ISSN: 0022-1198
Published Online: 1 March 1998
Page Count: 5

Use of Acidified Hydrogen Peroxide to Remove Excess Gun Blue from Gun Blue-Treated Cartridge Cases and to Develop Latent Prints on Untreated Cartridge Cases
Cantu, AA
Research coordinator, fingerprint specialist, and chemist, U.S. Secret Service (USSS), Forensic Services Division, DC

Leben, DA
Research coordinator, fingerprint specialist, and chemist, U.S. Secret Service (USSS), Forensic Services Division, DC

Simms, JR
Firearms and toolmarks examiner and latent print examiner supervisor, Maryland State Police, MD

Kopera, J
Firearms and toolmarks examiner and latent print examiner supervisor, Maryland State Police, MD

Ramotowski, R
Research coordinator, fingerprint specialist, and chemist, U.S. Secret Service (USSS), Forensic Services Division, DC

(Received 7 May 1997; accepted 18 August 1997)

Abstract

A formula used by firearms and toolmark examiners to clean lead residue from bullets was also found to remove excess gun blue coating from metal cartridge cases. It consists of a mixture of acetic acid and hydrogen peroxide and works by oxidizing the coating back into solution. This explanation allows one to determine the optimum proportion of the mixture. Acidified hydrogen peroxide formulas were also found to “clean” (oxidize or etch) metal cartridge cases in areas where there was no sebaceous latent print material (or other substances that resist oxidation). The subsequent treatment of these “cleaned” cartridge cases with gun blue to enhance the latent print contrast was also considered.

Keywords:
forensic science, gun blue, latent fingerprint, acidified hydrogen peroxide, cartridge cases, metal etching, metal deposition, oxidation-reduction

Paper ID: JFS16135J
DOI: 10.1520/JFS16135J
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