* Right of Publicity: This is the most significant legal hurdle. The right of publicity protects a person's name and likeness from commercial exploitation *after* their death, in many jurisdictions (though the length of time varies). If you're using their name in a way that suggests endorsement or creates a false impression of association with your work (e.g., using a deceased famous chef's name to market a cookbook), you could face legal action from their estate or heirs. The risk is higher if the person was very famous and their name still has significant commercial value.
* Defamation (Libel): Even if the person is deceased, you can't falsely portray them in a way that damages their reputation, particularly if it causes harm to their surviving family.
* Copyright: If the deceased person created a copyrighted work (a book, song, painting etc.) you must obtain permission before using any substantial portions of it in your book. This includes things like quoting them extensively or using specific plot points that are clearly derived from their works.
* Ethical Considerations: Even if legally permissible, using a deceased person's name might be ethically problematic, depending on the context. Consider:
* Sensitivity to the family: Would using this name cause pain or distress to their surviving relatives?
* Misrepresentation: Are you using the name in a way that is misleading or that might create a false impression about the deceased person?
* Appropriation: Are you benefiting unfairly from the deceased person's name and reputation?
In summary: Using a deceased person's name is generally acceptable if you're using it for a fictional character that shares only the name, or as a passing reference in a non-commercial context. However, as the use of the name becomes more prominent, commercial, or potentially damaging to their reputation or family, the legal and ethical risks increase significantly. If you're unsure, it's always best to seek legal counsel. You might also consider changing the name slightly to mitigate any potential risks.