In detective novels, the point is often that the reader gets enough information to solve the crime themselves. This "puzzle" aspect of detective novels is part of the attraction.
Often the difficulty for humans is to keep track of all the variables - events, items, motivations. An AI would have an easier time keeping track of all the details, but would rely on real-world knowledge to prevent making crazy mistakes. For example, if it was stated that a character took the train, the AI would need to know that this is a method of transportation - that it changes the location property of an agent over time.
Has an AI ever been able to solve a detective mystery?