7 Keys To Effective Direct Examination of Expert Witnesses


Direct Examination of Expert WitnessesWhile the cross examination of a witness is often viewed as a climatic moment in a trial, the direct examination of a witness, particularly an expert, can be of equal, if not greater importance to the outcome of a case. Knowing how to effectively conduct a direct examination of an expert witness can set the tone for the entire trial. The following are seven helpful tips to ensure that your direct examination is a success.

1.Choose an Expert: The Earlier the Better

Once it is decided that an expert witness will testify at trial, finding the most qualified, experienced, and professional expert should be prioritized. By definition, experts are brought into a case because their knowledge and skillset can assist the trier of fact in ways that lay witness testimony cannot. As enumerated in Rule 702 of the Federal Rules of Evidence, experts are to use their “scientific, technical, or other specialized knowledge” to help the trier of fact in understanding the evidence or determining a fact in issue.

Expert testimony must also be based on sufficient facts and reliable principles and methods. Because experts are versed in knowledge that is most likely foreign to the jury, it is critical to spend as much time as possible with your expert prior to trial. The crucial trial preparation stage will be less arduous if the expert has already been a part of the litigation team since the inception of the case. A quality direct examination can be just as difficult to craft as a cross examination. So the more time the attorney and expert have to prepare, the more effective the testimony will be.

While it is obviously necessary to hire an expert who possesses the requisite level of expertise in its particular field, it is also important to examine the expert’s demeanor. Oftentimes, juries assess credibility by the witness’ behavioral patterns, expressions, and voice. Therefore, it is important to hire an expert as soon as possible so his presentation can be assessed.

2. Adequately Present the Expert’s Qualifications

Typically, direct examination begins by establishing the expert’s qualifications. The first few questions about the expert’s professional background should demonstrate to the judge that the expert possesses the requisite qualifications to testify; while also showing the jury that the expert is capable of rendering accurate opinions. Depending on the practice area, an expert may testify as to formal education, work background, on-the-job training, or other credentials. It is helpful if an expert has both academic and practical experience. It provides a more well-rounded picture of the expert’s background. While not a necessary tactic, it can be beneficial to humanize the expert on direct examination by asking questions that help the expert appear three-dimensional to the jury. Tying in anecdotes about the expert, or mentioning her hobbies during the introductory questions may increase the chance that the expert will be viewed as someone relatable, and by extension, trustworthy.

3. Use Everyday Language When Explaining Complex Ideas

The main purpose of an expert is to help the jury better understand the facts at issue by explaining technical information in an easily digestible format. To help your expert achieve this goal, the direct examination must comprehensively flush out any complex or confusing testimony. It does not matter whether an expert is the most qualified in her field or if she presents indisputable opinions.

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If a jury does not understand the testimony, it will be of little use. Avoid legalese or scientific terminology by substituting those words or phrases with everyday language. When explaining a complex procedure, the expert should analogize each step with something that is easier for non-technical jurors to understand. For example, a medical expert testifying about heart surgery can analogize the unblocking of a clogged artery to the opening of a lane during a traffic jam. The goal is to ensure that the jury fully understands the expert. And that they are able to apply the testimony to their own decisions when rendering a verdict.

4. Elicit Testimony Within the Expert’s Scope

While it can be tempting to question an expert on a broad range of matters, it is important to stay within the constraints of the governing rules of evidence. In federal courts (and state courts that have adopted such evidentiary rules), expert testimony must be both reliable and relevant. Likewise, an expert may base an opinion on facts or data that the expert has been made aware of. Or that he has personally observed.  An expert need not disclose all facts and data on which the direct testimony relies. However, the witness may be questioned about those facts on cross examination. If an expert’s opinion is based on questionable data or unreliable methodology, such weaknesses can be exposed on cross examination. Therefore, the direct examination should be as forthright as possible in order to defend against adversarial surprise attacks.

5. Utilize Demonstrative Evidence to Illustrate the Testimony

Demonstrative evidence is evidence addressed directly to the senses without the intervention of testimony. It can be presented in a variety of forms such as photographs, diagrams, models, illustrations, audio recordings, or in-court experiments. Demonstrative evidence impresses a jury’s senses, and thus, provides an additional means of evaluating the facts of the case.  The main purpose of demonstrative aids is to help the jury more fully understand the factual issues; while also breaking the monotony of oral testimony. The specific type of demonstrative aid used is dependent upon the particular expert testimony. However, incorporating such evidence can benefit both the style and substance of the direct examination.

6. Address Any Credibility Issues Up Front

No direct examination or expert witness is perfect. Addressing any credibility issues at the onset of direct examination can be beneficial in two ways. First, by questioning the expert on any perceived weaknesses, it takes the sting out of the cross examination. It also precludes opposing counsel from appearing to have “caught” the expert in a lie or misrepresentation. Secondly, it shows the jury that the expert is honest, which in many cases, can bolster the expert’s credibility.

During cross examination, opposing counsel will often ask an expert’s fees, in order to show that the fees are exorbitant in relation to the expert’s work. To preemptively defend against such a point, a direct examination can include a brief line of questioning about the time and effort the expert put into the case. For example, the expert can cite the materials reviewed and experiments conducted and give an estimate of the time expended. In addition, an expert may have put other professional commitments on hold to prepare for the trial.  The goal is to establish the expert as a credible professional who is fairly compensated for his work.

7. Conclude the Testimony By Summarizing the Case Theory

Ideally, the case theory should intertwine with all aspects of the trial. The direct examination may begin with more scientific, complex ideas, but once the expert thoroughly explains and breaks down his opinions, the testimony should ultimately mirror the attorney’s case theory as told in an opening statement or summation. Experts should be able to reiterate the case theory, while also maintaining their own voice. If a direct examination is successful in helping the jury understand the scientific or technical facts of the case, then the jury should be able to apply those facts when deciding the ultimate issue. By summarizing the testimony at the conclusion of the direct examination, the expert is showing the jury a new point of view while still emphasizing the theory of the case.

About The Author

Anjelica Cappellino, J.D. is an accomplished defense attorney and legal writer who has represented numerous federal criminal defendants in the Southern and Eastern Districts of New York.

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