A character letter to a judge should establish your credibility, paint a full picture of the defendant and be respectful, among other things. Sample Format for a Character Letter.If you have been asked to write a character letter, this simple template may be a useful guide. The first paragraph should tell the judge who you are writing to him about and how you know the defendant. You'd also want to say how long you have known her. Character references are a good way to explain to a judge or magistrate all of the person's positive attributes.