The detection of latent residue tattoo ink pigments in skin using invisible radiation photography

The identification of tattoos often provides important forensic information when investigating criminal activity. Tattoos may be used by police intelligence as a source of identification of known criminals. Tattoos may be effaced by laser surgery so that they can no longer been seen by visual inspection of the skin. However, remnants of pigment persist within the dermis. This paper describes a novel technique using infrared photography that can demonstrate the presence of tattoos that have been ablated by lasers. The method provides adequate detail of the tattoo's characteristics to aid in forensic identification. A literature search did not reveal any known methods of detecting latent residue inks after removal or detecting alteration of a pre-existing tattoo.