The short story "The Pit and the Pendulum" by Edgar Allen Poe tells of a man, the narrator of the tale, being condemned to death by black-robed judges. He is locked in a completely dark room which contains a deep pit. Later, he is strapped to a wooden frame and watches a swinging pendulum descend upon him inch by inch. Finally, the walls become hot and move inwards, pushing him towards the pit. At the end, he is rescued as the French army captures Toledo.
The reasons why Poe does not mention the charges for which the narrator is condemned have to do with historical relevance and the effect that this vagueness has on readers.
At the end of the story, Poe clarifies that the narrator has been imprisoned and tortured by the Inquisition. The Inquisition began in the 12th century and lasted for several hundred years. The Spanish version of the Inquisition, which is depicted in this story, may have been responsible for the execution of as many as 32,000 people. The Inquisition was initiated by the pope for the purpose of strengthening the Catholic church by rooting out heretics. In Spain, the Inquisition was mainly a means of persecuting Jews, Muslims, and Conversos. Although Conversos were Jews who had converted to Catholicism, Catholic Spaniards did not trust them. People were not captured by the Inquisition for any crimes that they had committed. They were instead persecuted for being members of minority religions. In fact, once captured, they were not allowed to have legal counsel or face their accusers. It often happened that people would accuse others falsely because they coveted their lands or possessions.
Poe was probably aware of this historical background when he wrote his story. Imagine the trauma of being accused not for a crime, but rather for being a member of a minority religion. If you insisted that you were innocent, you would nevertheless be tortured until you confessed. Even if you confessed, you might be further tortured and then executed.
In not specifying the charges for which the narrator has been brought before the judges, Poe amplifies the trauma and terror of the experience for his readers. Perhaps the narrator himself is unclear why he has been brought in. Perhaps he has been falsely accused but his protestations of innocence have been ignored. The uncertainty heightens the horror of the situation. Because the narrator's personal situation is unclear, readers can more easily project themselves into the story and imagine what it would be like if it happened to them.