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Year : 2019  |  Volume : 5  |  Issue : 1  |  Page : 19-23

Lacunae in Forensic Handwriting Examination: Scope for Exploitation

1 Director, Head of Department of Physiology, Maulana Azad Medical College, New Delhi, India
2 Chief Coordinator of Research and Academic Cell, Department of Physiology, Maulana Azad Medical College, New Delhi, India

Date of Web Publication30-Apr-2019

Correspondence Address:
Dr. V. P. Varshney
HOD Office, Department of Physiology, MAMC
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/mamcjms.mamcjms_25_19

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The process of forensic handwriting examination consists of two steps: the first step is the objective phase of the process and requires correct ocular observation to make a note of similarities and dissimilarities in the two samples of writing; the second step is subjective phase and depends on proper evaluation of what is observed based on expert’s belief, assumption and experience. The second phase, because of its subjective nature, can also be exploited by dishonest expert resulting in conflicting evidence. This scenario is obviously disruptive for justice, and generally weakens the credibility of this type of evidence.

Keywords: Forensic science, handwriting comparison, objective analysis, subjective evaluation, evaluation exploitation, conflicting reports, identification

How to cite this article:
Varshney VP, Bedi M. Lacunae in Forensic Handwriting Examination: Scope for Exploitation. MAMC J Med Sci 2019;5:19-23

How to cite this URL:
Varshney VP, Bedi M. Lacunae in Forensic Handwriting Examination: Scope for Exploitation. MAMC J Med Sci [serial online] 2019 [cited 2022 Sep 25];5:19-23. Available from: https://www.mamcjms.in/text.asp?2019/5/1/19/257423

  Introduction Top

Two or more handwriting experts can reach different conclusions on authorship when examining the same questioned documents and handwriting exemplars. When courts are faced with opposing experts, each of whose expert testimony contradicts the other, they tend to disregard entirely the physical evidence upon which the experts are testifying. Since only one of the opinions can be correct, other expert has either erred or exploited the situation for his vested interest.

The earliest handwriting examination cases reported go back to the third century AD. Historical references indicate that the practice of forgery and related frauds involving documents evolved almost as early as the development of writing.[1] Over at least the last 150 years, many published scientific studies have focused on the individuality and reproducibility of handwriting for use in a forensic setting.

The classic work of Osborn “Questioned Documents” laid the scientific principles of handwriting identification and forgery detection. He stated that identification is based on the ‘Law of Mathematical Probabilities’ in accordance with Newcomb formula and recommended measurements which are so vital in scientific studies.[2] He was an advocate of measurements as a means of objective examinations and demonstration of evidence to a jury. Eyeballing a document is non-scientific according to Wilson Harrison’s ‘‘Suspect Documents’’.[3] Forensic document examiners seldom use measurements in their examinations to the extent described by Osborn. According to Morris [4], the science of handwriting examination follows the established scientific principles, some of which are:
  1. No two people write exactly alike, nor do they incorporate in their writing exactly the same combination of characteristics, qualities, and features.
  2. No single writer writes exactly the same way each and every time. Some normal range of variation in writing is expected in everyone’s writing, the extent of which is dependent upon a number of factors, such as his level of graphic maturity, as demonstrated by his relative speed of writing, and a multitude of additional factors.
  3. The significance of any combination of characteristics, qualities, and features as evidence to establish the identity of a writer is directly proportional to the speed, spontaneity, and naturalness with which the writing is written, and inversely proportional to its prevalence rate in the similar text material of other people, and its agreement or disagreement with comparable feature (s).
  4. No one is able to imitate all the features of another person’s handwriting and simultaneously write at the same relative speed and skill level as the writer he is seeking to imitate. This is especially true for the greater relative speed the model writer uses. Further, in simulating another person’s writing, the simulator tries to imitate those features that strike him the most. The simulator either tends to disregard those features that are inconspicuous or fails to imitate them successfully.
  5. For those writings where the writer successfully disguises his normal handwriting habits or where he imitates − traces − the writing habits of another writer while leaving no trace of his own, it is virtually impossible to identify the imitator.

For a meaningful examination and comparison, the two samples of writing, questioned and known, must be suitable and sufficient in quantity and quality along with sufficient individuality.

  Discussion Top

Handwriting identification is a study and comparison of writing attributes and it is based on basic scientific principles known as Law of ACEs i.e. Analysis, Comparison and Evaluation. This three-part process is defined by R. A. Huber and A. M. Headrick [1] as follows:

Analysis or property selection: The discriminating elements of writing attributes are identified from the known and unknown handwriting samples. These elements may be directly observable, measurable, or otherwise perceptible aspects.

Comparison: The discriminating elements of the unknown determined through analysis must now be compared with those known. Comparison is not only for forms but, more importantly, a consideration of the writing movements behind those forms.

Evaluation: Similarities or dissimilarities in properties or characteristics (discriminating elements) will be assigned a value of significance for identification purpose, depending upon their cause, relative speed, naturalness and frequency in general population. Writing is said to be natural when it is executed without concealing the normal writing habits of the writer.[4] In natural writing, the pen is likely to write most if not all letters of a single word without leaving the paper.[5] A primary indicator of unnatural writing is wavering or broken strokes and loss of relative pressure habits between upstrokes and downstrokes, but they are also the natural accompaniment of slow or immature writing and therefore it becomes necessary to rule out the low level of “graphic maturity” before the writing is declared as unnatural.[4]

According to traditional theory, handwriting can be broken down into class characteristics (features which are found in the writing of groups of people) and individualities (features particular to one writer). The writing of all people will have both class characteristics and individualities.[6]

Analysis and ocular comparison are the two objective aspects which are dependent on the visual mechanisms. Both are objective observations made on ocular examination. An objective observation is an object, concept, phenomenon, or condition in the realm of sensible experience independent of individual thought and perceptible by all observers. Scientific method relies heavily on observation (sensory input), reproducibility (observing the same output from the same input repeatedly) and consensus (agreement by others on what is a correct observation). The most logical first step in the objective phase of handwriting comparison is to determine if the questioned writing/signature was naturally made or are there any signs of forgery/simulations/imitations in the questioned material. These signs reveal the fraudulent nature of the questioned material, if they are not present in the known samples.[7] Although very minute differences in discriminating elements may not be observed on ocular examination due to the visual mechanisms e.g., the difference in the size of two objects will not be perceptible if this difference is in microns but it will be observed if it is in mm, cm or meter. Gross differences or clearly noticeable differences in the discriminating elements are perceptible by all, irrespective of whether the person is an expert or a layman. If the expert claims that he cannot appreciate the differences even though they are perceptible by others or he can see the differences which the others can’t see then he is wrong. There are no signs, occult or otherwise, that can only be seen by the expert. The expert does not have magical eyes. The eyes of the document examiner are just like those of a layman. They are not in possession of special powers of vision. The only difference between a layman and an expert is that the latter can appreciate the subtle differences quicker with naked eyes because of his training and experience; a layman would need magnification to appreciate the same differences. Enlarged exhibits are therefore often required to appreciate the detailed, subtle and minute structure of disputed handwriting to reveal evidence that cannot be seen without magnification. The document expert may be better in evaluating the ocular observations made in the course of search. Gross differences can be appreciated by both without magnification. Forensic handwriting comparison is not just an analysis of forms but, more importantly, a consideration of the writing movements behind those forms.[8] So, failure to notice/observe gross or significant defects in forms or characteristics of writing movement should not be accepted as an excuse for the expert on the pretext of human error, because this cannot be expected from him who is supposed to be well trained in his field. This is an act of negligence or wrong doing. Thus, the objective part of forensic handwriting examination requires accurate observations, and therefore mandates to thoroughly scrutinize the material being examined, taking notes of similarities and differences. The expert cannot claim that he could not find any difference as this is not possible even when two pieces of writing by one person are compared. Thus, the expert cannot exploit this part of examination, and if he does so, then it proves his dishonest intention.

On the other hand, the evaluation aspect of forensic handwriting examination is purely a subjective component and depends on proper reasoning of the observations. Many errors occur if the examiner misses, ignores or justifies the differences on account of natural variation (even when they fall outside the range of variations of the known standards), thus underestimating the differences and focusing primarily on the similarities. It is to be remembered that similarities alone do not necessarily prove the identity of the writer and leads to erroneous results if this is the only criterion used to support the findings. Since there is not enough material to establish clearly what a fundamental difference is and what makes a difference significant,[9] the evaluation of the significance of the similarities or differences is not consistent even among the forensic handwriting experts. Thus, this aspect is vulnerable to exploitation in the hands of unethical experts. In the evaluation phase, the unethical expert can assign a value of significance to similarities or dissimilarities according to his whims and fancies. He can identify class characteristics (features common to many people) as individual characteristics (features peculiar to a specific writer introduced as a result of departure from the norm) or vice versa although, the majority of individual characteristics are inconspicuous and have to be diligently sought for, even by those experienced in the critical examination of handwriting. Each person’s writing contains a combination of class and individual characteristics. The extent of these combinations depends upon the individual. This is one of the basic reasons why handwriting is identifiable. The ability to distinguish between class characteristics and individual characteristics is widely believed to be one of the fundamental bases by which a document examiner can make judgments and form opinions to distinguish one person’s writing from another.[10],[11] It has been argued that a document examiner’s unfamiliarity with the class features of a given population can lead to the misidentification of a feature as unusual when it is in fact a common feature. This can lead to an error of judgment that compromises the handwriting examination.[8] Further, without systems and copybook forms, there is no frame of reference to distinguish between class and individual handwriting characteristics occurring as a result of deviation or departure from the norm.

The expert can also justify any difference on the basis of disguise or variations in one person’s writing (natural variation), although there is no established methodology to differentiate a disguised writing from the writing where the writer is different. Various factors such as mechanical, physical health, mental condition, medication, substance abuse and psychological factors may also affect writing causing observable differences. These factors may be given as the explanations for the observed differences in handwriting samples. Also, there is not enough empirical data to assess the significance of a writing feature in terms of its prevalence in writings of other persons so the expert can use his own self-made data depending on his experience and intention. The examiner may acquire a mindset that restricts eliminations to certain specified situations like when the writing skill of the suspect is inferior to that of the questioned writing or some other person has been identified as the writer. Since the explanation of the difference, whether acceptable or unacceptable, is a subjective component, the expert should avoid making positive identification, if the questioned writing is unnatural and does not represent the true samples of the writer. In fact, some commentators suggest that the furthest an examiner can go is to say that the questioned signature (if simulated or disguised) exhibits features that are not natural to the known writer. Also, there is no uniform single definition of the fundamental (significant) difference that can always be for the elimination of a suspect in handwriting case. So, determination of fundamental difference varies among practitioners based on their experience and judgment. Another area which makes ground for exploitation is the quantity of handwriting samples required for comparison. There are no clear guidelines that specify the number of writing samples needed for analysis as the requirements may vary with the writer and the circumstances, as per the literature available. In the absence of a simple answer to the question on how to determine the quantity of exemplars in a particular case for handwriting comparison, exploitation is bound to occur.[1] So, one examiner can cite ‘no conclusion’ opinion in view of insufficient number of standards although that number may be sufficient for another expert. Such limitations (whether claimed to be scientific or non-scientific) or mindset may provide the expert an opportunity to exploit the situation for his vested interests. Thus, the expert opinion (interpretation) is subjective information depending upon his assumption, belief, and experience or reasoning ability and can be separate from the individual’s perception of ocular observations. Conway goes on to say that no handwriting is susceptible to identification, if it is not truly representative of its source (the writer) i.e., it must exhibit the normal and natural writing habits of the writer.[12] To be identifiable, a questioned handwriting must bear significant, stable and unique characteristics upon which to base an opinion. The basis for identifying a questioned handwriting occurs when the writing shows no signs of disguise, tracing or simulation but reveals significant unique characteristics, providing those features are also present in the known writing without any unexplained observable difference. The key hypothesis (character of scientific investigation) − “the writer of these exemplars (set K) is also the writer of this questioned material (set Q)” used in forensic handwriting examination is to be supported by correct measurements and observations. All the writing habits defined by the set of known handwriting must match the writing habits observed in the questioned writing, if this fundamental hypothesis is true and there must not be any unexplained observable difference.[13] The comparison of any two pieces of writing will show that there are differences between them, even when these two pieces of writing are by one person.[5] The differences observed in handwriting comparison must be accounted for before drawing conclusions on its identification. Any explanation for differences must be demonstrable and reasonable for it to be convincing. The critical element in the evaluation phase is in determining what constitutes a reasonable explanation for the observed difference. The erroneous conclusions are made when there is failure to give proper weight to the differences. Although, the evaluation aspect can be exploited by an expert with dishonest intent on the pretext of subjectivity, the clearly perceptible differences that can be appreciated by all cannot be ignored by the expert on this pretext. The perceptible difference observed on ocular comparison of handwriting is objective information.

There are ‘21’ aspects or attributes (discriminating elements) of writing which are studied in handwriting examination.[1] There are seven elements of style. These seven elements are arrangement, connections, construction, design, dimensions, slant or slope, spacings, class and choice of allographs. The difference in any element of style is known as Disparity and it is significant. Disparities emanate from different teachings, different backgrounds, and different practices. They are more often attributable to a difference in writers. Then, there are 10 elements of execution, and the difference in one of its discriminating elements of execution is called divergence. It is often the product of variation in the same writer that may either be a natural variation or variation due to some special cause. Two elements i.e. natural variation and persistency are attributes of all writing habits and the remaining two i.e. lateral expansion and word proportions are due to combinations of writing habits.

The following are the requirements for concluding that two or more writings are of common authorship if they are a) naturally written, have b) sufficient and significant individuality, are in c) complete agreement, and have d) no significant observable differences other than those resulting from normal variation, then it can safely be concluded that the writings are of common authorship.[4] Individuality is described as handwriting features and characteristics that are departure (s) from a norm. As the writer matures, he departs from the use of some of the class characteristics (writing habits / attributes common to a large group of people) he learned and introduced into his writing thus imparting it individuality. The significance of a discriminating element as evidence of identity or non-identity depends upon its frequency of occurrence within random writings (the significance varies inversely to its frequency of occurrence in similar text material in the writing of different persons), the relative speed and naturalness with which it is written, and its agreement or disagreement with comparable feature (it must fit within the writer’s range of variation). It is the combination the class and individual handwriting characteristics that makes handwriting identifiable.

Similarities, while playing a role in the process of examination and comparison of writings, are not as significant or as fundamental as significant differences are in handwriting comparison. Many people share common handwriting characteristics and even some distinctive handwriting characteristics. In examining a disputed document, the true test is not the extent of the similarities with genuine documents as forged documents are good imitations of genuine documents but the nature and extent of the dissimilarities noticed as the differences expose the true character of the documents in question (Ravjappa Vs Nilakanta Rao AIR 1962 Mysore 53). The weight must be given to differences which cannot be accounted for by natural variation of a single writer. The importance of unexplainable difference is evident in the following well-known rule applicable in handwriting comparison—“that whatever features two specimens of handwriting may have in common, they cannot be considered to be of common authorship, if they display but a single consistent dissimilarity in any feature which is FUNDAMENTAL to the structure of the handwriting, and whose presence is not capable of reasonable explanation”.[3] Thus, the unexplainable dissimilarities between a person’s natural writing and questioned handwriting will preclude a positive identification.

For most document examiners a question of signature authenticity is the central issue in more than 90 percent of their cases. Fundamentally, the identification principles set forth for general handwriting and signature are the same, but certain factors require greater emphasis. A signature is a combination of a rather limited number of letters or symbols. Because of its frequent use, it becomes with almost all individuals automatic habitual handwriting. Most people have stylized their signatures into a form that is comfortable for them and easily executed.[14] The skill of execution and the movement of the pen can be ascertained from a careful study of the signature itself. Almost without exception, all non-authentic signatures contain flaws in both execution and design. A non-genuine signature can generally be detected because of the inherent defects in how it is written (i.e., line quality). Line quality assessment is the backbone of forensic signature examination. Line quality is defined as the visible record of the written stroke.[15] It represents the basic fundamental element of movement producing the form.[16] The various parameters or characteristics i.e. elements of movement which are considered while examining/assessing the line quality are speed, pen pressure and its variation, line continuity, pen stops, pen lifts, hesitations, rhythm, freedom, uniformity of writing, degree of smoothness, added or extra stroke if any, skill (The line quality reveals skill level of the writer) etc. The difference in line quality is a fundamental difference (any irreconcilable difference) and indicates a different writer.[7] One of the biggest sources of error is the failure to fully investigate the line quality. In signature examination three factors are to be considered: form, line quality (movement), and variation.[17] Poor line quality is the most frequently encountered inherent defect in simulated signatures/handwriting. The forger must write more slowly in order to imitate the writing style being copied resulting in drawn appearance of the written strokes i.e. there is even pressure between the upstrokes and down strokes unlike the normal writing which is characterized by pressure variation between the upstrokes and down strokes. An increase in writing speed typically results in relative pressure habits i.e. the down strokes are heavier than upstrokes.[4] In simulation, more accuracy is achieved when the pen travels for a shorter distance resulting breaks in the written line. While simulating the model signature if the forger succeeds in imitating the speed, the form of the signature will suffer.[7]

  Conclusion Top

The exploitation of the subjective phase of handwriting examination can be avoided by listing the similarities and differences (between the questioned and known documents) and providing scientific and demonstrable causes or basis of the differences. The handwriting expert must also place on record the enlarged exhibits to make clear their point. The expert should provide an explanation for those differences only where he can demonstrate and prove the reasoning scientifically. The expert should not make an unreasonable or non-scientific statement in explaining the difference. It should be left to the court to decide which cause or logic is more convincing to explain the occurrence of any difference in the two samples depending upon the facts and circumstances of each case. The scientific information so provided will enable the court to form its independent judgment by the application of these criteria to the facts proved by the evidence of the case. This will minimize the professional hazards associated with forensic science of handwriting identification and will help the court in understanding its importance and administering justice.

To conclude, handwriting examination by forensic experts is an extremely complex job. It, therefore, requires complete attention to each minor detail to make correct ocular observation during the objective analysis along with a complete understanding of the basic principles of handwriting identification so that the writing characteristics are properly evaluated.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Huber RA, Headrick AM. Handwriting identification: Facts and fundamentals. Boca Raton, LA: CRC Press 1999.  Back to cited text no. 1
Osborn A. Questioned documents. 2nd ed. Chicago, IL: Nelson-Hall 1929.  Back to cited text no. 2
Harrison W. Suspect documents. Chicago, IL: Nelson-Hall 1981.  Back to cited text no. 3
Morris RN. Forensic handwriting identification: Fundamental concepts and principles. San Diego, CA: Academic Press 2000.  Back to cited text no. 4
Ellen D. Scientific examination of documents: Methods and techniques. 3rd ed. Boca Raton, FL: CRC Press, Taylor & Francis 2006.  Back to cited text no. 5
Levinson J. Questioned documents: A lawyer’s handbook. London: Academic Press 2001.  Back to cited text no. 6
Koppenhaver KM. CDE, forensic document examination: Principles and practice. Totowa, NJ: Humana Press 2007.  Back to cited text no. 7
Hilton O. Scientific examination of questioned documents. Chicago, IL: Callaghan & Company; 1956.  Back to cited text no. 8
McAlexander TV. Assigning weight to handwriting differences for elimination purposes. Int J Forensic Doc Exam 1997;3:4-7.  Back to cited text no. 9
Simner ML. The origin of class characteristics: An empirical investigation of a major principle in forensic document examination. J Forensic Doc Exam 1998;11:39-50.  Back to cited text no. 10
Found B, Rodgers D. A consideration of the theoretical basis of forensic handwriting examination. Int J Forensic Doc Exam 1998;4:109-18.  Back to cited text no. 11
Conway J. Evidential documents. Springfield, IL: Charles C. Thomas 1959.  Back to cited text no. 12
Slyter SA. Forensic signature examination. Springfield, IL: Charles C. Thomas 1995.  Back to cited text no. 13
Koppenhaver KM. Attorney’s guide to document examination. Westport, CT: Quorum Books; 2002.  Back to cited text no. 14
Kelly JS, Lindblom BS. Scientific examination of questioned documents. 2nd ed. Boca Raton, FL: CRC Press 2006.  Back to cited text no. 15
Hilton O. Line quality—Historic and contemporary views. J Forensic Sci 1987;32:118-20.  Back to cited text no. 16
Hilton O. Signatures—Review and a new view. J Forensic Sci 1992;37:125-9.  Back to cited text no. 17


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