By: Jessica Mahon Scoles, Esq.

An expert witness who will be testifying, whether it is at deposition or trial, should be prepared to deal with these 10 routine areas of inquiry.

1. Bias

Experts will be cross-examined about their real or imagined bias. Counsel who can demonstrate or raise doubts about the expert’s bias can quickly destroy the credibility of the expert. Experts are well advised to form honest, fair, and unbiased opinions and to prepare in advance to address questions about any perceived bias.

2. Curriculum Vitae

Experts who exaggerate their credentials or who have mistakes on their CV are less likely to be believed. Why should the judge or fact finder find an expert credible if they cannot even get their own CV right? Experts will want to make sure their CV is bullet-proof and mistake free.

3. Qualifications

If counsel can show or imply that the expert is not really qualified to testify on the issues, the expert may be disqualified by the judge or have their opinions given little weight by the jury. The expert should only accept cases in areas where he/she is truly an expert and well-qualified.

4. Methodology

Counsel will now frequently challenge the expert’s methodology in an attempt to Daubert them out of a case. Experts will want to follow a generally accepted methodology when forming their opinion. Experts should be prepared to answer questions about their methodology in a comprehensive and articulate fashion.

5. Prior Statements

Experts should be prepared to answer any and all questions about prior statements they have made in reports, articles, blog posts, prior cases, depositions, and trials. Failure to do so effectively can destroy their credibility.

6. Opinions

Counsel will aggressively challenge the expert on all aspects of their opinions, including qualifications, research performed. Investigation, methodology, language used, degree of certainty, etc. When counsel can demonstrate flaws in the opinion, or their scope, the expert can be compromised.

7. Fee Questions

Counsel will inquire about the amount of fees, the justifications for “large fees”, and whether they are reasonable. Experts need simple, non-defensive answers to any and all fee questions.

8. Interaction with Retaining Counsel

Experts can expect counsel to try to imply or demonstrate that counsel unduly influenced the expert and the conclusion they reached. A transparent practice by the expert regarding opinion and report preparation is the best way to counter any of these implications.

9. Investigation

Counsel will try to attack the expert for their rush to judgement, sloppy, or limited investigation. A thorough and honest investigation is the best antidote to counter this attack.

10. Reports

Expert should expect and prepare for close, intensive questions about each and every word in their report. The jury will not find an expert credible if the expert cannot explain or defend the report and its conclusions.


Expert witnesses should intensively prepare to answer all questions about the 10 areas of inquiry they are likely to face at depositions/trial.

About the Author

Jessica Mahon Scoles, Esq. is a civil litigator who has worked with expert witnesses in a variety of cases. She currently serves as Vice-President of The Expert Witness Training Company SEAK, Inc. ( Prior to joining SEAK, Jessica practiced law at a boutique firm in Boston (where she was named a Super Lawyers Rising Star), was a law clerk for Hon. Donald L. Cabell of the United States District Court for the District of Massachusetts, and was a litigation associate at the national law firm of Bingham McCutchen, LLP. She received her BS degree in Film Production cum laude from Boston University and her JD degree summa cum laude from Loyola Law School.