How to Prepare for and Depose an Opposing Party’s Expert

Knowing how to depose an expert witness is crucial for gaining insight into how to best combat the opposing party’s expert and their opinions. If done correctly, a deposition can create a strong foundation for future voir dire, evidentiary challenges, and other objections to the expert’s opinion during the trial.

Examine the Expert’s Qualifications

Before diving into their opinions, experts will likely spend time answering background questions concerning their education, training, and overall qualifications. The purpose of the questioning is to establish them as an expert in their field. This background information will likely be a part of the expert’s disclosure report. If the case is in federal court, the expert’s report, including their qualifications, must be disclosed pursuant to Rule 26(a)(2)(B) of the Federal Rules of Civil Procedure, with many states following similar procedures. However, an expert witness deposition allows you the opportunity to question the expert further. Additionally, a deposition allows you to potentially find some useful ammunition for the subsequent voir dire process.

Asking Voir Dire

A voir dire of an expert witness typically occurs during the expert’s direct examination. During this time, counsel asks questions that elicit the expert’s educational background and experience. Opposing counsel also has the opportunity to ask the witness their own questions. If you want to challenge an opposing expert’s qualifications, the voir dire is the time to do it. During the voir dire, you can also point out any credibility issues in front of the jury.

But in order to ask the right questions during voir dire, an effective expert witness deposition can help you gather information as to whether there are any ways to attack their qualifications. For example, does the expert have all of the requisite licenses and/or board certifications necessary for their profession? Even if such licenses aren’t required, does the expert have a credible reason why they aren’t licensed and/or certified? Has the expert ever had any of their licenses lapse? Are they licensed in the state in which the case is being heard? Also, most importantly, when was the last time the expert engaged in the work or practice area to which they are testifying? If there are any red flags, be sure to keep them in mind during voir dire time.

Review the Expert’s Report

Experts must disclose their findings in a written report. As such, it is important to review the report prior to the deposition of opposing expert witnesses in order to understand their opinions and the basis on which the opinions were formed. Experts must also disclose the facts or data they considered. Because of this, the report gives you a chance to question the expert’s opinion and overall methodology.

Each state has its own standard. However, most jurisdictions follow some variation of the requirements set forth in Rule 702 when admitting expert testimony. Rule 702 of the Federal Rules of Evidence establishes that the testimony must be based on sufficient facts or data. Furthermore, the testimony must be the product of reliable principles and methods, which the expert applied to the case facts. Does the opposing expert’s report make clear the facts or data on which they relied? Is the report missing key facts? What about the scientific principles or methods followed? Is the report sufficiently explanatory? Is it possible the expert relied on faulty or questionable methods? When deposing an opposing expert witness, it is essential to ask these questions to challenge the credibility of their report. Then, you can use the answers to the questions against them, if necessary, at trial.

Review the Expert’s Previous Testimony

Experts will typically disclose other cases on which they worked. If possible, review the previous trial testimony or depositions of the expert prior to conducting your own deposition. Reviewing an expert’s testimonial history might seem like an arduous task, but you do not need to do it alone. At Expert Institute, the Litigation Analytics tool offers a visual snapshot of the expert’s case history. Litigation Analytics allows you to explore critical data and pinpoint any vulnerabilities of the experts, such as credibility issues or questionable methodologies.

Familiarize Yourself with the Expert’s Industry Standards

Most experts will offer their opinions on the basis of their experiences in their practice area. Therefore, it is important to familiarize yourself with the general standards of the expert’s particular industry. By doing so, you can determine whether the expert is credibly applying their acceptable industry standard to the case. One way to do this would be to hire a non-testifying expert consultant to assist you in preparing for the deposition. This expert can help you understand certain technical or scientific issues of the case. In turn, this can help you craft appropriate questions to determine whether the opposing expert’s opinions are reliable.

Research Contradicting Opinions

As part of your own case preparation, you have likely already hired your own expert witness who may have contradicting opinions to that of the opposing party’s side. In familiarizing yourself with expert opinions that are favorable to your case, you should also identify and review any and all authoritative materials or publications that you can use to discredit the opposing expert. At Expert Institute, the Strategic Research tool has reports, compiled by medical researchers, of various peer-reviewed studies and industry journals. Do these materials contradict the opposing expert? If so, be sure to question them on it!

Lastly, make sure to check out Expert Institute’s expert due diligence solution, Expert Radar, which compiles comprehensive data on opposing experts. With 24/7 due diligence, this tool can save you lots of time with deposition preparation.

Address the Expert's Bias

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 who 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 knowing what to do when the expert gives empty answers to your questions. This could involve answers stating that the witness does not recall something, using conclusory language, or refusing to give specific answers to narrowly tailored questions. If an expert does not recall the methods they used or the basis for their opinion, this presents a major opportunity to highlight the opposing expert’s shortcomings. The attorney should then use this lack of recollection against the expert, as it undercuts the credibility of both their report and their opinion.

Other experts will attempt to answer questions in a conclusory manner to avoid discussing specifics. If this occurs, the attorney taking the deposition should not hesitate to repeatedly ask the expert witness for the basis of how they arrived at their opinions in the case. The expert should be forced to clarify whether what they are saying is a fact or a conclusion drawn from the facts.

If an expert is evasive regarding a timeline, the attorney should broaden the scope of the time being discussed and then progressively narrow it down. When 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. This approach can help demonstrate that the opposite of their opinion remains a possibility.

Managing Objections

During an expert deposition, objections are made to preserve issues for trial, with the witness still required to answer unless the objection involves privileged material or a court-ordered limitation under Federal Rule 30(c)(2). However, some attorneys may misuse objections to coach their witness, known as "speaking" objections, where they guide the expert toward a certain answer. To address this, counsel should state on the record that the behavior is improper and may result in postponing the deposition for court intervention if it continues.

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 relevant 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.