Different Techniques to Determine Fake Signatures

In private practice, most document cases for handwriting experts involve performing handwriting comparisons. Hand writing can be differentiated between two or more people by using certain analytical techniques that are commonly used by handwriting experts.  In the beginning stages, writers have to  learn to write by emulating a handwriting system that is most commonly taught in school during their basic education levels.  As students mature, they quickly stray from the copybook forms to making letters with individualizing features of their own, suiting their own speed and pacing.  These characteristics may include variations in the form of the writing slant such as italics, the spacing between two or more different/same letters, the design and length of approach and termination strokes, the positioning of ‘i-dots’ and ‘t-crossings’, height relationships, the design of numerals, and so forth. 

Naturally, there is natural variation in the signatures and writing styles of all people.  A document examiner will ask for several known writing samples of a suspected writer in order to perform a better comparisons between samples and learn for these variations. By having several specimens, the signature expert is able to establish consistent pattern of the writer.

Handwriting comparisons is a not a simple process.  For example, some signatures may appear to the be the writing of the same person.  However, a comparison by a document examiner may prove a signature in question a ‘cut and paste’ fabrication. 

Signature  forgeries are the most common type of issue clients present to the signature expect they hire.  Many of the involved signatures are abbreviated such as several alphabets are omitted in order to add speed to the signature and lack a few or many of  the individual letters in the name.  It is common for people signing their name frequently to simplify their signature. However, reducing the complexity of a signature increases the ability for someone to simulate it.  That is why it is recommended to have a complex, fluently written signature because it minimizes the chance for a successful ‘forgery’ of the name.

The Forensic Document Examiner (handwriting expert) can also examine documents to determine the method of production of the document. Was the document produced by a typewriter, dot matrix, ink jet or laser printer? Does the document have a signature on it which appears original but is in fact a color laser copy of the signature and not the original inked signature? Does the ink jet printer have a defect that can identify the specific printer used to create the document?

The most common process used for a signature forgery is a free-hand simulation.  The writer simply uses a true signature of the person as a model, placed near the signature line where the forger will copy the genuine signature as well as they can.  If the forger lacks the writing skill and the ability to move the hand in such a way to make a passable forgery, he/she may opt for a “cut and paste” fabrication.  That type of signature forgery is simply the transfer of a genuine signature from one document to another using a software program such as PhotoShop or Paint.