AFTE Store - Preservation and Examination of Tool Marks on Cartilage and Bone

The purpose of this research is to find the best method for preserving and examining tool mark characteristics on cartilage and bone. A paper cutter and axe were selected as tools. Cartilage from pig ribs was selected as the medium for imparting paper cutter marks while shoulder blades and hip bones from cows were selected as the media for imparting axe marks. Ten combinations of preservation agents and storage conditions were selected for testing. Casts of all tool marked surfaces, made before preservation, were used as a baseline for comparison. The casts of tool marks, made after preservation were microscopically examined, compared to casts made before preservation, and scored to evaluate the performance of the preservation agents in their respective storage condition. Results indicated that most aqueous solutions stored in a cold environment performed well in preserving the finer accidental characteristics. The best solution and method, however, is to submerge tool marked tissue samples in a 0.9% NaCl saline solution, store them in a frozen state and, when removed from storage, air dry them thoroughly before casting with COE-FLEX or a similar impression material for identification work.