The Efficacy of Acidified Hydrogen Peroxide on Cartridge Cases as a Latent Print Development Technique
Files
Date
2020
Authors
Flores, Camille
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Friction ridge impressions, commonly known as fingerprints, are a type of evidence investigators search for when examining crime scenes and evidence. They are left behind by friction ridge skin after physical contact with a surface. These impressions not readily visible by the naked eye are latent prints. Latent prints are composed of oils, perspiration, and other constituents (Dutelle, 2014). In order to visualize these impressions, agencies follow protocols proven to develop prints on various surfaces of substrates. A cartridge case is a nonporous surface, which means the fingerprint residue will not be absorbed by the substrate. Due to the small surface area and the influence of the firing process on any impression left behind, recovering latent prints on cartridge cases is a challenge. This study aims to analyze the effectiveness of various formulations of Acidified Hydrogen Peroxide (AHP) as a fingerprint processing technique on various metal-types of unfired and fired cartridge cases. A subsequent study analyzes how the processing technique can be implemented in conjunction with three commonly used chemical processing techniques for cartridge cases. The techniques are cyanoacrylate ester fuming, fluorescent dye staining, and gun bluing. This study revealed that a manufactured formula of AHP developed the greatest number of samples compared to other formulae. This study also showed that the sequence of AHP, cyanoacrylate ester fuming, and then R.A.Y. developed the greatest number of samples with measurable ridges by the end of the sequence.