Yang Chiew Yung, Lim Chin Chin and Tan Yan Wen, Crystal
73rd Annual Meeting of the American Society of Questioned Document Examiners,
Toronto, Canada, Aug 8-13 2015. (poster presentation)
In alleged “cut-n-paste” tampering cases, it could be crucial to determine if a signature and stamp impression on a questioned document could have been reproduced from an undisputed “reference” document. The original questioned document is usually unavailable, and photocopies or scanned copies of both the questioned and reference document are submitted instead. The examination of signatures is more straightforward as it is an accepted principle of forensic handwriting identification that no one person writes exactly the same way twice, and no two signatures by the same person would resemble each other so closely because of the presence of natural variation in handwriting. The examination of stamp impressions on copies may be more problematic, especially if the reproduction quality is poor, and distinguishing defects or trash marks may not be visible from copies. The orientation of the stamp impression may be a useful feature in determining if it could have been taken from an otherwise legitimate document, particularly if the stamp involved is circular with no obvious “upright/correct” position. What is the significance of the orientation of a stamp impression? What is the likelihood of obtaining a stamp impression with a similar orientation? This study attempts to provide some answers.