Development of latent prints exposed to destructive crime scene conditions using wet powder suspensions

Fingerprints are the most affirmative source of personnel identification and are also one of the most ubiquitous evidences found at the crime scenes. However, successful latent print recovery is not always possible from the crime scenes especially when the prints have been exposed to destructive conditions. Crime scenes are often despoiled due to destructive conditions such as arson, explosion, exposure to drainage water and soil or snow burial. Moreover, the offender often intends to destroy the fingerprint bearing crucial evidence, using these destructive forces. Furthermore, the fingerprints exposed to despoiled crime scenes are generally neglected due to the misconception of impossible recovery. In the present study, zinc carbonate, zinc oxide and titanium dioxide based fluorescent small particle reagents were formulated, compared and evaluated for the development of latent prints exposed to destructive conditions. Fresh latent prints and prints exposed to natural or simulated destructive crime scene conditions, namely, arson, explosion, burial in soil, immersion in drainage water and burial in snow were developed using the three compositions. Latent prints were successfully recovered even from the destructive crime scene simulations. Better quality prints were obtained from fresh prints, arson, soil burial and drainage water. Relatively poor results were obtained from explosion and snow burial conditions. Wet powder based suspensions were found suitable for development of fingerprints exposed to destructive conditions and the efficiency of the reagents was found in the order: TiO2>ZnCO3>ZnO