Development of latent fingermarks on surfaces submerged in water: Optimization studies for phase transfer catalyst (PTC) based reagents

• Latent finger marks on non porous surfaces as well as on adhesive tapes have been submerged in water up to 100 hours.
• The same could be visualized successfully with the application of Phase Transfer Catalyst based reagent.
• The results obtained were compared with the other routine methods like Cyanoacrylate, SPR etc.
• Proposed method has been found to be more effective and reproducibility than other technique.

The use of a phase transfer catalyst (PTC) based reagent for the development of latent fingermarks is relatively a recent one and therefore a thorough evaluation is required before making any suggestion for its use in the routine fingermark development protocol. In the present study, non-porous surfaces including the sticky side of adhesive tapes loaded with latent fingermarks (eccrine, groomed and natural fingermarks) were submerged in water for different times and were treated with a PTC based reagent to develop fingermarks. The PTC based reagent was able to develop latent fingermarks on various surfaces submerged in water for different time intervals. The proposed method has been compared with standard methods like superglue fuming, small particle reagent and gentian violet (for adhesive tapes). The results have shown that the duration of submersion and the method selected for visualization have influences on the quality of developed fingermarks. The performance of the PTC technique against conventional methods was evaluated and compared thoroughly as a part of the optimization studies for the reagent.