Examination of the Sequence between Laser Printing and Rollerball Pen Writing Without an Intersecting Stroke

Examining the sequences of printing and writing is a significant method of determining the authenticity and validity of documents. Forensic document examiners have extensively studied crossing lines, which has produced useful information. However, the sequence for laser printing and rollerball pen writing without crossing strokes has not been studied. To solve this problem, volunteers were invited to write characters on A4 paper with different rollerball pens using two sequences. Four laser printers applied print to these sheets, and the materials were examined using an Optem A-Zoom2 video tomography microscope. Consequently, distinguishing features were noted between the materials produced in both sequences. These features might provide a scientific basis for accurately determining the sequence between laser printing and rollerball pen writing in the absence of intersecting strokes.     

无交叉笔画状态下激光打印文字与中性笔书写文字形成时序的实验研究

目的探索无交叉笔画状态下激光打印文字与中性笔书写文字的时序特征及变化规律,以求运用于案件检验。方法以两种不同时序,请5名志愿者分别执不同中性笔在120张A4纸张上书写文字,并使用4台不同型号激光打印机打印文字,再运用奥博视频层晰显微镜对实验样本进行放大观察。结果证实在两种时序条件下制作的实验样本之间存在诸多差异性特征。结论这些差异性特征为准确判定无交叉笔画状态下激光打印文字与中性笔书写文字的时序提供了基础实验依据。     

写字机器人伪造签名字迹的鉴别

目的通过实验研究使用写字机器人伪造的签名字迹特征,减小文件检验鉴定中的错判风险。方法以真实书写字迹为模板、使用市面上主流款式的写字机器人执不同种类书写笔进行书写,通过直接观察、显微观察、反射变换成像(RTI)方法观察等方式比对手写字迹和机器人书写字迹的差异,归纳写字机器人伪造字迹的主要特征,总结出有效的检验鉴别方法。结果通过研究发现写字机器人伪造签名笔迹的特点主要有起收笔为顿压笔,笔画出现细微的抖动歪曲现象,整体笔画笔压均匀,运笔生硬无笔势等。结论目前写字机器人伪造签名字迹与真实手写字迹还有一定差异,使用反射变换成像(RTI)方法观察能达到较好的检验效果。     

书写时间确定技术的国内现状与发展

综述了书写时间确定技术在国内的现状及最新发展,主要从三方面进行了介绍:水溶性书写时间确定技术;圆珠笔油墨书写时间确定技术;间接确定文件的书写时间方法。     

Determination of the Chronological Order of a Laser Printing and Gel Pen Writing Without any Crossing Strokes

Laser printers and writing instruments are being exploited by the forgers to produce fabricated documents. They often produce such documents by appending genuine signature on a blank sheet and later printing on it. Often these fabricated documents do not contain intersection of strokes and may pose a difficulty to forensic document examiners in analyzing cases related to such documents. Keeping in mind the limited research work done on nonintersecting strokes, the present study has been conducted with an aim to determine the sequence of nonintersecting strokes of gel pens and laser printers. Three hundred samples of nonintersecting strokes of gel pen ink and laser printing were prepared. Of these 300, 150 had laser-printed text below the gel pen strokes and the remaining 150 were prepared with gel pen stokes below the laser-printed text. The samples have been analyzed using Nikon SMZ 800N stereomicroscope. Three micro-conformation features, that is, pattern of toner distribution, ink distribution, and fiber distribution have been observed in the samples. The results demonstrate the successful establishment of sequence of nonintersecting strokes in case of gel pen and laser-printed documents by the determination of micro-conformation features.     

Application of Video Spectral Comparator (absorption spectra) for establishing the chronological order of intersecting printed strokes and writing pen strokes

The sequence of intersecting strokes of laser printers (black, blue, red and green) and typewriter ink (black) with the strokes of gel pen ink, ballpoint pen ink and fountain pen ink (black, blue, red and green) has been determined by studying their absorption spectra. The absorption spectra have been generated for each of the two pure inks (i.e. A and B) and points of their intersections (i.e. A over B and B over A) by using Video Spectral Comparator (VSC-2000-HR). The study was carried out with an assumption that the peak characteristics of spectra from the point of intersection should correspond to the peak characteristics of pure ink which was executed later. It was observed that the absorption spectrum of intersection corresponds with either the laser printer or the typewriter ink stroke, whether these strokes were executed earlier or later than the writing instrument strokes. As the results obtained from the study were negative, the FDEs are advised against the practice of this technique in the examination of the sequence of intersecting strokes for these specified inks.     

书写方向对笔顺和笔径的影响

以反犬旁、山字为目标字,收集了1178份有效笔迹样本,其中反犬旁常见笔顺样本954份,当用常见笔顺书写反犬旁时,第一个撇笔有正反2种笔径,分性别检验山字笔顺与反犬旁第一撇的笔径的相关性,用似然比测定其相关程度。字的书写方向因子可以解释山字笔顺与反犬旁笔顺、笔径相关的结果,研究结果支持了书写能力结构的因子假说。     

书写材料的无损检验系统研究

本研究运用显微分光光度仪、文件检验仪和傅立叶变换拉曼光谱仪三种方法,分别对在中国市场上收集的不同厂家、牌号、型号的35种黑墨水、20种蓝黑墨水、22种蓝墨水、49种黑色墨水笔、30种蓝色墨水笔、45种黑色圆珠笔、和50种蓝色圆珠笔等七组样品进行非破坏检验。结果表明:(1三种非破坏检验方法都能单独对七组样品进行不同程度的鉴别,区分率在50%—94.4%之间;(2)三种方法联用后对黑墨水、蓝黑墨水、蓝墨水、黑色墨水笔、蓝色墨水笔、黑色圆珠笔和蓝色圆珠笔的区分率可分别提高到93.4%、97.3%、99.1%97.2%、97.2%、95.6%和91.8%。通过三种非破坏检验方法的联用,证明它们之间有较强的互补性,最大限度地提高了检验效应,可建立系统的非破坏检验方法。     

Recent developments in writing sequence determination

Two modifications of the Igoe-Reynolds lift technique for examination of line margins to determine the sequence of intersecting ball-point pen strokes are proposed. One for handwriting-typewriting intersections and the other extending the lift technique to ball-point pen writings of some age that are otherwise insensitive to the lift efforts.Attention is also directed to the increased usefulness of spectular light reflection examination resulting from changes in writing materials and instruments, particularly as applied to handwriting-typewriting sequence determination. An inexpensive, readily improvised vertical illuminator is described suitable for use with stereomicroscopes and cameras.     

Sequencing the intersections of printed strokes with writing instrument strokes using DocuCentre expert (PIA 6000-EDF)

Introduction of the digital techniques in document examination has encouraged the Forensic Document Examiners to work with better accuracy in non-destructive ways. In this study, the examination of sequence of intersecting strokes of printers (inkjet printer, laser printer, dot-matrix printer) and typewriters with writing instruments (gel ink pen, ballpoint pen and fountain pen) of different colors was carried out by using Docucenter Expert via PIA-6000 software utilizing extended depth of focus. The continuity of the stroke is the only characteristic which has been observed at the point of intersection.     

Application of Raman spectroscopy in forensic investigation of questioned documents involving stamp inks

Stamp pad inks from different manufacturers across India have been analyzed to investigate the feasibility of Raman scattering as a tool for forensic analysis of questioned documents involving stamp inks. Nine different stamping inks were analyzed by both Raman spectroscopic and HPTLC methods. The results demonstrate the effectiveness of these methods in classifying the investigated stamping inks based on their spectral pattern and HPTLC chromatogram. Raman scattering tool was able to determine the sequence of heterogeneous intersection strokes involving a blue stamp pad ink and other writing instruments, such as ballpoint pen ink (red and black), pencil and laser printer toner. However, this method was unable to resolve the exact sequencing for the intersection strokes involving investigated stamp ink and blue ballpoint ink or gel pen ink (all colors).     

光谱成像检验法在朱墨时序鉴定中的应用

光敏印文色料与签字笔书写色料交叉重叠后,因互溶渗透不易形成层状结构而使判定朱墨时序的难度较大。光谱成像检验法是通过比较交叉点、纯印文色料、纯墨迹色料处的反射曲线位置来判定交叉时序关系。     

An evaluation of matching unknown writing inks with the United States International Ink Library

Utilizing a database of standards for forensic casework is a valuable resource. Undoubtedly, as more standards (and corresponding information about the specimens) are collected, there is a greater certainty of identification when a questioned and a known item cannot be distinguished after a series of analyses. The United States Secret Service and the Internal Revenue Service National Forensic Laboratory jointly maintain the largest known forensic collection of writing inks in the world, which is comprised of over 8500 ink standards collected worldwide, dating back to the 1920s. This study was conducted to evaluate the reliability of matching arbitrarily purchased pens with known inks from a database. One hundred pens were randomly obtained from a variety of sources and their respective ink compositions were compared with standards. Eighty-five of the inks were determined to be suitable for comparison utilizing optical examinations and thin-layer chromatography. Three of the inks did not match any of the specimens on record; one of these inks was similar to an ink from an identical brand of pen that was in the database, but had a modified formulation.     

A lifting process for determining the writing sequence of two intersecting ball-point pen strokes

The authors describe a technique for determining the order in which two intersecting ball-point pen strokes were made by means of lifting part of the ink with KromeKote paper. The KromeKote paper is applied to the intersection with the glossy side against the writing. The back of the lifting paper is rubbed with a blunt pointed instrument using moderate pressure. Study of the lift under low magnification discloses a pattern of edge markings with those from the last written line dominating the intersection. Results show a high percentage of accuracy.     

Characteristics of erasable ball point pens

In 1979 shortly after the introduction of the erasable ball point pen two papers were published describing its basic characteristics (W.J. Flynn, J. Police Sci. Adm., 7 (1979) 346–349; P. Pfefferli and J. Mathyer, Rev. Int. Criminol. Police Tech., (1979) 407–419). Since that time two additional makes of pens and other colors of ink have been introduced, and the quality of writing has been significantly improved.The ink of the erasable pen differs significantly from that of the standard ball point pen, and for that matter from ink of all other modern day pens. In what way might this newer pen produce a written line different from other ball point pens? This is one question that the paper addresses with limited success.When erased, what techniques can be used to attempt to determine the text of the original writing? The writer considers all standard methods for deciphering erased writing and discusses modification by use of infrared film with oblique light photography — the method most successful in determining the original contents of the erasure.     

签字笔笔痕同一认定充分条件的分析

签字笔因其具有书写流利、使用方便的特点，是现今最常见的书写工具之一。文章根据签字笔的结构特点和笔痕特征的形成机理，结合收集的96份实验样本，首次对签字笔笔痕进行同一认定应具备的充分条件进行初步研究，探讨了书写纸张施胶程度、衬垫物软硬程度、书写人运笔力度以及书写速度等书写条件因素的具体影响，同时研究了签字笔启用初期与末期书写笔痕特征可能出现的变化问题，总结出笔痕特征反映性、稳定性和特定性的具体特点，提出书写条件与书写笔的相近书写阶段均是签字笔笔痕同一认定充分条件的重要组成部分的观点，以期对文检工作者利用笔痕特征有一定的借鉴意义。     

Determining the sequence of intersecting gel pen and laser printed strokes — A comparative study

The relative chronological sequence of intersecting gel pen ink lines and laser printed marks has been determined using optical methods. The results were obtained by observing spectral reflection, relative sheen, skipping and gaps of gel pen ink strokes at the point of intersection. The intersections are observed under stereomicroscope and digital microscope. The effectiveness of both the optical instruments for sequence of the strokes has been compared. The sequence of intersecting lines (of same colour, different colours and where one of the strokes is darker) has been established.     

国产圆珠笔油墨字迹书写时间的鉴别

对国产圆珠笔油墨字迹书写时间的鉴别进行了实验研究,达到了检测速度快,实用性强,费用低的效果.     

多次测定法确定蓝色圆珠笔字迹形成时间

通过研究相隔一定时间的多次测定数据的变化规律与书写时间的内在关系，建立了部分近期书写的圆珠笔字迹形成时间的检验方法，确定了相隔一定时间的两次测定数据的变化规律与书写时间内在关系的判定阀值。形成了无需对照样本即可判定部分圆珠笔字迹是否近期书写的检验方法。     

透析法测定钢笔墨水字迹的书写时间

本文通过最新研发的透析液,根据透析的原理,对书写在不同种类纸张上的不同种类的钢笔墨水字迹进行了书写时间测定。在基本保证透析液的浓度、厚度和钢笔字迹色料浓淡一致的基础上,考查了不同种类钢笔墨水字迹和不同种类纸张对透析结果的影响,得出了一般性规律,并介绍了该项新技术的原理和操作方法。