Final answer:
The old man in 'The Tell-Tale Heart' is murdered by the narrator, who is fixated on the old man's eye and later confesses due to his guilty conscience.
Step-by-step explanation:
The old man in “The Tell-Tale Heart” is murdered by the narrator of the story. The narrator, driven by his obsession with the old man's “vulture-eye,” plots and carries out the killing silently in the middle of the night. After the deed, he dismembers the body and hides it beneath the floorboards of the old man's room.
The act is not done out of malice or for material gain, but rather as a result of the narrator's disturbed mental state and fixation on the old man's eye. It is the guilty conscience of the narrator that ultimately leads to his confession of the murder to the police.