Evaluation of Multimetal Deposition II

• NCJ Number: 201263
• Journal: Journal of Forensic Identification Volume: 53 Issue: 4 Dated: July/August 2003 Pages: 444-488
• Author(s): Naomi Jones; Chris Lennard; Milutin Stoilovic; Claude Roux
• Date Published: July 2003
• Length: 45 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

This article reports on the outcome of research that compared the use of a new formulation of multimetal deposition (MMDII) and vacuum metal deposition (VMD) with standard techniques for latent fingerprint development.

Abstract

MMD has not been routinely applied in latent print development because of its complexity and inconsistent results. MMD is a two-step development process. The first step involves immersing the exhibit in a solution of colloidal gold. The colloidal gold binds to the amino acids, peptides, and proteins within the latent print residue. The resulting development is generally of very poor contrast; therefore, amplification of the print is required. The second step results in selective silver deposition onto the colloidal gold particles, producing a dark gray to black print. A surfactant stabilized physical developer (PD) is used to achieve this contrast enhancement. A new formulation known as MMDII uses smaller colloidal gold particles (14 nm compared to 30 nm) and an alternative physical developer (silver acetate/hydroquinone rather than silver nitrate/iron(II)/iron(III)). Several MMD formulations were evaluated in the current study, and MMDII proved to be the superior formulation, yielding better overall print detail. The VMD unit used in the research was designed and manufactured specifically for latent fingerprint development by Dynavac. MMDII and VMD were compared to standard techniques on a number of semiporous surfaces, including expanded polystyrene, polymer banknotes, waxed paper, latex gloves, and nitrile gloves. The study concluded that on nonporous surfaces, MMDII may offer further print development than that achieved with cyanoacrylate fuming and luminescent staining, but VMD always yielded superior results to MMD; however, on the semiporous surfaces tested in this research, MMDII proved to be the technique of choice. The ability of MMDII to react with print residue within and on the surface is believed to be the key to its effectiveness with these materials. 3 tables, 15 figures, 14 references, and appended details on preparations and procedures used in the research