Hello, and welcome to English Forums. I searched quickly for matters that concern court appearances in the state of Massachusetts; however, the site referenced here is fairly general.
http://www.businessballs.com/referencesletterssamples.htm
The following information is a quick grab from the web site, OK?
“Certain situations require character reference letters of a more personal nature, such as character testimonials or references relating to court proceedings, or for a position in non-business organisations such as councils, trusts, clubs, or societies. In these cases follow the same principles: do not defame a person in writing or verbally when providing a reference; state only positives or nothing at all. If you need a personal or character reference always ask the writer if it would help to provide them with a draft. Writing reference letters is time-consuming and difficult for many people - offering to provide a draft may sound cheeky, but it is often necessary and much appreciated by the reference giver (incidentally called the 'referee'). Be aware that offering to provide a written character reference relating to a person's court proceedings may lead to your being asked to appear in court as a character witness - so be sure that whatever you write you'd be comfortable stating it in a court of law.
example and template for personal or character reference letter
Date
To whom it may concern
I confirm that I have known (name) for (number) years. (State relationship - social, business, working together in some other capacity, club, activity, project, etc.) At all times I have found (name/him/her) to be (state characteristics - eg, dependable, reliable, hard-working, conscientious, honest, peace-loving, courteous, etc - to be as helpful as possible think about what the reader will most prefer to see, in terms of satisfying concerns, or seeing evidence of relevant required skills or characteristics). I'm happy to provide further information if required (optional). Yours faithfully, etc.”