Deciphering Obliterated Signatures using IR Imaging and Reverse Illumination Technique

Obliteration of signatures in questioned documents poses a significant challenge to forensic document examiners, especially when layered with multiple interfering substances such as scribbled pen strokes and correction fluid. This study underscore the efficacy of ultraviolet (UV) and infrared (IR) imaging, using the Docucenter Nirvis system integrated with PIA 7000 software, in deciphering obliterated signatures. Two illumination approaches, front-side and reverse-side were employed. While front-side illumination failed to reveal the obscured content, reverse-side illumination combined with appropriate IR filtering and digital processing enabled successful retrieval of the original signature. The results underscore the importance of reverse illumination as a viable and essential technique in the forensic examination of tampered documents.