Advanced Expert Deposition Techniques – Moving Beyond the Basics

Expert Witness Depositions

Depositions are arguably the most important method of discovery with respect to the testimony of expert witnesses. However, every case is unique and the testimony of expert witnesses is anything but monolithic. As a result, an attorney seeking to depose an expert witness should be prepared to do more than simply read from a list of previously composed questions. In fact, reading from a list of questions can result in the attorney being unable to react appropriately to unexpected answers from the deponent. This means that attorneys should be aware of some specialized deposition techniques which go beyond the basic skills involved in conducting a deposition of an expert witness.

Communications between Attorney and Expert

In many jurisdictions, it continues to be the case that communications between an attorney and an expert witness are not privileged because the expert witness is not your client. If this is the case, that means you can ask questions regarding what statements were made by the attorney during the hiring of the expert and whether or not the attorney attempted to coach the expert into giving a one-sided opinion. If the expert witness is harmed enough, it could mean that the case will settle on the spot.


Expert witnesses rise and fall by the scientific and technical processes that they utilize. However, many times an expert may want to just give their opinion without citing any medical journals or peer reviewed studies as the basis for their opinion. Here, you want to make sure to nail down where they learned the method they are using, how it was applied, how many other experts in the field use it, what the error rate is, and whether the method has been peer reviewed. If they cannot answer those questions, it makes their opinion worth less weight. Another possibility is the reasoning that they chose one method over another if the method chosen conveniently results in a more favorable opinion for their client.

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Bias is the number one thing to address in an expert witness deposition. If their credibility is gone through a clear bias, the opinion can be worthless. Frequently, the individuals who act as expert witnesses in big cases may be professionals that testify in cases for a living. This is why it is important to get into how many other cases they have testified in and how many times they have had a pro-plaintiff opinion and how many times they have had a pro-defendant position. For example, if they are a doctor who always recommends thousands of dollars in medical treatment to make money from the insurance company, that should seriously inhibit their credibility.

Attorneys should always get into the payment structure of an expert because it is always relevant and shows the expert witness’s bias. Arguably, the larger the fee the individual is getting, the more incentive they have to potentially stretch the truth to support the position of the side that hired them.

Dealing with Evasive Answers

The most crucial skill an attorney needs for deposing an expert witness involves what to do when the expert gives empty answers to your questions. This could involve answers stating that the witness does not recall something, conclusory language, or refusing to give specific answers to questions which are narrowly tailored. If an expert does not recall the methods that they used or the basis for their opinion, this is a major opportunity to highlight the opposing expert’s shortcomings. One should then use their lack of recollection against them in that it undercuts the credibility of their report and their opinion. Other experts will attempt to answer questions in a conclusory manner to avoid talking specifics. If this occurs, the attorney taking the deposition should not be afraid to repeatedly ask the expert witness the basis of how they came up with their opinions in the case. The expert witness should be forced to clarify if what they are saying is a fact or if it is a conclusion that is drawn from the facts. If an expert is evasive with respect to a timeline, then the attorney taking the deposition should broaden the scope of time that is being discussed and progressively narrow it. If an expert witness attempts to answer a question with uncertainty, a good technique is to ask them to rule out the opposite of what you are asking in an effort to show that the opposite of their opinion is a possibility.

Use of Depositions from Prior Cases

As mentioned earlier, the expert you are dealing with has likely testified in cases before. If so, you can do research to find the case numbers and get the transcript of the deposition from the prior case. An expert witness can always be impeached by their prior inconsistent statement under oath. Hopefully, you can find inconsistencies and use that to establish that they have no credibility.

Ask Unexpected Questions

The best part of deposing an expert is asking questions they are not prepared to answer. This can throw them off their pre-scripted answers and damage their credibility. They may attempt to argue that the questions are not relevant, but they are not allowed to make relevancy objections.

Ignore Opposing Counsel

Do not allow opposing counsel to derail you with speaking objections. All questions should be directed towards the expert, and opposing counsel can object on the record, but they cannot tell them not to answer the question because they are not the client. This means you should stay focused and ask the questions because your goal is to undermine the expert’s credibility and not to argue at length with your opposing counsel.