笔迹样本中的五种假象不容忽视

研究笔迹样本的一些特征,它既不是代表书写人的书写习惯,也不是书写人笔迹特征的本来面目,对此称之为特征假象。本文拟就对笔迹样本中产生假象的原因、表现形式(除意外产生)进行了研究,并对识别的办法进行探讨。     

专业性练习摹仿签名笔迹鉴定的实验研究

目的本文通过实验对具有一定笔迹鉴定专门知识与不具备笔迹鉴定专门知识的人的练习摹仿签名笔迹进行实验分析研究。方法对两类人在练习的不同阶段形成的练习摹仿签名笔迹特征的一般状态表现,以及对其笔迹特征的形成、变化原因、鉴定价值分别进行了论述,并总结出其变化规律。结果为不同种类的练习摹仿签名笔迹的鉴定提供一定的识别和特征分析、评断的参考依据。     

Simulation Detection in Handwritten Documents by Forensic Document Examiners

This study documents the results of a controlled experiment designed to quantify the abilities of forensic document examiners (FDEs) and laypersons to detect simulations in handwritten documents. Nineteen professional FDEs and 26 laypersons (typical of a jury pool) were asked to inspect test packages that contained six (6) known handwritten documents written by the same person and two (2) questioned handwritten documents. Each questioned document was either written by the person who wrote the known documents, or written by a different person who tried to simulate the writing of the person who wrote the known document. The error rates of the FDEs were smaller than those of the laypersons when detecting simulations in the questioned documents. Among other findings, the FDEs never labeled a questioned document that was written by the same person who wrote the known documents as “simulation.” There was a significant statistical difference between the responses of the FDEs and layperson for documents without simulations.     

一起練习记忆摹仿签名笔迹的鉴定与启示

本文通过对一起检验鉴定案例的分析,提出练习记忆摹仿的概念,并对该类案件的检验鉴定,总结出十点启示。     

个人言语风格的司法鉴定

言语是运用语言表达思想的结果 ,书写的文字 (笔迹 )是它借以存在的物质基础 ,笔迹鉴定和言语风格鉴定成为统一于文书鉴定中的两个有机组成部分。个人之间不同的言语风格、语言特征 ,主要表现在词汇、句式、句法等语言材料和表达方式的各个要素 ,以及言语内容与个人属性和案件情况的关系等诸方面。对案件中涉及的书面言语材料个人言语风格的鉴定 ,必须将言语、笔迹与具体的案件情况和其它物证结合起来进行综合判断。     

笔迹检验中笔迹起收笔特征稳定与变化的研究

笔迹起收笔的位置特征、起收笔的动作形态特征和起收笔的笔力特征等三个方面的稳定与变化 ,在笔迹检验中具有重要作用。对其进行研究 ,主要是为了更好地掌握起笔与收笔在书写过程中的表现 ,从而提高起收笔特征在笔迹检验中的利用率     

滚珠型签字笔笔痕特征的实验研究

目的归纳总结滚珠型签字笔笔痕特征的分类,为笔迹鉴定人正确使用此类笔迹特征提供科学的参考依据。方法本研究采用科学实验的方法,对20人使用不同品牌的三支签字笔书写的笔迹进行了观察与分析。结果同一人使用不同的签字笔、不同人使用同一支签字笔和不同人使用不同的签字笔书写所形成的笔痕现象具有相同的表现。结论签字笔笔痕特征只是众多笔迹特征当中的一种,不能单独依据此类特征出具鉴定结论。     

Using automated comparisons to quantify handwriting individuality

The proposition that writing profiles are unique is considered a key premise underlying forensic handwriting comparisons. An empirical study cannot validate this proposition because of the impossibility of observing sample documents written by every individual. The goal of this paper is to illustrate what can be stated about the individuality of writing profiles using a database of handwriting samples and an automated comparison procedure. In this paper, we provide a strategy for bounding the probability of observing two writers with indistinguishable writing profiles (regardless of the comparison methodology used) with a random match probability that can be estimated statistically. We illustrate computation of this bound using a convenience sample of documents and an automated comparison procedure based on Pearson's chi-squared statistic applied to frequency distributions of letter shapes extracted from handwriting samples. We also show how this bound can be used when designing an empirical study of individuality.     

Handwriting evidence evaluation based on the shape of characters: application of multivariate likelihood ratios

A novel Bayesian methodology has been developed to quantitatively assess handwriting evidence by means of a likelihood ratio (LR) designed for multivariate data. This methodology is presented and its applicability is shown through a simulated case of a threatening anonymous text where a suspect is apprehended. The shape of handwritten characters a, d, o, and q of the threatening text was compared with characters of the true writer, and then with two other writers, one with similar and one with dissimilar characters shape compared to the true writer. In each of these three situations, 100 draws of characters were made and the resulting distributions of LR were established to consider the natural handwriting variation. LR values supported the correct hypothesis in every case. This original Bayesian methodology provides a coherent and rigorous tool for the assessment of handwriting evidence, contributing undoubtedly to integrate the field of handwriting examination into science.     

Forensic identification science evidence since Daubert: Part II--judicial reasoning in decisions to exclude forensic identification evidence on grounds of reliability

Many studies regarding the legal status of forensic science have relied on the U.S. Supreme Court's mandate in Daubert v. Merrell Dow Pharmaceuticals Inc., and its progeny in order to make subsequent recommendations or rebuttals. This paper focuses on a more pragmatic approach to analyzing forensic science's immediate deficiencies by considering a qualitative analysis of actual judicial reasoning where forensic identification evidence has been excluded on reliability grounds since the Daubert precedent. Reliance on general acceptance is becoming insufficient as proof of the admissibility of forensic evidence. The citation of unfounded statistics, error rates and certainties, a failure to document the analytical process or follow standardized procedures, and the existence of observe bias represent some of the concerns that have lead to the exclusion or limitation of forensic identification evidence. Analysis of these reasons may serve to refocus forensic practitioners' testimony, resources, and research toward rectifying shortfalls in these areas.