The silver physical developer currently used in the development of latent prints on porous surfaces is a reagent borrowed from photographic chemistry. It consists of an aqueous solution of silver nitrate, a ferrous/ferric redox couple that contains citric acid, and a cationic and nonionic surfactant. The current silver physical developer is made by using distilled water according to the published procedure. The new formulation described in this paper uses reverse osmosis/deionized (RO/DI) water from an Elga unit. The new formulation of the silver physical developer involves two major changes; it uses RO/DI water and contains malic acid. It also uses less silver, detergents, ferrous salt, and citric acid. The three types of paper that were used in all tests with the new formulation were blue photocopy paper, loose-leaf paper, and brown office envelope paper. For each comparison experiment, five samples were processed for each type of paper. Several experiments were conducted to determine how well the silver physical developer performed when a particular parameter of its current formulation was changed. The effects of the age of the reagent and the latent print were considered. The authors advise that although the new formulation may be better and cheaper than the currently used formulation, it is by no means optimized. There are several questions that remain to be answered in future studies. These questions are presented in the paper. 7 figures, 8 references, and appended detailed description of the new formulation of the silver physical developer