Indented Writing Examination: Rubber Stamp Image Transfers

Electrostatic Detection Devices, used by Forensic Document Examiners, are well known for their ability to recover indentations from documents. The impressions are usually the result of the pressure generated from pen strokes written upon a document placed over another document. However, images are occasionally captured that were not simply the result of pen pressure, but other types of paper fiber disturbances. This paper is related to an uncommon type of non-impact indented writing evidence recovered during casework. An image of a rubber stamp impression was recovered from the page positioned on top of the document during shipping. The vivid image was surprising, because it was not a concentrated pressure impression common to pen stroke indentations, nor due to indentations from one page affecting the following page through friction. The research conducted in this paper duplicatedthe results.
Several rubber stamp impressions, using various stamps and inks, were made on individual pages. The pages were then placed over a blank page, using various paper types. The file was mailed across the country, then returned. The blank pages were processed, and several stamps became clearly discernable. The transfers were subsequently determined to be caused by the inks’ chemical components. The results further established that images obtained from an Electrostatic Detection Device (EDD) are not restricted to common paper fiber disturbances associated with signatures or other handwriting. The rubber stamp image may also be transferred to a page preceding, as well as following, the originating document.