A New DFO Method for Developing Latent Fingermarks on Thermal Paper
Journal of Forensic Investigation · 2014
A new method for improvement of DFO-treated latent fingermarks on thermal paper will be described in this paper.A DFO powder suspension was prepared using an ultrasonic cleaner to ensure DFO's maximum solubility.The new method in this paper effectively developed latent fingermarks on a variety of thermal paper substrates and provided more friction ridge details and even better contrast without ink running, damage to documents, or background coloration.Examination and photography should be conducted in the luminescence mode, with excitation at 532 nm and observation with orange-red goggles.In addition, some tests were performed, leading to an optimized working solution and the sensitivity, selectivity and stability of the method were also investigated.