Micro-Raman Study of the Sequence of Non-Intersecting Lines for Forged Document Investigation

In connection with investigation of fraud, counterfeiting, blackmail and anonymous letter cases, forensic experts frequently have to find out whether a document was altered after signing. In these cases the sequence of crossing printer and pen ink line often needs to be determined in order to resolve whether any of the printed text was printed after the signature. When there are no intersecting lines between the printed text and the pen ink lines, standard techniques used for sequencing are not applicable. This note demonstrates the application of micro-Raman spectroscopy to investigate the chronological sequence of printed and hand-written features on the documents even if there are no intersecting lines.