What a great beginning! The setup might not be so original, but your description really makes it stand out. You did a wonderful job of laying all the relationships out on the table, but the monolouge about the Angel of Death seemed a little forced. You seem to have an adequete knowledge of the legal and scientific proceedings surrounding a murder, despite what you warn the reader in the disclaimer, but even if you don't you speak of it authoritatively enough that it doesn't even occur to the reader to question it. I'm a fan of books like this, so please update soon! I can't wait to see how they catch this guy!

assuming they do, of course...