Cani da cadavere: “dispositivo biologico specializzato” nell’individuazione di tracce ematiche latenti sulla scena del crimine. Da mito a prova scientifica.

Aim. The canis lupus familiaris, due to his particular olfactory characteristics, is used by the police to detect a wide range of substances (explosives, gunpowder, narcotics, etc.). Trained dogs to the discovery and reporting human remains or not visible cadaveric blood, can be of great help. This study set out to investigate and validate with scientific method, a training protocol of dogs specialized for research, tracking and reporting of cadaveric latent blood traces of blood. Methods. We used two Labrador Retriever. The study was conducted for sixteen months, with about 200 hours of simulation and 6240 surveys, within a room suitably equipped. We used blood of four patients who died due to trauma, collected in sterile and VOCs free tubes. The first phase of the training focused on the ability of the two dogs to hold the smell target and signal their presence at concentrations always decreasing. In the second phase confounding factors were introduced. Results. The study found the real effectiveness of dogs trained to identify human cadaveric blood in very low concentrations. Tests conducted have shown a good ability to discriminate human cadaveric blood in combination with confounding factors in high concentrations (olfactory accuracy). Conclusion. The use of dogs in this area necessarily requires standardization of training procedures in order to achieve “certified” for this specialized biological device the same rigorous level of reliability and reproducibility required for all methods of investigation in the forensic field, through an optimized and tightly controlled training, through the evaluation of olfactory sensitivity, the ability of olfactory discrimination and olfactory accuracy.