Investigations on stainless steel knives using fingermark development processes including Recover Latent Fingerprint...

The disulfur dinitride (S₂N₂) process has demonstrated an ability to develop fingermarks on a range of metal substrates. However, the commercialised system 'Recover Latent Fingerprint Technology (LFT)', which utilises this scientific process, has not been evaluated on stainless steel kitchen knives, an item commonly encountered in major crime cases in the United Kingdom. This paper reports on the planted fingermark experiments conducted to investigate the Recover LFT performance relative to, and after, other visualisation processes; such as Superglue Fuming (with and without Basic Yellow 40 dye staining), Carbon-based Powder Suspension, Basic Violet 3 and Acid Violet 17. The results from this study indicate that Recover LFT is a promising process for fingermark visualisation on the blades of stainless steel kitchen knives. Additional studies are required in order to fully assess and determine the benefits of the process and to optimise the position in a sequential processing chart. This novel process would also benefit from a deeper understanding of the underlying chemistry.