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Expert Witness Deposition Tips for Young Lawyers

Steven Maher Harkins and Natassia Kwan


  • Preparation for an expert witness deposition is crucial for success in a case, even if time constraints exist due to condensed discovery schedules or late disclosures by opposing counsel.
  • To prepare, gather the expert's qualifications, publications, testimonial history, and background information through online research, expert witness listing services, and inquiries to other attorneys.
  • Use tools like timelines, charts, and diagrams to supplement your deposition outline and enhance your understanding of the case, but be mindful of the rules governing the sharing of expert reliance materials.
Expert Witness Deposition Tips for Young Lawyers
Frances Twitty via Getty Images

Expert witness depositions represent one of the most crucial steps in any case. Whether you are handling the deposition directly, supporting another attorney taking the deposition, or merely preparing the expert’s witness file and/or an outline for the deposition, remembering a few key points will set you up for success.

Starting Early

Although it would be ideal, we do not always have ample time to prepare for an expert witness deposition. Condensed discovery schedules (see generally E.D. Va. L.R.) late disclosures by opposing counsel (see Lee v. Smith, No. S18G1549 (Ga. Feb. 10, 2020 slip. op.) (trial court’s exclusion of an expert witness solely due to identification after the deadline set by a scheduling, discovery, or case management order constituted an abuse of discretion)), and a host of other extenuating circumstances may prevent you from ramping up your investigation and starting preparation right away. But once the expert is disclosed, every day until the deposition is an opportunity to gather that hard-to-find publication, go one level deeper on your background investigation, and track down another transcript that may have important prior testimony. Also, your own experts may be able to suggest lines of questioning that you may not have thought of on your own given their familiarity with the complex subject matter, so consider engaging them early in your preparation process.

Preparing the File

Your team needs to know the expert’s qualifications, prior publications and written work, and testimonial history inside and out.  

  • Publications: Many experts will have an online profile where they list publications and possibly presentations and/or areas of expertise. Some experts are not careful about how they describe themselves on websites or listings with expert search services, so these may be fertile ground for exploration. Research portals can also pull up academic articles, books, and other materials they have authored, and if the expert has spoken to industry groups or presented at conferences, their slide decks may be available online. It takes time to gather all this information, sort through what is relevant to your case, and then prioritize the list. Build in enough time for you to receive all the publications and read through them. If you are put in a time crunch or need to get another team member up to speed, a list focusing on the highest priority material can be invaluable.  
  • Background investigation: Dig deep into the expert’s background via online resources, social media, reporting services, expert witness listing services, and inquiries to other attorneys. Ask other experts or people in their field if they know anything about the expert. For example, in one recent case, we discovered through our expert that a key physician witness in plaintiff’s case had an unsavory reputation in her niche medical community due to questionable activity at industry conferences.  
  • Prior testimony: Many experts have testified before. In most cases, during discovery, you will be able to obtain a list of actions where the expert has testified or been retained prior to their deposition. From this you can determine whether he typically testifies for plaintiffs or defendants or whether he has a prior relationship with opposing counsel. However, transcripts of his testimony will not usually be found on publicly-available resources, so a comprehensive collection will involve reaching out to lawyers involved in those prior cases, as well as searching through services such as IDEX and pulling information available on legal research sites like LexisNexis and Westlaw. If the expert has been challenged before in federal court, excerpts of his deposition and/or report may even be filed as an exhibit to the motion to exclude and may be available on Pacer. Build in time to reach out to other attorneys, obtain all prior testimony, and review to see if they are relevant to your matter and if the expert’s testimony in prior cases would have any bearing on, or perhaps expose an inconsistency in his testimony as related to your case. This is also a great opportunity to ask for insight on the expert from colleagues who have dealt with the expert before.

Using Outlines and Other Aids

Expert witnesses present a unique challenge to depose. They often begin with a stronger understanding of their specialty subject areas than the deposing attorney and, in many instances, can level the playing field further if they have substantial prior experience testifying. In addition to your deposition outline, which should be carefully organized and incorporate your potential exhibits, consider supplementing your knowledge base with other useful tools.

  • Chronology/timeline: A detailed chronology or timeline is invaluable. This may be a chronology of medical records pertinent to the expert’s opinions, a regulatory chronology for a federally-regulated product, or a timeline of product complaints in the event of a recall. You cannot duplicate the years of training and education an expert has in his or her field. However, a chronology will help you to master the facts of your case in a way most experts will not have the time or inclination to replicate.
  • Charts/diagrams: Consider organizing or supplementing your expert file with charts. These can be done in accordance with your chronology or timeline, by topic, or another way in line with the goals of your deposition. For example, grouping the expert’s literature by topic, or preparing a chart listing possible areas that the expert may testify about can prove helpful down the road to collect and sort your information. These same charts or diagrams may later be useful at trial as the starting point for demonstratives.

Note that when using these tools, be thoughtful about how and whether to share them with your expert. Federal and state rules and laws govern what expert reliance materials are discoverable, so consider those thoroughly before deciding what to provide your own expert witness. Competent opposing counsel will try to obtain any chart or aid included in the expert’s packet of review materials, but the attorney preparing the witness for deposition can often benefit from referring to these documents during a prep session without actually putting them in front of the witness or adding them to her file.