Comparing Handwriting

When examining a document, how does the examiner know if a given piece is "authentic" or not? It's a question that's quite important when it comes to forensic investigation, most specifically when it comes to forgery. In truth there are a few broad categories of things that an examiner will...well...examine when looking to determine a document's authenticity as far as signatures and handwriting goes.

Standards
Firstly, when determining the authenticity of the handwriting on a document, samples of the person's handwriting are necessary. These samples are referred to as "Standards" and are the cornerstone of the science of handwriting comparison. The examiner in question uses these Standards as a template to determine whether the document in question is authentic or not.

While examining a document and comparing it to the Standards available there are four types of things that an examiner will look for.

Overall Form
Firstly the examiner will inspect the overall form used in the Standards for differences in the shape of letters and spacing of sentences. How letters begin an end, how they slant and what the strokes of the pen/cil look like at beginning and end are all tell-tale signs that an examiner can search for. People often have very distinct writing styles, and will there-fore have certain tells or quirks within their writing that are easy to look for.

Line Features
When an examiner looks at the features of the lines in a given document they are are looking for hesitation marks, for where a stroke seems unsure as if unused to making it. They are looking for distinctive tremors that are made by the original and authentic writer and attempting to find where the Standards and the questioned document differ significantly.

Margins and Format
Examiners also examine how lines of text are written, whether straight or slanting down. They examine the margins and format of a document and how a writer sticks to or differentiates from standard patterns. This can also give clues as to a documents authenticity.

Content
The final thing that an examiner will take a look at when comparing a document to a Standard is the contents of that document. Looking for phrases, and the grammatical structures used in the Standards to discern the authenticity of the document in question. This is useful for identifying key phrases that a person might repeat often between pieces.