By James J. Mangraviti, Jr., Esq.


Trials are very risky and very expensive.  Because trials are so expensive and so risky, the vast majority of cases resolve by way of settlement.  Since so many cases settle, expert witnesses are typically far more likely to give their testimony at an expert witness deposition instead of at trial.

What is An Expert Witness Deposition?

An expert witness deposition is a meeting, outside of court, where sworn testimony is taken from an expert witness.  You can expect the attorneys, the witness, and a court reporter to be present at the deposition.  A judge is typically not present.  The deposition can be taken in-person, over the telephone, or remotely by Zoom and the like.

What is the Difference Between A Discovery Expert Witness Deposition and A Trial Expert Witness Deposition

An expert witness deposition comes in two forms – a discovery deposition and a trial deposition.  A trial deposition is a deposition of an expert witness taken by retaining counsel. The trial expert witness deposition is typically video recorded.  The purpose of the trial deposition is to get the expert witness’s testimony into the record and then play or read this recorded testimony at trial in lieu of having the expert appear live.  This is commonly done where the expert may not be available over the trial dates or to save money by not having the expert witness travel to the trial.  In a trial expert witness deposition, the questions asked will mirror those that would be asked at trial.

This post will deal with the discovery expert witness deposition – which is by far the most common type of deposition that expert witnesses will give.  A discovery expert witness deposition is arranged by opposing counsel.  The deposition is typically opposing counsel’s only pre-trial opportunity to question the opposing expert witness under oath – or talk to the opposing expert witness in any way.

Goals of Opposing Counsel During Your Discovery Expert Witness Deposition

Opposing counsel will typically take a discovery expert witness deposition with the following general goals in mind.

Goal #1:  Knock the expert out of the case.  Opposing counsel may try to establish that the expert witness is not qualified, did not follow a reliable methodology, did not base his/her experience on sufficient facts, has not stated their opinions with sufficient certainty, etc.  Per Federal Rule of Evidence 702 and similar rules in effect at the state level, establishing any of the above could allow counsel to obtain an order from the judge partially or completely blocking the expert from testifying.

Goal #2: Find out what the expert witness is going to say and pin them down.  At your expert witness deposition, you can be expected to be asked many types of questions (see below).  All of your answers, given under oath, will be recorded word for word by the court reporter who typically will produce a written transcript of the questions posed and your answers.  Once you answer a question under oath at a deposition, providing a different answer at trial will result in the opposing lawyer impeaching you (i.e. confronting you) with your prior inconsistent deposition testimony.  So, giving an answer to a question at your expert witness deposition will mean that opposing counsel can expect the same answer from you at trial.  If you provide a different answer at trial, you will be confronted with your prior inconsistent expert witness deposition testimony.

Goal #3.  The final overall goal of opposing counsel at your expert witness deposition is to size you up as a witness.  Opposing counsel will want to gain insight as to how effective of an expert you would likely be at trial.  Things counsel could be looking for include:

  • How good are your listening skills?
  • Do you appear nervous?
  • How well do you present yourself?
  • Are you well-prepared?
  • Are you well-organized?
  • Are you evasive?
  • What gets under your skin and pushes your buttons?
  • Do you appear confident?

What You Will Likely Be Asked at Your Expert Witness Deposition

There are a number of areas of questioning that are typically visited during an expert witness deposition.  These include:

Your qualifications.  Counsel will try to get a sense as to how well qualified you are and if there are any vulnerabilities in terms of your education, certification, training, relevant experience, etc.

Your publications.  Counsel will want to know about everything you have written relevant to the case at hand and potentially everything else. If you have not published in an area, counsel can consider attacking your lack of publication at trial.  If you have published, counsel can then scour your writings hoping to find something that is controversial, inflammatory, or inconsistent with your testimony in this present case.

Your Presentations.  Similar to your publications, counsel will hope to find something in your presentations that is controversial, inflammatory, or inconsistent with your testimony in the present case at hand. Counsel may ask you to produce your slides from your presentations as well as a video recording of your presentations if these exist.

Your Expert Witness Experience.  Counsel will want to know about past cases and reports. They will be especially looking to dig up inconsistencies between your past opinions and your opinions in the case at hand.  Counsel will also probe for how much of your work is for plaintiff versus defense and how much work you have done in other cases for the retaining lawyer in this case.  The percentage of your income derived from forensic work is also often asked (to try to establish bias).

Money Questions.  How much you are being paid in this case?  How much have you billed to date?  Are any bills outstanding? How many hours have you put in on the case to date?

Your investigation/research.  Counsel will wany to know exactly what you did and exactly what you reviewed prior to forming your opinions.  The goal here is to hopefully determine that you failed to consider important bits of information and therefore your opinions are compromised.  Was your investigation rushed?  Did you rely on any literature? What are the authoritative texts and journals in your field?

The Influence of Retaining Counsel.  Did counsel spoon feed you research?  Did he/she cherry pick the information you were sent?  Did retaining counsel improperly influence your report or opinions?  Do you 100% agree with any expert witness disclosures that counsel drafted?  Did retaining counsel put any words in your mouth?

Your Opinions.  What opinions will you be offering? What opinions will you not be offering?  Why do you hold each of your opinions?  Would you still hold these opinions if we were to assume different facts? What methodology did you follow in forming your opinions?


You will be far better positioned to excel at your expert witness deposition if you understand the purpose of the deposition, opposing counsel’s goals, and the areas of inquiry you will likely face.

About the Author

James J. Mangraviti, Jr., Esq., has been teaching expert witness deposition skills for over 25 years and has written extensively about expert witness depositions.  He is a Principal of SEAK, IncThe Expert Witness Training Company.  Jim has been retained to train experts for the FBI, SEC, IRS, DoD as well as leading firms, corporations, and professional associations.  He is the co-founder of SEAK’s National Directory of Expert Witnesses, the #1 rated expert witness directory.  Jim can be reached at 978-276-1234 or  For more information on SEAK, Inc. – The Expert Witness Training Company, visit