A character letter to a judge should establish your credibility, paint a full picture of the defendant and be respectful, among other things. A character letter is designed to show support for a defendant in a criminal case.These letters have the potential to influence the court. Introduce yourself in the opening paragraph. A helpful template for writing a character witness letter for court. What parents and witnesses need to know about character reference letters to the court for child custody. Includes a downloadable sample and template.