In this document, forensic document examiner, Mark Songer, provides an introduction to the science of forensic handwriting analysis. He discusses the steps that a forensic document examiner follows, including analysis, comparison, and evaluation. He also provides a brief example, comparing two handwriting samples, drawing attention to some of the key differences that a handwriting analyst may utilize in his analysis.
The Science of Handwriting Analysis
The science of handwriting analysis is based on the premise that no two individuals can produce exactly the same writing and that an individual cannot exactly reproduce his own handwriting, otherwise known as variation. Variations are natural deviations that occur in a person’s handwriting.
The Process Handwriting analysis involves a comprehensive comparative analysis between a questioned document and known handwriting of a suspected writer. Specific habits, characteristics, and individualities of both the questioned document and the known specimen are examined for similarities and differences.
- Analysis - The first step is to analyze the known writing sample and the unknown writing sample for distinctive characteristics. The examiner looks for unique qualities such as letters and word spacing, letter and word slant, size and proportionality of letters, unusual formations of letters, flourishes, and other individual attributes.
- Comparison - The next step is to differentiate elements from the known sample to those of the unknown sample. The examiner considers spelling, grammar, punctuation, and phraseology as well.
- Evaluation - The final step is to evaluate the similarities in the known and unknown samples. While differences are a good indication of a non-match, no single similar characteristic, no matter how unique, can determine a match. Therefore, all likenesses must be considered. The examiner must make a judgment in each case by evaluating the totality of the documents.
Example
The handwriting examples below are from two different writers. Structural differences (1) can be seen from the letter formations by each writer. Connecting strokes to letters (2) and slant (3) are visible and differ from each writer’s distinctive style. In addition, baseline alignment (4) is considerably unique whereas one writer consistently writes on the baseline and the other repeatedly deviates below the baseline.
In the example: 1) Structural Difference 2) Connecting Strokes 3) Slant 4) Baseline Alignment
Standards
The American Society for Testing and Materials, International (ASTM) publishes standards for the many methods and procedures used by Forensic Document Examiners. E30.02 is the ASTM subcommittee for questioned documents. ASTM E444-09 provides guidance on the scope of work conducted by document examiners, and E2388 specifies minimum training requirements.
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Mark Songer
Forensic Document ExaminerMark Songer is a court qualified expert in Forensic Document Examinations. He provides investigations, reports, and testimony towards the resolution of matters involving disputed documents or… read more.
Forensic handwriting analysis is a pattern-based science that examines significant, repeated handwriting characteristics (i.e. handwriting habits) in questioned writing comparing and evaluating these characteristics in the known writing. Should significant similarities be observed with no differences, this may lead to a handwriting identification.
Forensic Handwriting Analysis
Forensic handwriting analysis is the comparison of two similar types of writing to determine authorship. The goal of forensic handwriting analysis is to analyze, compare and evaluate the handwriting characteristics to determine if the handwriting was or was not prepared by the known writer.
The Science Behind Forensic Handwriting and Signature Analysis
Handwriting is created by an individual using muscular coordination, natural ability, and the mental component of what that individual is trying to write. Handwriting habits of an individual becomes
Principle of uniqueness
Handwriting is a conscious act but the repeated act of writing each word and letter becomes almost automatic. The writer concentrates more on what they are trying to say than on the writing process itself. It is at this time that handwriting demonstrates numerous habitual subconscious patterns. It is these repeated patterns that makes handwriting individual and unique.
Natural Variation
Handwriting is a dynamic process made up of the mental image of what you are trying to say, and the neuro muscular coordination of the writer to imitate the copybook form learned at school with their own individual habits. Because we are not robots, handwriting does not look exactly alike from one writer. Thus, natural variation is part of the handwriting process and serves to make handwriting unique. It is these habits and variations in a person’s writing that can assist to make handwriting identifiabel.
Writing Skill
Handwriting skill is practiced when we first learn to write. As students, we follow a copybook style of writing that our teacher’s demonstrated in the classroom. As each individual is unique, handwriting relies on the mental image of what we are trying to writer, combined with the neuro-mucular act of the writing act itself. These three things combine to make handwriting unique. Handwriting is formative while at school and gradually, a writer reaches a point of graphic maturity where handwriting habits are fixed and change very little. Skill level can improve a little bit with practice however, a writer who has reached graphic maturity cannot demonstrably improve their writing skill overnight. H2 How to analyze handwriting and signature?
How to analyse handwriting
Handwriting analysis involves three key stages including the analysis, comparison, and evaluation of the handwriting characteristics.
Step 1: Analysis
First, determine if the examination is comparing a questioned document to a known document or questioned writing to questioned writing.
Second, determine if the questioned writing is original writing. If not, request the original or evaluate the quality of the copy. Are significant details of the writing
Third, determine if the questioned writing is distorted or natural writing. Evaluate the questioned writing for the type of writing (if there is more than one type, separate the questioned writing into groups) and determine if the questioned writing demonstrates an internal consistency (could there be more than one writer)?
Next, determine the range of variation and the presence or absence of individual characteristics. Proceed with these same steps when examining the known writing.
Key features to be examined:
- Letter formations – how is the letter constructed, how many strokes, one continusous stroke of many strokes combined to make the letter.
- Line quality – the dynamic process which guides the writing instrument across the paper and encompasses many elements such as pen pressure, speed, pen lifts, consistency of the written line, rhythm, and writing skill.
- Alignment – alignment refers to the real or imaginary baseline upon which the writer places the writing.
- Arrangement of the writing – With extended writing, the arrangement of the writing including margins, spacing, address placement, crowding or insertions may be as individual as the writing itself.
Step 2: Comparison
Conduct a side-by-side comparison of the comparable portions of the bodies of writing. Determine if there are differences, absent characteristics, and similarities. Add paragraph
Step 3: Evaluation
Evaluate the significance of the handwriting characteristics individually and in combination. Determine if there is a sufficient quantity of writing. If there is not a sufficient amount of questioned writing, known writing, or both; request more writing and repeat the above steps to the extent possible.
Verification:
After the examination and conclusion are reached, the conclusion is verified by a senior examiner. This includes a technical and administrative review.
Conclusions Reached After Handwriting and Signature Analysis/ Examinations
Standards have been developed regarding the conclusion levels which can be reached by forensic document examiners. These opinion levels compose a nine level scale.
Identification
This is a definite conclusion of identity and the highest degree of confidence expressed by document examiners in handwriting comparison. The examiner has no reservations whatever, and although prohibited from using the word “Fact” the examiner is certain based on evidence contained in the handwriting, that the writer of the known material actually wrote the writing in question.
Strong Probability
The evidence is very persuasive, yet some critical feature or quality is missing so that an identification is not in order, however, the examiner is virtually certain that the questioned and known writings were written by the same individual.
Probable
The evidence contained in the handwriting points rather strongly toward the questioned and known writings have been written by the same individual; however, it falls short of the “virtually certain” degree of confidence.
Indications (evidence to suggest)
A body of writing has few features which are of significance for handwriting comparison purposes, but those features are in agreement with another body of writing.
No Conclusion (totally inconclusive, indeterminable)
This is the zero point of the confidence scale. It is used when there are significantly limiting factors, such as disguise in the questioned and/or known writing or a lack of comparable writing, and the examiner does not have even a leaning one way or another.
Indications Did Not
This carries the same weight as the indications term that is, it is a very weak opinion.
Probably Did Not
The evidence points rather strongly against the questioned and known writings having been written by the same individual, but, as in the probable range above, the evidence is not quite up to the “virtually certain”range.
Strong Probably Did Not
This carries the same weight as strong probability on the identification side of the scale; that is, the examiner is virtually certain that the questioned and known writings were not written by the same individual.
Elimination
This, like the definite conclusion of identity, is the highest degree of confidence expressed by the document examiner in handwriting comparisons. By using this expression the examiner denotes no doubt in his opinion that the questioned and known writings were not written by the same individual.