In this article, we will discuss how to write a formal letter to a judge, along with the proper format and a sample letter. You do not write letters to judges.I am writing this letter on behalf of a family member mine who is presently before you on criminal charges and is due to be sentenced shortly. You cannot write a letter to the family court judge. This would be considered an ex parte communication. What parents and witnesses need to know about character reference letters to the court for child custody. Includes a downloadable sample and template. Writing a character letter for a judge can be a daunting task. Here are nine essential tips for writing an effective sentencing letter. Good character reference letters help the judge understand the defendant as an individual.