Polymerisation of S2N2 to (SN)x as a tool for the rapid imaging of fingerprints removed from metal surfaces

Abstract

Polymerisation of S 2 N 2 to (SN) x on metallic surfaces is induced by interaction with the minute corrosion signatures of removed (by washing) fingerprints; as vapour-phase S 2 N 2 is employed, it follows that the process has the potential to rapidly screen large/convoluted metal pieces, such as explosive device fragments whose prints were wiped by the detonation.

A comparative evaluation of the disulfur dinitride process for the visualisation of fingermarks on metal surfaces

“…Promising results have been obtained on brass using this process, and it was also observed that the process continued to visualise marks on surfaces that had been wiped clean [35].…”

“…The equipment used for the S2N2 process in this study was a developmental system assembled from a combination of bespoke and commercial off-the-shelf components. This design incorporated observations on the desirable features of equipment used in previous research [34,35] but on a larger scale. A schematic diagram of the assembly is shown in Figure 2 below.…”

“…S2N2 has been previously shown [35] to be capable of developing marks after samples have been washed with water, and therefore this experiment explored this in comparison to other processes. The same procedure and number of donors as outlined for the ageing experiment above was used.…”

Harnessing volatile luminescent lanthanide complexes to visualise latent fingermarks on nonporous surfaces

“…Recent innovations to address this challenge include adoption of nanoparticle materials, [2] harnessing near-IR emission for highly emissive surfaces, [3] targeting new biological components, [4] and new chemical treatments for challenging surfaces like bullet casings. [5] Vacuum metal deposition (VMD) is a commonly used technique for visualising latent fingermarks owing to its high sensitivity, and applicability to a wide range of surfaces. It works by depositing metal films (e.g.…”

Advances in the development and component recognition of latent fingerprints

“…These include powder dusting, fluorescent dyes, ninhydrin/1,2-diazafluoren 9-ONE staining, cyanoacrylate/iodine fuming, and vacuum metal deposition [13,14]. Synthetic techniques [11,[15][16][17][18], metal [19,20] and semiconductor nanoparticles (NPs) [13,21,22], as well as electrochemical methods [23][24][25], have also been exploited. In addition, the past few years have witnessed a renewal of research interest in the possibility that a fingerprint can provide additional information about the donor than mere identification [7].…”