The Art of Cross-Examining Expert Witnesses

July 09, 2024
Mastering the art of cross-examining expert witnesses takes time and practice, but with careful preparation and strategic execution, you can effectively challenge the testimony of even the most seasoned experts.

The Art of Cross-Examining Expert Witnesses

Jay V. Prabhu, Esq., Managing Director, ExpertConnect Litigation Support LLC.

Cross-examining an expert witness is often a critical moment in litigation. It’s an opportunity to challenge the credibility of the witness, undermine their conclusions, and ultimately strengthen your case. However, it requires careful preparation and strategic execution. In my more than 25 years of legal experience, here are some lessons that I have learned.

1. Know Your Case Inside and Out

Lawyers must completely understand their cases. This statement may sound trite but, far too often, lawyers don’t fully comprehend the impact of a certain line of questioning, a potential concession, or an unexpected answer. You simply need to know the facts, the legal issues, and your theory of the case long before you are putting together cross-examination questions, questioning an expert in a deposition, or standing at a podium. I had the luxury of working for both a top Washington, D.C. law firm and the federal government where you had the freedom to run down any possible issue. Not every situation allows for this, but it is obviously the best practice.

2. Understand the Expert’s Testimony

Take the time to thoroughly review the expert’s report, deposition testimony, and any other materials provided. Understand their methodology, assumptions, and the basis for their opinions.  Work closely with your client or your own experts to figure out what the expert witness is likely to say and why. This will allow you to craft targeted questions that more effectively challenge their conclusions.

3. Identify Weaknesses and Inconsistencies

Look for weaknesses or inconsistencies in the expert’s testimony. Always examine any previous testimony and focus particularly where their opinion was rejected or undermined. Past cross-examinations can also provide you a roadmap with which to start. Key findings would be errors in their analyses, contradictory statements, or biases that may affect their opinions. Use this information to impeach the witness and undermine their credibility.

4. Prepare Your Cross-Examination Outline and Annotate it During Direct

Create a detailed outline of the points you want to cover during cross-examination, with additional notes, especially quotes, added from direct. Organize your questions logically and anticipate potential objections or responses from the witness. This will help you stay focused and effectively control the examination.  Do not, however, get locked into your outline and forget to listen actively.

5. Use Leading Questions

Cross-examination is not the time for open-ended questions. Use leading questions that suggest the answer you want to elicit. This will allow you to control the direction of the examination and prevent the witness from going off-script.  “Yes” is a great answer from a witness, especially if it is in a series of affirmative responses that locks in the witness.

6. Actively Listen to the Witness’s Answers

Pay close attention to the expert’s responses during cross-examination. Listen for inconsistencies, evasions, or admissions that support your case. Be prepared to follow up with additional questions to exploit any weaknesses you uncover.  Above all else, do not get locked into your prepared questions and miss these opportunities.

7. Maintain Control and Stay Calm

Cross-examining an expert witness can be intense, but it’s important to remain calm and composed. Avoid getting drawn into arguments or becoming overly aggressive. Expert witnesses are usually experienced professionals, who are chosen for their ability to come across well to the trier of fact. You must focus on asking clear, concise questions that advance your case, and preventing the expert from using cross-examination to score additional points for their side. By being forceful, but reasonable, you are far more likely to get under their skin and get them to undermine their testimony.

8. The Big Question in Cases of Asymmetric Parties

There is one question that I almost always ask at the end of cross-examination. It is particularly effective in a criminal matter or when your side is not putting on a counter-witness. “How much were you paid for your testimony today?” Smart experts will respond that they are paid for their time, and not their opinion or testimony, but often you can use a spontaneous answer of just an amount to suggest bias. Juries are often shocked by how much expert witnesses are paid and it can really color the weight they give an opinion. This tip, admittedly, is not as helpful when there is a battle of expert opinions since both sides will likely have significant witness costs, but it is an arrow to keep in your quiver where appropriate.

Mastering the art of cross-examining expert witnesses takes time and practice, but with careful preparation and strategic execution, you can effectively challenge the testimony of even the most seasoned experts.