Ground Penetrating Radar in Forensic Science: Applications, Methodologies, Challenges, and Future Directions, A Comprehensive Review

ABSTRACT: Ground-penetrating radar (GPR) has emerged as one of the most valuable non-invasive technologies in forensic science, enabling subsurface imaging in investigations involving clandestine graves, missing persons recovery, concealed evidence, and mass fatality incidents. The technique transmits short electromagnetic pulses into the ground and records the reflected energy generated by contrasts in dielectric properties between subsurface materials. These reflections allow forensic practitioners to delineate buried anomalies with centimetre-scale accuracy while preserving the integrity of the crime scene. This review documents the evolution of GPR from its earliest forensic applications through to current state-of-the-art systems, focusing on core methodologies, data acquisition and processing protocols, and integrated approaches combining electrical resistivity tomography (ERT), LiDAR, and artificial intelligence. Case studies drawn from diverse settings, including volcanic caves, urban environments, ice-covered water bodies, and tropical forests, demonstrate both the operational versatility of GPR and the contextual limitations that practitioners must recognise. Signal attenuation in high-moisture soils, interpretive ambiguity in heterogeneous environments, and inconsistent operator training remain the principal constraints on GPR performance. These challenges highlight the need for standardised protocols, certified training, and evidence-based deployment criteria. Emerging technologies, including drone-mounted GPR arrays, convolutional neural network-based radargram interpretation, and three-dimensional (3D) subsurface reconstruction, are expected to improve detection precision, reduce field time, and extend operational capability in challenging forensic scenarios. By critically evaluating the published literature and identifying research priorities, this review demonstrates that GPR is not merely a useful adjunct but an increasingly indispensable tool in modern forensic investigations, with the potential to support ethical, time-efficient, and scientifically defensible recovery operations.