Well, I think there is a big difference in the stories intentionally. In The Fiend the narrator is depraved and unapologetic and it is clear that he acted intentionally because he liked doing those acts. Here it is ambiguous. It is possible the narrator is actually innocent. If he is guilty then he's not admitting it to us (and perhaps not even to himself). It is possible for us to feel some sympathy for the narrator here. In The Fiend that is almost impossible. Both stories work in different ways and I think it's an intelligent way of covering the same territory using two different approaches.