AFTE Store - The Probability of Corresponding Straie in Toolmarks

Two significant and practical corresponding relationships used to compare and determine the common origin of striated toolmarks are the number and quality of corresponding striae. It is essential to know how many striae can correspond by chance in order to determine the discriminating power of these relationships. The probability of chance correspondence (i.e., % match), and the maximum number of conscecutively matched striae was estimated for variation in the density of the striae, the critical coincidence ratio (CCR), and the width of the striaeof the marks compared. The critical coincidence ratio is a measure of how each specific striae compared is counted as corresponding or not corresponding. The results generated by this simulator study will be used to evaluate the discriminating power of these relationships and allow the implementation of effective and efficient automated systems applied to the comparison of real striated toolmarks. Automated comparison systems applied to real striated toolmarks (i.e., fired bullets) will in turn allow comparisons on a scale sufficient to establish and validate objective criteria for the comparison of striated toolmarks to detemine common origin.