Investigation of influence of illumination in a latent fingerprint acquisition system based on a smartphone
Maryah Elisa Morastoni Haertel, André Luiz de Melo, Eduardo José Linhares, Armando Albertazzi · 2018
Fingerprint identification is one of the richest tools available for the forensic examiner in a crime investigation, mainly because of its intrinsic characteristics of unicity and immutability. Among the various types of fingerprint found in crime scenes, latent fingerprints (that requires chemical and physical processes for their revelation) are the most used, given it’s high incidence in crime scenes and the existence of databases and automated computational systems for processing. However, the methods and techniques currently used as standards for revealing and collecting these latent vestiges ends up in the destruction of the original evidence, also requiring specific skills and materials, which has high cost and difficulty of access to many Forensic Institutes, like the Brazilian IGP. In addition, there is a negative influence of the physical (moisture) and chemical (organic and inorganic substances) characteristics of the surfaces during the revelation of latent fingerprints. In the current research, a prototype adaptable to a smartphone was developed, using a special light configuration to emphasizes the latent fingerprints. The system was able to obtain latent fingerprints on smooth surfaces in a practical, accessible and non-destructible way. However, the need for specific hardware equipped with other light options for different surfaces was observed. Results shows influence of different wavelengths and the positioning of the illumination on indoor and outdoor environments. As the research advances, we expect the system to become more solid, with the outcome of results more adequate to criminal investigation.