A Further Evaluation of the Electrodeposition of Gun Blue: Part 2-Integration with Subsequent Forensic Analyses

• Published in: Journal of forensic identification Vol. 70; no. 4; pp. 497 - 526
• Main Authors: Dove, Aaron, Hockey, Daniel, Knowles, Laura, Wilkinson, Della
• Format: Journal Article
• Language: English
• Published: Alameda International Association for Identification 01.10.2020
• Subjects: Comparative studies; Criminal investigations; Firearms; Forensic sciences
• ISSN: 0895-173X

Previous studies by Dove have shown that adding an electric charge to the treatment of brass or nickel-plated cartridges by gun blue improves the contrast and quality of the resulting fingermark development when compared to current operational techniques. In order to determine whether the electrodeposition of gun blue is suitable for operational deployment, its impact on subsequent forensic techniques must be assessed. This paper examined the impact of electrodeposition of gun blue, palladium deposition, and passive gun blue deposition on subsequent DNA extraction and analysis using the Promega DNA IQ System and phenol-chloroform extraction techniques. It also examined the impact of the electrodeposition of gun blue on subsequent toolmark examinations. The electrodeposition of gun blue, passive deposition of gun blue, and palladium deposition all negatively impacted the subsequent DNA analysis, to varying degrees. Therefore, alternate DNA analysis techniques would need to be considered. The electrodeposition of gun blue also had a negative impact on some of the weaker toolmarks used in toolmark analysis, indicating that toolmark examination should be performed first.