Padronização de metodologia para a identificação de perfil genético de impressões papilares impregnadas com reveladores químicos empregados na Perícia Criminal Militar

Abstract

Fingerprints are the most inveterate vestiges present in the history of mankind. Records dates from 7000 years BC in the Neolithic period and one of the first fingerprints recorded as a form of identification - albeit rudimentary - dates back approximately 1955 BC to ancient Babylon. The need to differentiate individuals in both the civil and criminal spheres has spurred the creation of a fingerprint-based identification system. However, in terms of fingerprints at a crime scene, it must be noted that these are the most fragile traces found and are subject to a wide range of contaminants from the site itself or to a macroscopic disturbance of their morphology, leading to a loss of minutiae precluding identification through dactyloscopy. Therefore, considering the casuistry of the criminalistic in general, the use of this type of biological vestige in another forensic science field is timely. This work aimed to evaluate the possibility of obtaining a genetic profile from fingerprints collected on glass, metal and paper supports and enhanced with some of the commonly fingerprint enhancers used in the Military Criminal Expertise (black magnetic powder, black volcanic powder and cyanoacrylate). Samples were analyzed by real-time PCR using the InnoQuant^® kit (InnoGenomics Technologies, LLC) and therefore analysis of STR regions by capillary electrophoresis using the AmpFlSTR^® MiniFiler kit on ABI Prism^® 3500 Genetic Analyzer (Life Technologies Corporation^©) were conducted. Morphological analyzes were performed using Phase-Contrast Microscopy technique and nuclear staining with DAPI and visualization with fluorescence microscopy aiming a fingerprint analyzes from at the cellular level. It was possible to obtain a genetic profile from most of the tested samples, and the statistical test applied (Kruskal-Wallis) indicated a significant difference between the evaluated groups (p < 0.05). The paper surface has proved to be the least susceptible to the recovery of genetic profiles. The cyanoacrylate developer was the most suitable for the development of fingerprints when it was intended to analyze these traces genetically.