The character reference letter for court serves the purpose of offering the Judge insights into the Defendant's moral or mental attributes. A character letter is a letter of support from people who know you to help show judges and DAs the positive sides of you.Sample Format for a Character Letter. If you have been asked to write a character letter, this simple template may be a useful guide. In this article, we will discuss how to write a formal letter to a judge, along with the proper format and a sample letter. A character letter to a judge should establish your credibility, paint a full picture of the defendant and be respectful, among other things.