Write an epilogue to the story "The Cask of Amontillado" in which a case against Montresor finally comes to trial. In your epilogue, provide the prosecuting attorney’s closing argument, reminding the jury of any evidence that proves Montresor’s guilt. Then provide the defense attorney’s closing argument. What is the jury’s final verdict?

In an epilogue, you might include that Montresor's story was overheard by someone standing outside the bedroom door while Montresor was confessing his crime to the priest. This person (you will have to decide who this is) would go to the police or authorities. The police would go into the catacombs, find the wall Montresor had made, and take it down to discover the skeleton chained there.
Montresor would go to trial for murder. Since this story is set in a time before modern forensics, there would be no DNA testing or other modern tools to help determine the body was Fortunato's.
In the closing arguments, the prosecution would argue along the lines that, although there were no witnesses to the deed, the person who overheard the confession was able to quickly lead authorities to the body based on what Montresor said he had done. They would mention that Fortunato disappeared right after the festival, and that Montresor had mentioned and that Fortunato's body was never found. They might perhaps argue that the skeleton was the right height to be Fortunato, and that the rotting jingling cap on his skull was consistent with the one he wore the night he disappeared. Other evidence, such as perhaps an abandoned wine bottle, would be consistent with Montresor's story, proving that the body was Fortunato's and Montresor had murdered him.
The defense would almost certainly argue that the confession was a symptom of Montresor's insanity and that he, perhaps suffering from dementia in old age, was confusing stories he had heard of a corpse being chained in the catacombs hundreds of years before with something he thought he had done. They would say Montresor was suffering from delusions of grandeur and wanting to take credit for another person's crime. They would point out that nobody could come up with any wrong Fortunato had done to Montresor that would motivate such a horrible revenge.
The jury would then have to evaluate the evidence. Could the wall built in front of the corpse be hundreds of years old? Or must it be newer? How could experts tell? Would a cap have survived hundreds of years without decomposing? The evidence would, it seems to me, point to Montresor's guilt, but since this is a Poe story, you would have to decide if justice would prevail. Would Montresor would be convicted, or would there be a more macabre ending? (Hint: in Poe stories, grim though they can be, criminals often are brought to justice.)
You would have decide what time period the story is set in. If you put it in Poe's time, there might be a police force; in an earlier time, it might be magistrates going to find the body. Also, go through the story again, find more details about what happened to build your case (did anyone who is still alive, for example, see Montresor and Fortunato leave the party together?), and try to stick as closely as possible to what the story says.