Enhanced Visualization of Latent Fingermarks on Rough Aluminum Surfaces Using Sequential Au and Zn/ZnS/ZnO Depositions1. Issue 4 (3rd November 2017)

• Record Type: Journal Article
• Authors: Tiwari, Anjani Kumar; Alaoui, Ismail Mekkaoui; Guddala, Sriram; Ramakrishna, S. Anantha
• Is Part Of: Journal of forensic sciences. Volume 63:Issue 4(2018)
• Page Start: 1275
• Page End: 1281
• Publication Date: 2017-11-03
• Subjects: forensic science -- latent fingermarks -- rough reflecting surface -- vacuum metal deposition -- reflectance -- enhanced visualization; Medical jurisprudence -- Periodicals; Forensic sciences -- Periodicals; Forensic Medicine -- Periodicals; Gerechtelijke geneeskunde; Gerechtelijke chemie; Gerechtelijke psychiatrie; 363.2505
• DOI: 10.1111/1556-4029.13686
• Languages: English
• ISSNs: 0022-1198

Abstract

Abstract: Detection and visualization of fingermarks on rough and diffuse surfaces is a relatively challenging task. We succeeded in developing latent fingermarks on scratched and rough aluminum surfaces by sequential deposition of a thin layer of gold followed by one of zinc or zinc‐based compounds on the fingermarks. The best image enhancement was achieved with sequential Au and ZnS depositions. Using this combination, we could enhance the visualization of latent fingermarks aged over 65 days in normal conditions. The optical reflectance from the fingermarks with the deposited layers of metal/dielectric is analyzed as a stratified medium. Significant contrast in the reflectance from the regions of the ridges and the valleys of the fingermark would enhance the visualization. Our results show that the Au and ZnS bi‐layer combination can have a large reflection contrast and improved fingermark visualization at wavelengths corresponding to the green light for specific thickness of ZnS.