Determining an optimal sequence for chemical development of latent prints on cartridge casings and shotgun shells.

In developing latent prints on cartridge casings and shotgun shells, multiple chemical processes should be used in order to obtain the best results. In Phase I, this study established an optimal chemical sequence for both Brass and Nickel cartridge casings based on six sequences involving four chemicals: Cyanoacrylate, Black Powder, Rhodamine 6G and Acidified Hydrogen Peroxide. Phase II was a validation study of Phase I involving a random sample of both Brass and Nickel cartridge casings, which were processed according to the determined optimal sequences. In addition, ribbed shotgun shells were processed under Phase I results and determined to be dependent upon the utilization of a CrimeScope at 515 nm. Consideration should be given to the type of cartridge case being examined. Although limitations exist, some chemical sequences undeniably work better than others. All photographs were manipulated with Adobe Photoshop. All results were verified by a senior latent print examiner.