How to Write a Letter of Testimony

By Jayne Thompson - Updated June 05, 2017
Man working writing a letter at desk

While courts prefer that a witness gives evidence in person, they recognize that personal attendance isn't always possible. Where state law permits, judges will often accept written testimony from witnesses. A letter of testimony contains different information depending on whether you're giving evidence as an eyewitness or as an expert.

Start Your Letter of Testimony

Start by addressing your letter to the presiding judge of the court where the case is being heard, followed by the name of the case and case number. Write the date. Address the letter to "Your honor." The first few lines should include your full name, age, address, county of residence and telephone number. If you're giving testimony as an eyewitness, mention your relationship to the plaintiff or defendant. Don't worry about formatting the letter in a particular way. As long as the information is there, your testimony will be effective.

Include Your Expert Credentials

If you're giving testimony as an expert witness, it's important to establish your professional credentials and why you are qualified to give testimony in this case. List your work, professional and education credentials and the name of your current employer. If your credentials are lengthy, attach a separate list or resumé. The more compelling your expertise, the more likely the judge is to respect your opinion.

Clearly Communicate the Issue

In the body of the letter, provide the details of the topic on which you are testifying.

An eyewitness should establish how, where and when he saw important events. For example, you might write something like "I was driving north along Palm Avenue on March 14th 2017 when I saw the Defendant run a red light."

An expert witness should write down what she did to be able to render her opinion – "On March 14th 2017, I examined the brakes on Mr. Smith's Ford Fusion and subjected them to the following tests." If possible, your expert testimony should include a conclusion, an estimate of the cost to fix the problem and other relevant facts.

Choose Your Language Carefully

The primary focus of witness testimony is to clearly and concisely communicate the facts. Make sure that your information is logical, reasoned and rational – you can use numbered paragraphs if this helps to organize your thoughts. Avoid emotional language as your letter will lose credibility. It's important to let the facts speak for themselves.

Certify That Your Statement is True

At the end of your letter, write the following statement:

"I declare under penalty of perjury under the laws of the State of [state] that the above is true and correct."

The precise wording differs between jurisdictions, so check the requirements with the court. Review the testimony and make sure that it's consistent and includes only details that you actually saw or heard. Sign and date the letter of testimony, and mail or deliver it to the judge. If you live out of state, you may have to sign the statement in front of a notary public. Telephone the court clerk to check the requirements.

About the Author

Jayne Thompson earned an LLB in Law and Business Administration from the University of Birmingham and an LLM in International Law from the University of East London. She practiced in various “big law” firms before launching a career as a commercial writer. Her work has appeared on numerous legal blogs including Quittance, Upcounsel and Medical Negligence Experts. Find her at

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