Eight unembalmed postmortem human specimens (four males and four females) were used to determine the energy per unit area required to penetrate various regions of the body with less-lethal 12-gauge, fin-stabilized, rubber rocket rounds.
A universal receiver with 12-gauge barrel attachment was used to fire the projectile from a distance of 1.5 m. A chronograph, placed 0.55 m from the specimen, was used to determine the exact terminal velocity of the projectile upon firing. Following each impact at a given location on the body, a visual inspection of the injury was performed. The wound was labeled penetrating or nonpenetrating, and further assessment of the injury was performed after testing was completed. Penetrating wounds were defined as the disruption of the skin and underlying tissue. Slight tearing, discoloration, or marking of the skin without damage to underlying tissue was considered a nonpenetrating wound. A total of 166 impacts were performed, with at least 10 impacts conducted for each region identified. The average energy density required for penetration varied by body region. The region with the lowest average energy density for all penetrating impacts was the area between two ribs with a value of 33.14J/cm2. The posterior rib had the highest average energy density of 55.90J/cm2 for all penetrating impacts. The large differences between the anterior and posterior rib locations are likely due to the comparative muscle and contours of the rib in the respective areas. In addition, the average skin thickness of the anterior skin overlying the ribs varied. Although study limitations are noted, the current study fills a research gap by determining the likelihood of penetration for a higher number of impact areas tested and higher impact velocities than previously reported. Individual models should be developed and used for each specific region. 4 tables, 7 figures, and 8 references