Ensuring Admissibility of Your Work as an Expert Witness
Playing by the rules of this legal game will help ensure the admissibility of your work. The goal is to convince people that your opinions are sound. Your investigations and overall work will help you to do just that. After you collect, review and analyze all the information about the technical elements of a case, undertake the required tests, and follow required methodologies, you can form opinions that you can express in an expert report or in testimony.
What you do will help you technically and professionally come to the best opinions. How you do it will help ensure that your opinions are seen as ‘admissible’ and that they will be allowed to be heard in court.
Remember, you are on a playing field called ‘the law.’ You have to play by the regulations in this game:
1. You must be familiar with the facts in the case and the sequence of any events that happened.
2. You must carefully document tests run, observations made, and measurements taken. Contain all results, whether positive or negative.
3. Any demonstrations you plan to use during testimony have to be substantially the same as the events in the case.
4. Any materials you use in tests must be the same as were involved in the case.
5. You must document all steps followed and methods used. Use industry literature and publications to show that the chosen tests or methods are recognized as authoritative in your field.
6. Think About with your attorney whether to use and pay for an independent peer review of your analyses and work.
You very well might do strong investigative and preparatory work, but you are not an attorney so you will not know about all the legal elements of the lawyer’s case. Sometimes you have to meet legal standards that vary from jurisdiction to jurisdiction; explicitly ask your attorney about the standards for your particular jurisdiction so you can choose the tests you run. For example, Maryland, Rhode Island, or California may use different legal tests for insanity. As a psychologist, perhaps, you need that information so you can pose the right questions.
Attorneys will use numerous tactics to raise objections about the validity and admissibility of you, your evidence, and your opinions. Anticipate the following possibilities:







