Areas of Inquiry for a Defense Expert Witness

The following are potential areas of inquiry (with some sample deposition questions) when taking the deposition of a defense expert witness.  For a comprehensive list of expert witness deposition questions, please see the text How to Prepare Your Expert Witness for Deposition.


Please tell me all the ways in which you promote your expert witness practice.


Hired Gun

Are you a professional expert witness?

Who should prevail in this lawsuit?

Interest Groups

Please tell me every association or interest group you belong to.


Prior to your involvement in this case, were you or anyone you know acquainted with anyone at [law firm that hired you]?


What percentage of your legal consulting engagements are for plaintiffs?

What percentage of your legal consulting engagements are for defendants?

Where are the records to support these percentages?


What political party, if any, do you belong to?

Do you support tort reform?

Repeat Client

Have you been retained to work for this company before?

Have you been retained by this law firm previously?

Have you been retained by this attorney previously?

How much money have you generated in your career as a result of work for firm/lawyer/company?

How many unfavorable opinions do you think it would take before firm/lawyer/company stopped hiring you?



Professional Expert

How many legal matters do you currently have open?


Areas of Expertise

Are all of your areas of expertise listed on your CV?


Which school did not accept you?

Expert Witness Work

Have your testimony or opinions ever been limited in any way by any judge, court, or administrative body?


Have you ever had a license suspended or revoked?


Is the list of your publications on your CV accurate?

Have you ever submitted anything for publication that has not been published?

Do you blog?

Where can we find your blog?


Is the list of presentations you have complete and accurate?

Did you prepare slides/PowerPoints for that talk?

Document Retention

Do you still have copies of any of your past deposition transcripts?

Do you still have copies of any of your past expert witness reports?


Are you ethical?

Is it important to be ethical?


Is this your complete file?

Has anything been removed from this file?



Have you ever been named as a defendant in a lawsuit?

Past Addresses/Associations

Please tell me every address you have lived at since you turned 18.

Personal Relationships

Are you currently romantically involved with anyone?

Prior Bad Acts

Have you ever had any complaints filed against you?

Social Media

Please tell me every LinkedIn group you belong to.



Did you have a budget for your work in this case that you had to live within?

Changed Circumstances

When did you inspect X?

Other Persons

Please tell me everyone you have discussed this case with.


When were you first contacted regarding this case?

What Reviewed

Did you receive all the documents in this case?


Please tell me everything you do to market or promote your expert witness practice.


Please tell me all the expert witness brokers/referral services you are listed with.

Direct Marketing

Have you ever sent any emails to help get new expert witness business?


Do you maintain a list of past cases/inquiry?


Are you responsible for the contents of your web page?


Alternative Explanations

Did you consider alternative explanations?


Please do the math for me.  Run that calculation on this piece of paper.

Computer Assistance

Did you use any computer programs to assist you?

Error Rate

What is your margin of error?


Did you extrapolate at all?


Please tell me all the evidence you know of that supports the premise that your field of study produces reliable conclusions.

General Acceptance

Is your methodology generally accepted in your field?

Opinion for Litigation

Did you use the same methodology you have used in matters not involving litigation?

Peer Review

Please tell me every peer-reviewed article that supports your opinion in this case.


Do you have a protocol for forming opinions in these types of cases?

Prototype/Alternative Design

Did you formulate an alternative design?


Is your methodology testable?


Did you take any notes during your work on this case?


Degree of Certainty

Are all of the opinions you expressed being expressed by you to a reasonable degree of certainty?

Lock Down

Please tell me all of the opinions you will be offering in this case.


Is your opinion subjective?

Willingness to Change Your Opinion

Tell me all the circumstances under which you’d be willing to change your opinion.

Other Experts

Are there experts who are more qualified than you in this area?



Did you ever fail any such test?

Continuing Education

Is it important for you to take continuing education to stay current in your field?


Please summarize all of the practical, hands-on experience you have in the field of X.


What exactly are you an expert on?


Do you keep current with the literature in your field?


Does this report represent your best work?

Did you share any of the drafts with anyone else, including retaining counsel?

What assistance did retaining counsel provide to you with regard to your report?

Retaining Counsel

How did retaining counsel come about hiring you in this matter?


Have you ever written any letters to the editor?

Have you ever written any op-eds?