Historical and recent challenges to the practice of comparative forensic examination have created a driving force for the formation of objective methods for toolmark identification. In this study, fifty sequentially manufactured chisels were used to create impression toolmarks in lead (500 toolmarks total). An algorithm previously used to statistically separate known matching and nonmatching striated screwdriver marks and quasi-striated plier marks was used to evaluate the chisel marks. Impression toolmarks, a more complex form of toolmark, pose a more difficult test for the algorithm that was originally designed for striated toolmarks. Results show in this instance that the algorithm can separate matching and nonmatching impression marks, providing further validation of the assumption that toolmarks are identifiably unique.
Available at: http://works.bepress.com/l_chumbley/48/
This is a manuscript of an article published as Spotts, Ryan, and L. Scott Chumbley. "Objective analysis of impressed chisel toolmarks." Journal of forensic sciences 60, no. 6 (2015): 1436-1440, doi:10.1111/1556-4029.12863. Posted with permission.