Diffuse Reflectance FTIR of Latent Fingerprints and Discriminant Analysis for Sex Identification in Humans

Latent fingerprint is an important crime scene evidence, but it is not always recoverable or technically suitable for analysis with fingerprint patterns. Forensic science has shown that other information can be explored from traces using chemical compounds. Infrared spectroscopy is a nondestructive technique that is widely applied to a variety of forensic evidence. In this work, infrared spectroscopy and partial least square discriminant analysis were used to determine the human sex based on latent fingermark analysis. Fingerprint samples were taken from 42 male and female donors, then kept in either dark or light storage conditions, and the Fourier transform infrared (FTIR) spectra were measured considering a period of up to 30 days from collection. The regions from 3000 to 2800 cm^-1 and 1790 to 1150 cm^-1 presented the greatest differences in the peak intensities among the two sex groups. The results showed a correct discrimination rate higher than 80%.

Keywords:
sex determination; latent fingerprints; fingermarks; chemometric analysis; FTIR