developed using seventeen of the class characteristics that successfully discriminated between a further 13 Polish and 12 English handwriting samples.     

Forensic Document Examiners’ Skill in Distinguishing Between Natural and Disguised Handwriting Behaviors

Abstract: Disguised handwriting is problematic for forensic document examiners (FDEs) and attracts higher misleading and inconclusive rates on authorship opinions than does genuine writing (Found B, Rogers D, International Graphonomics Society, 2005). There are currently no published empirical data on FDEs’ expertise in distinguishing between natural and disguised writing behavior. This paper reports on the skill of FDEs for determining the writing process of 140 pairs of natural and disguised writings and compares their results with those of a control group of laypeople. A significant difference was found between the examiner and lay group. FDEs’ expertise is characterized by their conservatism, where FDEs express a higher proportion of inconclusive opinions (23.1% for FDEs compared to 8.4% for the control group). This leads to the FDEs expressing a smaller percentage of misleading responses when calling writings as either naturally written or disguised (4.3% for FDEs compared with 12.2% for the control group).     

Use of an Automated System to Evaluate Feature Dissimilarities in Handwriting Under a Two-Stage Evaluative Process*†

The two-stage evaluative process is an established framework utilized by forensic document examiners (FDEs) for reaching a conclusion about the source(s) of handwritten evidence. In the second, or discrimination, stage, the examiner attempts to estimate the rarity of observations in a relevant background population. Unfortunately, control samples from a relevant background population are often unavailable, leaving the FDE to reach this determination based on subjective experience. Automated handwriting feature recognition systems are capable of performing both feature comparison and discrimination, yet these systems have not been subjected to empirical validation studies. In the present study, we repurposed a commercially available automated system to generate empirical distributions for ranking feature dissimilarity scores among pairs of handwritten phrases. The blinded results of this automated process were used to survey an international cohort of 36 FDEs regarding their strength of support for same- and different-writer propositions. The survey served to cross-validate FDE decision-making under the two-stage approach. Results from the survey demonstrated a clear pattern of response consistent with ground truth. Predictive regression analyses indicated that the automated feature dissimilarity scores and the log of their cumulative distribution functions accounted for 72% of the variability in FDE opinions. This study demonstrated that feature dissimilarity scores acquired using automated processes and their distributions are closely aligned with FDE decision-making processes supporting the heuristic value of the two-stage evaluative framework.     

复写笔迹变化规律的实验研究

目的：研究复写笔迹的变化规律,探讨复写笔迹特征价值。方法：从书写压力、品牌、承受纸张和不同联四个因素对普通复写纸与无碳复写纸进行考查,统计、分析200余份复写笔迹变化规律。结果：不同品牌之间复写笔迹的变化基本不明显,其他三因素则变化都较为显著。同时提出在对复写笔迹进行检验时,特别是综合评断时要细致分析复写笔迹变化产生的可能原因,才能作出更为可靠和可信的鉴定意见。