Tool mark striations in pig skin produced by stabs from a serrated blade.

Stab wounds produced by serrated blades are generally indistinguishable from stab wounds produced by non-serrated blades, except when visible tool mark striations are left on severed cartilage. Using a pig-skin experimental model, we explored the possibility that similar striations may be left in skin. Stabs into pig skin were made using a straight spine coarsely serrated blade (121), a drop point finely serrated blade (20), a clip point irregular coarsely serrated blade (20), a drop point coarsely serrated blade (15), and as controls 2 non-serrated blades (40).

An experimental model of tool mark striations in soft tissues produced by serrated blades.

Stab wounds produced by serrated blades are generally indistinguishable from stab wounds produced by non-serrated blades, except when visible tool mark striations are left on severed cartilage. We explored the possibility that similar striations may be produced on the soft tissues of internal organs. Loin of beef, bovine kidney, and pig heart, liver, and aorta were each stabbed 20 times with a coarsely serrated blade.

Class characteristics of serrated knife stabs to cartilage.

A total of 136 stab wounds were made in cartilage with 8 serrated knives and 72 stabs with 4 nonserrated knives. The walls of the stab track were documented by photography, cast with dental impression material, and the casts photographed. Staining the translucent cartilage surface with blue or green food dye improved photography.