In fact, there are many conditions of water that can contact with the fingerprint containing material surfaces, such as water from rain, roadside, effluent, canal or sea. The water from each source is quite different in its pH, salt types and levels and suspended particulate matter. However, the effect of the pH or salt concentration of the soaking solution upon the ability of each SPR to detect latent fingerprints has never been investigated. In this study, various types of surface samples soaked in each different solution (tap water, weak acid, weak base, and various concentrations of sodium chloride), which represents water from some of the different available sources, was used to evaluate the effect on latent fingerprint detection by SPR.