John W. Bond, Scientific Support Unit, Northamptonshire Police, Wootton Hall, Northampton, England and Trudy Loe, Scientific Support Unit, Northamptonshire Police, Wootton Hall, Northampton, England
Abstract: Visualization of differential oxidation on phase brass, subject to heating to temperatures of up to 600°C, is shown to be enhanced by selective digital mapping of colors reflected from the surface of the brass using Adobe® Photoshop®. Enhancement is optimal when the brass is heated to ~250°C with areas of oxidation having a mirror like appearance. The use of this enhancement method to visualize fingerprint sweat deposits on brass cartridge cases is demonstrated.
Digital Mapping of Differential Oxidation Arising from Fingerprint Sweat Deposits on a-Phase Brass