Morphology of Saw Marks in Human Bone: Identification of Class Characteristics

Accurate interpretation of saw marks on human bone is an essential part of tool mark examination in the forensic sciences, but appears neglected in practice and in the forensic sciences literature. With a basic understanding of saws and principals of cutting action, residual saw characteristics remaining on human bone can be recognized and interpreted.

Two basic areas of saw cut bones are examined. Kerf floors can be examined in false starts and break away spurs. This area of a cut potentially reveals kerf size, striae patterns, and contour differences. Kerf walls, or the cut cross section of bones, reveal striae specifics such as contour, direction of stroke, and patters of cutting action. These areas of cut bone potentially reveal observable and quantifiable characteristics that can be related to predictable saw actions. These characteristics may indicate distances between saw teeth, type and amount of tooth set, tooth and blade shape, manner in which a saw is powered, and direction of saw cut.

These characteristics, utilized individually or in combination, narrow the number of possible saws that potentially create a particular cut. This narrowing of the field of saws allows the examiner to assess the class. subclass, or type of saw utilized in a cut. Ultimately, examination of human bone remains will allow anthropologist to go beyond the descriptive level of analysis to confront modified bone with an appreciation for its potential forensic value.