© 2025 SEAK, Inc.

By James J. Mangraviti, Jr., Esq.

Deposing an expert witness is critical for both preparing for trial and determining the settlement value of a case. The below is an outline of deposition questions for expert witnesses.

Outline of Deposition Questions for Expert Witnesses

1. Expert Witness’ qualifications:
    a. expert witness’s educational background;
    b. expert witness’s grades;
    c. expert witness’s degrees;
    d. expert witness’s dates of attendance and degrees;
    e. gaps in education;
    f. expert witness’s additional training;
    g. expert witness’s continuing education courses;
    h. expert witness’s relevant practical experience;
    i. expert witness’s membership in professional organizations;
    j. expert witness’s level of activity in these organizations;
    k. expert witness’s certifications; and
    l. if these certifications were earned, bought, or if they were grandfathered-in.

2. Publications:
    a. What articles, book chapters, books, reviews, or abstracts written?
    b. Where and when were they published?
    c. Were there co-authors?
    d. Are any writings pending publication?
    e. Have any writings been rejected for publication?
    f. Does the expert witness have copies of these publications?
    g. Where has the expert witness blogged?
    h. What aliases does the expert witness use to post online?

3. Relevant practical experience:
    a. What relevant practical (hands-on) experience does the expert witness have with regard to the issues in this case?

4. Litigation experience:
    a. Has the expert witness testified in a lawsuit before?
    b. Where, when, and how often?
    c. Did they retain your old transcripts and reports?
    d. Do they retain their old 1099 forms from law firms?
    e. How much of their income is derived from testifying and preparing to do so?
    f. Do they advertise their services? If so, where, when, and how?
    g. How did they get into this case?
    h. Have they served as an expert witness for this lawyer or firm before? If so, how often?
    i. Which past cases have involved issues relevant to this case?

5. Research:
    a. Has the expert witness ever done research relevant to the subject at issue?
    b. If so, when, where, under what circumstances, and for whom?
    c. Were the results published and, if so, where can I get a copy?

6. Probe for bias:
    a. Relationship (personal and professional) with retaining counsel or party?
    b. Prior inconsistent testimony?
    c. Compensation in prior cases?
    d. Previous testimony for the same party?
    e. Expert witness income?
    f. Memberships in organizations with an agenda?
    g. Direct or indirect financial interest in the case (such as a lien or outstanding bill)?
    h. Willingness to take plaintiff’s/defense cases?

7. Learn factual assumptions:
    a. What assumptions has the expert witness made?
    b. Why did they make that assumption?
    c. Why did they consider this a reasonable assumption?
    d. How would their opinion change if that assumption was to change?

8. Opinions:
    a. What the expert witness will and will not be testifying to?
    b. How, specifically, did the expert witness arrive at their opinions?
    c. The facts and assumptions on which the opinions are based?
    d. The methodology used to form the opinions?
    e. When the opinion was first formed?
    f. Degree of flexibility in the opinion?
    g. Degree of certainty in the opinion?

9. The Expert Witness’s Report:
    a. Did anyone help the expert witness write the report?
    b. Did the expert witness use AI to help with any part of the report?
    c. Did the expert witness share draft reports with retaining counsel?
    d. Did they retain previous drafts of the report?
    e. Did the expert witness copy any language in their report from other sources?
    f. Can the expert witness define all terms used in the report?

10. The Expert Witness’s CV:
    a. Accuracy
       i. Was their CV 100% accurate when written?
       ii. Has anything changed since the CV was written?
      iii. Was the CV 100% accurate when presented to counsel?
    b. Timeline and gaps
       i. Have they listed their inclusive dates of work, education, and other activities?
       ii. Do they have gaps in their CV timeline?
    c. Prior CVs
       i. Are their prior CVs consistent with their current one?
       ii. Are there material changes, omissions, or alterations that open lines of inquiry?
    d. Multiple CVs
       i. Do they have more than one current CV?
       ii. Online/LinkedIn CV different? Why?
       iii. Are their multiple CVs prepared and used for different clients?
    e. Professional societies and certifications
       i. Are the affiliations listed current?
    f. Writings
       i. Are the dates, titles, and claims to authorship accurate?
    ii. Have they listed co-authors?
    iii. Have they exaggerated the importance of the publication or your role in it?
    g. Previous cases
       i. Does the expert witness list the cases you have worked on?
       ii. Does the expert witness list the cases’ outcomes?
    h. Dating
       i. When was the CV prepared?

11. Authoritative texts/learned treatises:
    a. Did the expert witness rely on any texts, journals or references?
    b. What is in their library?
    c. What do they subscribe to?
    d. What does the expert witness read/keep up with?
    e. What have you cited for references in previous reports and work?
    f. What texts or sources does the expert consult regarding questions in your field?
    g. Is such and such a text/journal/website/code/standard authoritative?

12. Expert Witness Fees and billing:
    a. Fee agreements?
    b. Hourly or other rates?
    c. Rates for depositions or trials?
    d. Amount of your bill to date?
    e. Outstanding bills?
    f. Anticipated future billing?

13. Forensic/expert witness income:
    a. The amount of money they make from expert witness work?
    b. The percentage of total income their forensic expert witness work represents?
    c. The percentage of time they spend working for attorneys?

14. Case Involvement:
    a. Who first contacted you?
    b. When were they contacted?
    c. How did counsel find them?
    d. How were they contacted?
    e. When did they “accept” the case?
    f. When did they permit themselves to be designated as an expert?
    g. What work have they done in the case? Areas of inquiry could include:
       i. What was your task(s)?
       ii. Who gathered the information for you?
       iii. What did you rely on others to do?
       iv. Which technical publications did you consult?
       v. What scientific technical equipment or machinery did you use?
       vi. What industry or professional standards were used?
       vii. Which records and documents were reviewed? When were they reviewed?
       viii. Did you use artificial intelligence or computers to form your opinion, write a summary, or for anything else?
       ix. Examination: What was done and when was it done?
       x. Testing: What was done, when was it done, and what were the results?
       xi. Is all of this work reflected on your bills and invoices?
       xii. What additional work do you anticipate doing prior to the trial?

15. Materials or records the expert witness received/reviewed:
    a. Who provided each record?
    b. When were they provided?
     c. Which of the following were provided?
       i. Correspondence
       ii. Reports
       iii. Messages
       iv. Notes
       v. DVD, thumb drives, e-mails, or FTP files
       vi. Police reports
       vii. Investigative reports
      viii. Medical and hospital records
       ix. Literature
       x. Tables
       xi. Standards
       xii. Contracts
       xiii. Photographs
       xiv. Video Recordings
       xv. Research
       xvi. Test results
       xvii. Did the expert read all the documents? How carefully?
       xviii. Did the expert use AI to review, organize, dedupe, or summarize the documents?
       xix. What documents or materials that they did not have access to would the expert have wanted to have access to?

16. Daubert/Frye/Rule 702:
Rule 702. Testimony by Expert Witnesses
A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if the proponent demonstrates to the court that it is more likely than not that:
(a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the   evidence or to determine a fact in issue;
(b) the testimony is based on sufficient facts or data;
(c) the testimony is the product of reliable principles and methods; and
(d) the expert’s opinion reflects a reliable application of the principles and methods to the facts of the case.

    a. The “facts or data” you based your opinions on?
    b. Your “principles and methods”?
    c. Is their methodology generally accepted in your field?
    d. The theories and techniques you used and how and when they have been tested?
    e. Did they build a prototype?
    f. The error rate or potential error rate?
    g. Peer-reviewed literature that supports the expert’s conclusions and opinions?
    h. Peer-reviewed literature that undercuts the expert’s conclusions and opinions?
    i. The reliability of the scientific data used and whether it is generally accepted in the scientific community?
    j. Whether the opinion is for litigation only? Did the expert’s theory exist prior to this litigation?
    k. What standards and controls did the expert use?
    l. Did the expert witness extrapolate? What was their sample size?
    m. How did they conduct their research?
    n. Did they consider alternative theories?
    o. Did they rule out alternative theories? Why?
    p. Who funded the “science” the expert witness based their opinion on?

James J. Mangraviti, Jr., Esq., has trained thousands of expert witnesses through seminars, conferences, corporate training, training for professional societies, and training for governmental agencies including the FBI, IRS, SEC, NYPD, Secret Service, and Department of Defense.  He is also frequently called by experts, their employers, and retaining counsel to train and prepare individual expert witnesses for upcoming testimony.  Mr. Mangraviti assists expert witnesses one-on-one with report writing, mentoring, and practice development.  He is a former litigator who currently serves as Principal of the expert witness training company SEAK, Inc. (www.testifyingtraining.com).  Mr. Mangraviti received his BA degree in mathematics summa cum laude from Boston College and his JD degree cum laude from Boston College Law School.  Mr. Mangraviti has designed dozens of expert witness training programs and has personally taught experts in a group setting over 250 times since 1997. He is the co-author of thirty books.