A proof-of-concept study into turmeric spice as an improvised fluorescent latent fingermark detection powder for limited resource jurisdictions

Abstract

Latent fingermarks are a crucial form of physical evidence for crime scene investigations; however, limited-resource jurisdictions, such as some states in Brazil, face challenges in identifying fingermarks due to lower access to commercial fingermark developers. The study of unconventional and alternative techniques for fingermark detection that are low-cost, easily available, and sustainable in line with the UN SDGs presents great value for under-resourced jurisdictions. Household items and easily available materials such as spices fit perfectly in such contexts as improvised fingermark powders. Turmeric is a globally accessible culinary spice which contains high levels of the fluorescent compound curcumin. This research reports for the first time the application of turmeric spice powder as fluorescent dusting powder for latent fingermark detection. Turmeric spice powders from different sources were evaluated for their performance as dusting powders and were subsequently characterised by optical microscopy, Fourier transform infrared spectroscopy, and fluorescence spectrophotometry. All turmeric powders exhibited high fluorescence intensities and were demonstrated to be suitable as fluorescent fingermark powders without further processing, though specimens with homogeneous particle size distribution and pure turmeric composition performed better. These preliminary results indicate that turmeric is a suitable fingermark powder without further modification and is a potential alternative to commercial powders for jurisdictions with limited resources.