Abstract: This paper describes the sequence of analyses used to determine the nature of a stain located on the floor of room in the former Athens Mental Health and Retardation Hospital in Athens, OH. The location of the stain was reported to be the position in which a decomposing body was discovered on January 11, 1979. The current stain is found to contain strong evidence for both natural decomposition products and deliberate adulteration. Microscopic analyses, solubility tests, FTIR, ICP-OES, pyrolysis-MS, and derivatization GC-MS were consistent in determining the removable parts of the stain to be composed mostly of calcium and sodium salts of free fatty acids, such as palmitic acid, consistent with previous descriptions of adipocere. The free fatty acids could have been formed via known bacterial degradation pathways or via saponification through the basic environment caused through contact with the concrete. To our knowledge, adipocere formation on an exposed indoor environment has not been described before. The stain and concrete also show signs of being chemically modified with an acidic reagent, such as Blu-Lite—a phosphoric acid-based cleaner that was a commonly used cleaner in the building from the time of discovery to the present day. The chemical etching appears to have been restricted to an area resembling the shape of a human body, which is consistent with deliberate adulteration of the appearance of the stain.