Forged Signatures Expert Overview

Disputes over forged signatures play a prominent role in a broad range of legal disputes. Common questioned documents include business contracts, wills, checks, deeds, medical records, and a variety of other agreements. This article reviews the signature authentication process by examining a hypothetical signature example. 

Forged Signature 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/her own handwriting due to writing variation. Variations are natural deviations that occur in a person’s handwriting.

Forensic document examiners practice the science of forensic handwriting analysis by following a series of steps: analysis, comparison, evaluation, and verification.

Included is an example comparing two signatures, drawing attention to some of the key characteristics that a handwriting analyst should assess in their analysis.

The Science of Handwriting Analysis

The science of handwriting analysis is based on three basic premises:

1. No two individuals share the exact same combination of handwriting characteristics
2. No person writes the exact same way twice (natural variation), and
3. That an individual cannot write above their demonstrated skill level

Variations are minute deviations that occur in a person’s natural handwriting.

The Process

Handwriting analysis involves a comprehensive comparative analysis between a questioned body of writing or signature(s) with a known body of writing or signature(s) or sometimes between two bodies of questioned writing to determine common authorship.

Specific habits, characteristics, and individualities in both the questioned and known writings are examined for both similarities and differences.

Step One: Analysis 

The first step is to analyze the unknown writing  to determine if it is suitable for comparison and then the same process is followed for the known writing. The examiner is also determining limiting factors if they exist.

Step Two: Comparison

The next step is to compare each and every detail of the questioned to the known bodies of writing.

The examiner considers all aspects of the writing to include letter and word spacing, slant, size and proportionality of letters, formations of letters, line quality, flourishes, attention to baseline and other individual attributes.

Step Three: Evaluation

The third stage is the formulation of a conclusion based on the significance and combination of the characteristics observed during the comparison process along with any limitations presented.

Step Four: Verification

The final stage of the examination process is verification. At this stage, another qualified document examiner reviews the results of the initial examiner using the same methodology described above.  

This process is performed to ensure the following:

• That appropriate examinations of the questioned documents have been conducted.
• The examiner’s conclusions are accurate and consistent with the assigned scope of work.
• The examiner’s conclusions are accurate and consistent within the limits and standards of the discipline.
• There is supporting data to support the examiner’s findings.

Forensic Handwriting Analysis Example

The signatures below have been constructed for demonstration purposes only. The signatures in blue are in question and the signatures in black are part of the submitted known exemplars. In an actual case, the document examiner would have numerous known signatures to assess natural variation.

The top two signatures (in black) are genuine and the bottom two (in blue) are traced from the top two so they ”overlay” in many areas.

An experienced document expert will notice poor, shaky line quality which reveals the signatures may have been simulated or traced. Some writers have shaky writing naturally due to health issues, age or otherwise, but a properly trained expert will be able to assess if this is a natural feature of the known writer or not through the evaluation of the known writing submitted for comparison.

Hesitation marks and pen lifts are present in this example, which are common features in simulated or traced signatures. The red markings highlight some of the aspects observed.

Relevant Standards

Document Examiners rely on a number of standards and guidelines that have been published by the National Institute of Science and Technology (NIST), Organization of Scientific Area (OSAC) Sub-Committee in Forensic Document Examinations as well as the Scientific Working Group for Forensic Document Examination (SWGDOC).

Questioned Document Examinations

Questioned document examination is a discipline within forensic science that pertains to documents with disputed authenticity or origin. A questioned document investigation is used to ascertain the authenticity (or lack thereof) of a document when it comes into question. The examination of known to questioned documents provides analytical results regarding the similarities or differences between the samples using a variety of scientific principles and methods.

To discuss your case with an expert, call us at 800.813.6736 or submit an inquiry.

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