During a postmortem examination of a stabbing victim, the forensic pathologist observes that the wound on the abdomen is 2 cm in length but penetrates 8 cm deep into the peritoneal cavity. The wound edges show tissue bruising and irregular margins with a small flap of skin. In contrast, a laceration on the scalp is 5 cm long with clean edges and minimal depth. Which finding is most characteristic of a stab wound compared to an incised wound?