Knife and Saw Toolmark Analysis in Bone: A Manual Designed for the Examination of Criminal Mutilation and Dismemberment

• NCJ Number: 232864
• Author(s): Steven A. Symes Ph.D.; Erin N. Chapman M.S.; Christopher W. Rainwater M.S.; Luis L. Cabo M.S.; Susan M.T. Myster Ph.D.
• Date Published: December 2010
• Length: 47 pages
• Grant Number(s): 2005-IJ-CX-K016
• Agencies: NIJ-Sponsored
• Publication Type: Research Paper

Annotation

In order to advance the understanding and importance of the analysis of saw marks in bone, this project addressed the lack of research in this field; a related lack of standard terminology, definitions, and protocols for the documentation and analysis of this evidence; and a poor understanding and awareness among the forensic community of the evidentiary value and possibilities of this type of physical evidence.

Abstract

This project developed and presents standard definitions, documentation protocols, and analytical methodologies that enable more accurate and reliable analyses of saw marks in bone and other hard tissues. These efforts are presented in a brief, user-friendly manual that introduces saw-mark analysis to a wide array of forensic processionals. This is the first step in normalizing analytical and documentation protocols for this type of evidence. In developing the content of the manual, the project first relied on the creation, analysis, and documentation of a comparative sample of human remains cut with various serrated tools among a spectrum of the main commercial saw types and classes. The results can serve as a baseline comparative sample for future students and experimental designs on saw-mark analysis. The development of the manual also relied on a dissemination strategy that included a series of lectures (approximately 50 during the project period) delivered by the authors to a variety of forensic professionals. Further testing of the protocols in the manual and the reliability of various proposed markers for the analysis of basic tool parameters (class characteristics) was performed through inter- and intra-observer studies, controlling for the degree of experience and exposure of the participants to the instructional materials. The experimental component of the project also examined some common misconceptions regarding the evidentiary value of some major saw-mark elements.