Forensic Document Examiners (FDEs) use traditional optical and measurement tools to assist in their work. Now, motor control science studies have developed new tools that can bring an entirely new dimension to the knowledge base of the FDE. These tools can assist FDEs to better analyze information about individualizing movements made by the hand/arm of the writer when producing the writing. Currently, FDEs look at the static writing and form opinions about the dynamic process of the writing such as movement, rhythm, fluency and speed. The FDE never sees the questioned handwriting being produced.
The technology that is helping both scientists in motor control and FDEs is in the form of the Wacom™ graphics tablet, combined with the Movalyzer® software application from Neuroscript™
. The Wacom™ Tablet
and software are powerful tools that allow FDEs to study in real time, the relationship of the dynamic movement to the resulting writing.
The Wacom™ Tablet is a computer input device that is used by artists as a "paintbrush" to create art on the computer screen, and is used by motor control scientists to capture the movement parameters of the pen/stylus. The tablet is available in different sizes and with varying capabilities. Included with the tablet is a non-inking pen/stylus which contains a sensor that communicates through the tablet with software in the computer. The graphic artist can set colors, line widths, and other artistic variables within a software program such as Adobe Photoshop so that movements of the pen on the tablet create "paintings" on the computer screen. Similarly, motor control scientists (or FDEs) can set options in the Movalyzer® software so that 100 or more readings per second are captured, detailing the position and pressure vectors of the pen. Software calculations yield data about the speed and acceleration of the pen. The sensitivity of the pen, tablet and software are such that "airstrokes" written 1/4-1/2 inch above the tablet are also captured and made visible on the monitor.