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. The walls of the stab tracks were exposed and documented by photography, cast with dental impression material, and the casts photographed. Striations were identified in all of the tissues in every stabbing, but their consistency and quality varied between tissues. Striations were most easily seen in liver, heart, and aorta. Tool mark striations in soft tissues other than cartilage have not been described in homicidal stabbings, likely because they have not been sought. We suggest that the walls of stab wound tracks should be exposed, and tissue striations should be sought as a means of identifying the weapon as having a serrated blade.