DETERMINATION OF SEQUENCE OF WRITING IMPRESSIONS AND BALL PEN INKSTROKES USING THE ESDA TECHNIQUE

The determination of the sequence of ball pen inkstrokes and writing i mpressions on paper has a number of important forensic applications. A study was undertaken in the form of two blind trials involving 150 sa mples of impressions over inkstrokes and inkstrokes over impressions. By using the ESDA technique, in many instances it was possible to dete rmine, from the appearance of the intersection of writing and impressi on, when an impression ran over an inkstroke, with no ''false positive s'' being recorded. In the case of writing over impressions, the seque nces were correctly identified although a small percentage of ''false negatives'' were also recorded.