Impact evidence and post-ricochet behaviour of shotgun pellets ricocheting off standard floor tiles

Abstract

Compared to popular handguns and rifle bullets, quantitative and empirical-based ricochet studies using shotgun pellet ricochets are observed to be far fewer. This empirical study examines the ricochet behaviour and impact evidence when shotgun pellets (Buckshot) ricochet off standard floor tiles, providing a series of novel findings related to the resultant ricochet marks. Among these findings, a novel and statistically significant relationship between the lengths and widths of individual ricochet marks and the shot impact angles is demonstrated, offering useful forensic application. Ricochet mark shapes and morphologies highlighted in this study at different impact angles demonstrate the interactions between the ricocheting spherical pellets and tile surfaces, and the effects of acting frictional forces and degree of energy transfer in the production of impact evidence on the tile surface. Relationships with high statistical significance were also reported between the shot spreads on the tile surfaces and the post-ricochet cardboard witness screens, with shot impact angles. Finally, this work reports on the first documented observations of ’Pinch Points’ and ’Nucleus’ ricochet marks with shotgun pellet ricochets as angle-specific phenomena.