Near the end of the story, police arrive at the narrator's home. They tell him,
A shriek had been heard by a neighbour during the night; suspicion of foul play had been aroused; information had been lodged at the police office, and they (the officers) had been deputed to search the premises.
In other words, the police have been dispatched to discover the source of the cry that the narrator's neighbors heard. The narrator actually encourages them to search! He assures them that the cry was his own and that the old man is out of town. He brings chairs into the very room in which the old man is buried and asks the policemen to sit down. He declares that they "were satisfied. [His] manner had convinced them. [He] was singularly at ease." However, it is at this point, when they are convinced that there is nothing to discover, that the narrator begins to become unhinged, almost as though he craves discovery. His symptoms sound like guilt: his head begins to ache, his ears ring, he grows pale, he becomes agitated, his breathing accelerates, and so on. He believes that he hears the old man's heart beating beneath the floorboards, though this is likely also another symptom of his guilt (it is his own heart beating so quickly and loudly to him). The narrator soon confesses to the crime he's committed, as he is sure the police have already discovered it. Although he does not appear to recognize his guilt, the narrator's behavior provides evidence that he does, in fact, feel guilty for his actions and that this guilt compels him to crave discovery.