4.1. Case report
In this section we show how we employed our method in a real casework. A highway ticket was treated with spray ninhydrin (SIRCHIE 201c) and, for this reason, the thermal surface of the
paper was black and it was not possible to reveal any fingermark on it. We performed the inspection in the NIR region by exploiting the VSC6000 (excitation wavelength 410–640 nm, examination wavelength > 695 nm) and this technique allowed us to reveal fingermarks
otherwise not visible, and to identify the owner of the latent prints. As shown in Fig. 10, when viewed in the visible region, it is impossible to suppose that there could be fingermarks on the
paper. This casework gave us the input to realize the study presented in this paper.