Natural Signature
Questions often arise regarding handwriting and signatures in particular referring to whether the questioned signature is genuine or non-genuine. One of the first things to observe is to determine if the signature is naturally written. A signature that is naturally written will display tapered beginning and ending strokes, a variation in writing pressure (i.e. relative pressure habits) and the rhythm of the writing will be well-executed.
Other evidence indicating naturalness is the relative speed of the writing by the light upstrokes and heavy downstrokes, the smoothness of strokes, and good line quality.
Original Signatures
If reviewing an original document, it should be examined microscopically to determine whether there is a “wet – ink signature” and evidence to support an actual ink line or if there is evidence of a reproduction.
Ball Point Pen Characteristics
Under magnification, a ball point pen may exhibit characteristics helping differentiate it from other writing instruments. The ink is fast drying and the quality of the writing line is determined by the width and quality of the writing strokes. Defects may be present including gooping (small deposits of ink especially at points of redirection), skipping, and striations within the strokes.
Printing Characteristics
An inkjet printed signature, for example, will show multi-colored dots in cyan, magenta, yellow and black. Various printing processes use different technology to get the images on the paper and this is reflected by what you may see under a microscope. It’s best to hire an expert to make the determination regarding an original ink signature versus a non-original signature.
Writing inks can be differentiated amongst the numerous variety of pens and inks that have been invented. Analytical methods have been developed by ink chemists and good results may be obtained. For example, an ink examination may indicate that a questioned ink is consistent with that found in the suspect pen or if there is a pen having an ink of the same formula.
Non-destructive Ink Testing
Non-destructive testing is often the first step by a forensic document examiner to determine between two pen classes or ink formulas. Testing may begin by microscopic examination and the use of infrared and ultraviolet light sources along with dichroic filters to help distinguish changes exhibited by the ink.
Destructive Ink Testing
More exacting methods include thin layer chromatography (TLC), gas chromatography/mass spectroscopy (GCMS), Fourier transform infrared spectrometry, and Raman spectroscopy. These types of examination need the consent of the submitter of the evidence because these methods are destructive and should only be used as a last resort. Should a non-destructive or destructive ink examination be requested, Meredith Miller can perform the work in-house for non-destructive testing or help you find a reputable chemistry laboratory for destructive testing, as required.
