Fingermark development on living and dead subjects: analysis of thermal paper transfers with different methods

Fingermarks used in forensic investigation are biometric elements widely utilized in identification thanks to their unique and classifiable characteristics. Despite numerous studies investigating fingermark development on different surfaces, few studies have addressed the skin surface of deceased individuals, given the challenging nature of this substrate. This study investigated the transfer and development of fingermarks on human skin that had been systematically deposited over the forehead, neck, and wrist. Additionally, gender, age, and the time elapsed since deposition were issued as additional factors impacting fingermark development. Therefore, we prepared a study setting representing a crime scene by modelling the scene and then utilized 400 fingermarks. The marks transferred to thermal paper were developed by applying ThermaNin and magnetic black fingermark powder as fingermark development methods and then photographed. They were then evaluated for their suitability for identification via scoring and statistical analysis. The results indicated that 36% of all marks obtained from the skin of living persons and 66% of those from skin surfaces of dead bodies received the highest score and were assessed as suitable for identification. Despite the negative effect of increased time since deposition, it was revealed that the ThermaNin method yielded better results than magnetic black fingermark powder.