Is the Law Just or Unjust?

Prosecution is not imbued with any obligation to enforce laws that they don't think are just. In the situation when can you resortike, resort to some theory of authority or ethics? If it's unclear whether a person should be punished for something, maybe you're not sure whether the law is just or unjust. And i generally think if you're unsure, you should probably err on the side of not punishing a person.