Questioned Documents Analysis for Decipherment of Obliterated Writing

Obliteration with the application of erasure is made with intent to cheat someone. Documents are changed in numerous ways, and every method requires separate technique for detection and decipherment of the original writing. It is very challenging task for document examiners, hence new detection methods should be developed to detect obliterated writing written with similar ink, which cannot be detected by the conventional method. In the present study 20 different types of documents were collected and then reconstructed samples were prepared for the study. Out of which 10 samples were prepared by using physical erasure and 10 samples were prepared using chemical erasures on different types of Papers. For the document reconstruction purpose we use 16 different types of writing materials with four erasures. In this research we investigate the use of Multispectral imaging on Visual Spectral Comparator (VSC-6000 HS, Foster and Freeman Co Ltd England) for decipherment of writing with similar ink. The experimental results demonstrate that obliterated writing with same color ink, which cannot be detected by the conventional method, can be detected by Multispectral imaging.