Forensic document examination in handwriting and signature cases can be
complicated by writers with motor disorder conditions such as
Parkinson's disease and essential tremor. These conditions are more
prevalent among the elderly and legal issues arise in probate and elder
abuse fraud cases where parkinsonian patients sign their signatures to
checks, estate, title, and financial documents that are frequently
contested. Because writers with motor disorders produce distorted,
tremulous handwriting, distinguishing between genuine movement disorder
signatures and forgeries can be problematic for handwriting experts. To
address the problem, the author conducts original research using
innovative digital tablet technology that allows for objective,
quantifiable measurement of dynamic handwriting factors such as
duration, velocity, pressure, and frequency spectrum analysis of writing
tremor. The results have implications not only for handwriting experts
working with ink writing and online biometric signatures, but also the
elderly, motor disorder patients, legal professionals, investigators,
law enforcement, and the justice system.