Morse Hudson is one of the sellers of the Napoleon statues that are the unfortunate victims of a crime spree. Hudson's scene with Holmes is notable because we only hear Hudson's side of the conversation and his responses to Holmes's questions (Six Napoleons.81). In this conversation, Hudson expresses some political sentiments and gives us some insight into how a lot of people viewed foreign immigrants in a somewhat negative light in this era.
Mr. Barnicot is the former owner of some Napoleon statues. We say former because his statues were the first ones smashed during the statue-smashing spree. The unusual nature of the case, and the fact that both of the Napoleon busts owned by Barincot were destroyed, is what prompts Lestrade to bring Sherlock Holmes in on the investigation.
Horace Harker is yet another Napoleon statue owner that gets involved in the case. Unfortunately for Horace, not only is his Napoleon statue smashed, but a man is killed on his doorstep. Harker is a journalist and his conversation with Watson and Holmes give us some great insight into journalism as a profession in the 1890s, as well as communication themes in these stories. (For more on that, check out the quotes on "Language and Communication.") Harker is shaken up by the experience, but like many victims and witnesses in these tales, he still manages to tell a very coherent story. Harker also insists that he's too shaken up to speak before he does so rather eloquently, and this begs the question as to how much Watson himself intervenes here and "cleans up" people's narratives after the fact in the stories.
Beppo is one of the most unusual criminals in these stories. An Italian immigrant, Beppo is also involved in the Mafia. He hid a stolen pearl in a bust of Napoleon and, after he gets out of jail for another crime, he goes on a crime spree in an effort to find the pearl. Beppo is a focal point for a lot of dialogue regarding race in the 1890s. He's continually described as "ape-like" in appearance, which references a lot of eugenic ideas. Eugenics was a "racial-science" that was popular in the late nineteenth century; in eugenics theory, non-white people were "lower" on the evolutionary ladder and were thus more closely related to apes. Unfortunately, eugenics was considered respectable by a lot of people, and it helped to spread a lot of harmful ideas.
Given the racial views on Beppo, it's no mistake that he doesn't have a last name and never speaks during the course of the story. He's portrayed practically like some sort of violent creature, and not an actual person.Want to learn more about 19th century eugenics? Check out these sites: an online book about literature and eugenics, a biography of the founder of eugenics in Britain, Francis Galton, and this PBS page on Darwin, which also has information on eugenics.
Holmes and co. catch Beppo at Josiah Brown's house, after Holmes makes the connection between the six Napoleon busts and Beppo's crime spree. Josiah was the owner of one of the two remaining busts
Hill is the name of the police officer who is described by Lestrade as an expert on the Mafia and the Italian Quarter of London. It's interesting that the London police were beginning to specialize in certain areas, much like cops today are often homicide detectives or specialize in gangs. Hill shows how the London police were really modernizing in this time period and he also highlights how foreign immigrants played a major role in London in this era.
Sandeford is the owner of the Napoleon bust in which a famous black pearl is hidden. Or he was the owner at any rate. He sells the bust to Sherlock Holmes, not realizing there is anything of value inside. Sandeford is definitely a nice guy, because he tries to convince Holmes that he is overpaying him for the statue. At least Holmes paid Sandeford a good amount of money for his statue, though it certainly didn't come close to the value of the pearl.
Pietro is the name of the man who was found murdered outside of Horace Harker's house. Holmes eventually uncovers Pietro's connection to the bizarre case when he discovers his relationship to Lucretia Venucci and his connections to the Italian mob and Beppo. Beppo definitely killed Pietro, but we never find out if the two were rivals or partners who had a falling out over the fate of the black pearl. Holmes doesn't seem to care at any rate since he caught Beppo. It's interesting that Holmes lets these details slide, since he usually goes out of his way to get a full confession. The fact that he had a solid case against Beppo without such information may account for his lack of curiosity here.
Lucretia is the sister of the murdered Pietro. She is also a suspect in another major crime: the theft of the Borgia black pearl. At the time the pearl was stolen, she was the maid of the princess of owned it. Holmes worked the case initially and suspected Lucretia, but could never prove anything.