Haunted Bagpipes

I listened to this episode of Sherlock Holmes on satellite radio on the way to work. Starring Tom Conway and Nigel Bruce, and featuring an appearance by arch-enemy Professor Moriarty. It explains why Moriarty became a criminal. He had been an assistant to a doctor working on a cure or prevention for a fatal disease, and society would not let them use live subjects for their experimentation. He resented it so much that he turned against humanity. Whether this explanation was ever set forth by Conan Doyle, I do not recall.