Concentric fractures in the skull are produced differently in blunt force and ballistics trauma. Since bone breaks on the tension side first, concentric fractures will fracture first on the outer table in blunt force trauma and on the inner table in ballistics trauma. This should produce internally beveled concentric fractures in blunt force trauma and externally beveled fractures in ballistics trauma. As used in this study, "beveling" refers to the angle between the outer and inner tables on the fracture surface. The research sample consisted of 79 blunt force and 84 ballistics trauma injuries to 120 skulls that exhibited concentric fractures. Only wounds that displayed concentric fractures were included in the research. Contingency tables and Pearson's Chi-Square were used to assess the relationship between the mechanism of trauma and the direction of beveling, and Pearson's r correlation was used to determine the strength of the relationship. The total sample contingency table showed a direct relationship between the beveling direction and the mechanisms of trauma; 73 of 79 cases of blunt force trauma were internally beveled, and 74 of 84 cases of ballistic trauma were externally beveled. Pearson's r correlation indicated that the relationship between the variables studied was greater than chance allocation, thus supporting the hypothesis that blunt force and ballistics trauma can be differentiated by the pattern of beveling in concentric fractures. 13 figures, 1 table, and 29 references