Exploring micro-CT as a novel approach for postmortem fingerprint identification

Traditional postmortem fingerprinting is often unreliable in cases of decomposition or thermal trauma. Although friction ridge patterns are typically recorded from the epidermis, their anatomical origin in the dermis may preserve identifiable structures, such as friction ridges and sweat pores, even when the skin’s outer layer is compromised. Minimally destructive postmortem imaging techniques capable of visualizing these subsurface structures could therefore greatly enhance forensic identification. This pilot study explores the feasibility of micro-computed tomography (micro-CT) as a novel, minimally destructive technique for visualizing subsurface fingerprint structures in challenging postmortem forensic contexts. Thirteen human finger samples in various postmortem conditions (fresh, decomposed and burned) were included. Four were scanned using micro-CT. Contrast staining was selectively applied. Micro-CT findings were descriptively contextualized using conventional postmortem fingerprinting techniques. Micro-CT imaging successfully visualized friction ridges and sweat gland structures in fresh samples, including at lower scanning resolutions. In decomposed samples, micro-CT imaging revealed little anatomical detail, whereas warm water rehydration restored usable ridge patterns. In burned samples, micro-CT imaging failed to recover ridge detail but visualized sweat gland structures. Micro-CT imaging shows potential as a complementary tool for postmortem identification in burned or fresh remains but provides limited additional value in cases of advanced decomposition. As a pilot study, these findings primarily provide anatomical and technical insights. Future studies should explore larger sample sizes, sweat gland tracing and integration with 3D matching software.