Muff Potter's knife

Muff Potter's knife is a large spring-knife that becomes the pivotal piece of physical evidence in the murder of Doctor Robinson. It is first seen when Potter, after helping to exhume a body in the graveyard, uses it to cut the dangling end of the rope binding the corpse to a handbarrow. Moments later, during a struggle between Potter and the doctor, Injun Joe snatches up the knife, and in the instant that the doctor fells Potter with a headboard, Joe drives the knife to the hilt in the young man's breast. After the murder, Joe places the fatal knife in Potter's open right hand, ensuring that when Potter stirs and his hand closes upon it, the weapon will be linked to him. The knife is found close to the murdered man and is recognized by somebody as belonging to Potter, a detail that spreads through the village with telegraphic speed. At the inquest, the Sheriff thrusts the knife before Potter, who would have fallen if not caught, and the weapon's presence is used to cement the false accusation. The knife thus functions as a material object that, through Injun Joe's deliberate manipulation, transforms a circumstantial suspicion into seemingly irrefutable proof of Potter's guilt, and its role in the narrative exposes the fragility of justice when physical evidence is severed from truthful testimony.