THE EFFECT OF WATER SATURATION AND SUBSEQUENT DRYING ON ESDA EFFICIENCY ON PAPER DOCUMENTS

Abstract

This experiment examined the effect of water saturation on paper documents on the effectiveness of ESDA images after the documents were dried. There were four sample groups (Groups A-D) which were subjected to one, two or three sprays of water or were completely submerged in water for 20 seconds. These methods were chosen to simulate the effect of rain on a document on a possible outdoor crime scene. ESDA images were taken for each document before and after treatment for comparison. A clarity scale was used determine the clarity of the ESDA images obtained in this experiment. It was determined that the greater the water saturation of the document before drying, the less clear the ESDA image obtained became. With respect to water-soaked documents, a new ESDA toner application technique was used to produce an image, hence proving it is possible to recover an ESDA image from water-soaked documents.