Looking at the Ink Distribution for Assessing Writing Modalities in Forensic Handwriting Examination

We present the motivations and the results of an investigation aimed at establishing to which extent bumps observed in the ink trace do not correspond necessarily to hesitation of the writing movements but can be observed in fluent handwriting as well. We will show by experiments that this latter case occurs very often and provide an explanation in term of the characteristics of the neuromuscular system involved in writing. Those observations provide also the ground for the features of the ink that discriminate between fluent and hesitant writing movements. We eventually discuss the implications on the practice of forensic handwriting examination.