Behind Armor Blunt Trauma: Recreation of Field Cases for the Assessment of Backface Signature Testing

A total of 47 real-world cases were re-created in a laboratory environment. Cases were identified from the IACP/Dupont® and Safariland survivors' databases. Exemplar armor was obtained for testing in the laboratory. Details surrounding the incident were determined and the ammunition and stand off distance were matched. The armor was placed on the standard preconditioned roma plastilina clay block and struck in the same location as reported in the case study. Both depth of deformation and volume of crater were recorded. Based on the analysis, the average depth of deformation for those cases involving minimal soft tissue damage (i.e., bruising) was 29.2 ± 12.4 mm. The average depth of deformation for those cases involving more severe injuries was statistically greater at 43.6 ± 27.3 mm (p<0.05). The data indicate a 50% risk of severe injury with a deformation of 43.6 mm. (95% CI [33.9 mm, 5.3 m]).