The phrase "Guilty or Not Guilty" is a legal term, not the title of a specific book or work of authorship. It's the standard question posed to a defendant in a criminal trial, asking them to plead guilty or not guilty to the charges against them.
Therefore, there isn't a single author associated with it.
If you're thinking of a specific book or work, please provide more context or the full title, and I can try to help you find the author.