A novel approach to identify the presence of fingerprints on wet surfaces

In forensic science, one of the major problems is trying to reveal the presence of fingerprints on wet surfaces. Not often are fingerprints left in protect environments, so we have to detect their presence on the most different surfaces, after they underwent to the action of atmospheric agents or have been found, for example, on objects floating in the water. Small Particle Reagents (SPR) is a technique performed to detect latent fingerprints left on wet or moist surfaces based upon the reaction between the fatty-acid residuals present in the traces and hydrophobic tails of the specific reagents. Those tails are linked to a hydrophilic head reacting with a titanium dioxide salt giving a white precipitate plainly detectable. In this report, we want to show that exalting fingerprints left on plastic, glass and metal wet surfaces is possible with the SPR technique independently on the time fingerprints were in contact with water, as we performed in our experimental procedure. Results in details.