Forensic Department "Environment-Fire-Explosives"
Forensic Expert - Forensic Department "Environment-Fire-Explosives", IRCGN
Characterizing human odor is of particular interest in forensic science. Dogs can find a person using their odor-print, but cannot testify: the information they bring lacks probative value in the courts of justice. Thus, developing a whole analytical strategy, from sampling to analysis and data processing, may support the identification dogs provide.
First, this communication will focus on techniques for human hand odor sampling. This crucial step was performed either by direct contact, an adsorbent being put directly on the skin of the subject during a predefined time, or indirectly with a home-made device based on air suction. Both direct and indirect samplings were optimized using designs of experiments.
Then, TD-GC×GC-MS methods were developed using a mixture of 80 compounds representative of human hand odor. This technique allowed to perform efficient separations, to get more resolutive chromatograms, and therefore hopefully to collect enough information for further identification. The performance of several sets of columns was compared by considering nine of the criteria most used in the literature. The last step is the implementation of advanced statistical data treatment for odor comparison and determination of target components.
Our first results are promising since different people generated distinct odoriferous profiles. For the approach to be used as a supportive evidence, further statistical data treatment have to be implemented to compare samples and provide identification.
The convergence of both frequentist and Bayesian approaches would bring more weight to evidence in courts of justice.
The first results are promising and the analytical characterization of human odor would allow to support dogs for human identification.
Statistical Treatment, Comprehensive GC, Human Scent