Biasability and reliability of expert forensic document examiners

The relative ability of forensic document examiners (FDEs) to provide support for the proposition of individualization or exclusion on the basis of handwriting features was investigated by surveying opinions expressed in case files by one laboratory’s FDEs and comparing this data to blind trial test results taken over a five year period. The survey of FDEs opinions on reports showed that opinions were skewed towards support for writer individualization over writer exclusion 92% of the time. Since historically FDEs develop their skills with respect to individualization/exclusion primarily on case files, it is proposed that this unbalanced training context may skew their abilities to carry out the tasks. To determine one laboratory’s capacity to correctly provide both individualization and exclusion evidence, results of blind validation trials were analyzed. For natural writing written and not written by the specimen writer, FDEs were 62 times more inconclusive when providing support for exclusion of the specimen writer when the specimen writer did not author the questioned sample, than they were for providing support for individualization when the specimen writer wrote the questioned sample. An intriguing possibility is that because of the unbalanced training set, government FDEs may acquire skills which are skewed towards individualization over exclusion. Purchase Article - $10

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The Frequency of Occurrence of Handwriting Performance Features Used to Predict Whether Questioned Signatures are Simulated

Journal of Forensic Document Examination ◽

10.31974/jfde28-35-42 ◽

2018 ◽

Vol 28 ◽

pp. 35-42

Author(s):

David Black ◽

Bryan Found ◽

Doug Rogers

Keyword(s):

Large Population ◽

Quality Parameters ◽

Frequency Of Occurrence ◽

Relative Speed ◽

Simulation Process ◽

Spatial Features ◽

And Performance ◽

Document Examiners ◽

Line Trace

Forensic Document Examiners (FDEs) examine the physical morphology and performance attributes of a line trace when comparing questioned to specimen handwriting samples for the purpose of determining authorship. Along with spatial features, the elements of execution of the handwriting are thought to provide information as to whether or not a questioned sample is the product of a disguise or simulation process. Line features such as tremor, pen-lifts, blunt beginning and terminating strokes, indicators of relative speed, splicing and touch ups, are subjectively assessed and used in comparisons by FDEs and can contribute to the formation of an opinion as to the validity of a questioned sample of handwriting or signatures. In spite of the routine use of features such as these, there is little information available regarding the relative frequency of occurrence of these features in populations of disguised and simulated samples when compared to a large population of a single individual’s signature. This study describes a survey of the occurrence of these features in 46 disguised signatures, 620 simulated signatures (produced by 31 different amateur forgers) and 177 genuine signatures. It was found that the presence of splices and touch-ups were particularly good predictors of the simulation process and that all line quality parameters were potentially useful contributors in the determination of the authenticity of questioned signatures. Purchase Article - $10

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Effect of Visual Feedback on the Static and Kinematic Characteristics of Handwriting

Journal of Forensic Document Examination ◽

10.31974/jfde27-5-21 ◽

2017 ◽

Vol 27 ◽

pp. 5-21 ◽

Cited By ~ 1

Author(s):

Michael Pertsinakis

Keyword(s):

Visual Feedback ◽

Educational Level ◽

Movement Analysis ◽

Individual Characteristics ◽

Software Module ◽

Medium Education ◽

Education Levels ◽

Pen Tablet ◽

The Individual ◽

Document Examiners

Research on visual feedback has not produced consistent results to show how visual feedback or the lack, thereof, influences individual handwriting characteristics. A two-pronged approach was designed to investigate the degree of this influence. For this purpose, samples of signatures as well as cursive and block text, written with and without visual feedback, were collected from 40 volunteers and imported into a PC via a pen tablet, using an electronic inking pen. The data was analyzed in a handwriting movement analysis software module specially designed for this research that was added to the software MovAlyzeR by Neuroscript LLC. Two forensic document examiners (FDEs) independently analyzed samples from the two groups (samples executed with normal visual feedback versus the group of samples executed without visual feedback). They found no fundamental differences between these two groups. Their analyses also demonstrated that a large number of similarities existed in the general design of the allographs (alternative forms of a letter or other grapheme) and in the pictorial aspects, regardless of the complexity of the samples. In the cursive and block handwriting, four main qualitative characteristics were linked to the absence of visual feedback: change of overall size, non-uniformity of left margins, change of baseline alignment, and inclusion of extra trajectories. The statistical analysis verified the above findings. The comparative analysis also suggests that gender, educational level (above high school) and handedness create an insignificant influence on the individual characteristics of writing produced with and without visual feedback. The only notable exception is the relationship between signature duration and educational level. The volunteers with a medium education level showed a significant increase in duration while signing their names without visual feedback in comparison to those with higher education levels. The combination of the above findings suggests that handwriting is not fundamentally influenced by visual feedback. Purchase Article - $10

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Multiform Korean handwriting authentication by forensic document examiners

Forensic Science International ◽

10.1016/j.forsciint.2015.07.002 ◽

2015 ◽

Vol 255 ◽

pp. 133-136

Author(s):

Tae-Yi Kang ◽

Joong Lee

Keyword(s):

Document Examiners

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A Handwriting Compendium for Document Examiners

Handwriting Identification ◽

10.1201/9781420048773.ch2 ◽

1999 ◽

Keyword(s):

Document Examiners

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The Sources of Document Examiners

Handwriting Identification ◽

10.1201/9781420048773.ch13 ◽

1999 ◽

Keyword(s):

Document Examiners

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A study of the effect of substrate on dot-matrix printing

Nowa Kodyfikacja Prawa Karnego ◽

10.19195/2084-5065.44.2 ◽

2017 ◽

Vol 44 ◽

pp. 9-21

Author(s):

Komal Saini ◽

Varinder Singh ◽

Manpreet Kaur ◽

Seema Sharda

Keyword(s):

Absorption Spectra ◽

Background Noise ◽

Physical Characteristics ◽

Uv Fluorescence ◽

Different Types ◽

Multiple Documents ◽

Document Examiners

A study related to Dot-matrix printers has been carried out in order to analyze the effect of change of substrate on its printing characteristics. Twenty Dot-matrix printers and five types of substrates or white pages have been selected for the study. The printouts have been taken on all the five types of white papers from each of the twenty Dot-matrix printers. These printouts have been examined using stereomicroscope 4x40magnification and VSC 2000 C to examine the features such as change in colour of ink, lustre of printing text, impact of printing, spreading of ink, background noise, UV fluorescence and absorption spectra. It has been concluded that the physical characteristics of dot-matrix printing gets changed by changing the type of substrate even in case of the same printer. Thus, the results of this study would definitely help the forensic document examiners to give an accurate opinion on the cases related to Dot-matrix printouts, specifically in the examination of multiple documents consisting of different types of papers.

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