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Presenting Expert Trial Testimony



A. When to Call the Expert?

After an intense selection process, preparation of the expert and discovery, experts must ultimately perform well at trial to justify their expense.


If the expert intends to base his opinions on the testimony of other witnesses, his testimony must naturally follow those individuals. Otherwise, the expert's position in the "line-up" depends on a host of strategic considerations unique to the case at hand. In some cases, expert witnesses are the first witnesses called where the proponent wishes to emphasize the expert's testimony and put her best foot forward. This strategy is often pursued in personal injury cases, where the plaintiff calls the treating physician as the first witness to place great emphasis on damages while de-emphasizing liability issues.

Sometimes, the strategy is dictated by the expert's own availability for live testimony or by the time of day in which the expert would otherwise be called to the stand. Because expert testimony often involves more technical subject matter, it is more advantageous to call your expert when the jury is most alert and attentive. Regardless of the power of an expert presentation, experts called late in the afternoon when the jury has grown restless through a full day of testimony may get lost amidst the yawns of jurors. Despite hours of preparation, the precise timing of testimony is an important factor in determining its effectiveness. To the extent that an attorney can exercise any control over scheduling, he or she should schedule the expert for maximum effectiveness.

B. Qualifying the Expert

At trial, one must demonstrate the expert's superior qualifications in a manner that will impress the jury with his credibility rather than with his immodest portrayal of perfection. When presenting the "oral resume," many attorneys make the mistake of coaching the expert to boast of major achievements, awards and degrees. Rather than enhance credibility, such boasting only creates resentment among jurors who frequently lack the same professional achievements.

To minimize the risk of resentment and develop a rapport with jurors, expert witnesses should demonstrate some degree of modesty on the witness stand. For example, in questioning an expert on her academic background, the expert may initially respond that she "received [her] M.D. in 1980." In response, the attorney may then ask a leading question eliciting the fact that the expert not only graduated, but graduated at the top of her class at The Johns Hopkins University School of Medicine, receiving a prestigious fellowship in orthopedic medicine. In a subtle way, the attorney may preface this question by cautioning her not to be so modest in minimizing impressive accomplishments. With such encouragement, the jury will perceive that the detailed recitation of credentials do not reflect the expert's immodest desire to exhibit accomplishments, but rather a need to communicate this expertise for the jury's consideration.

When presenting the expert's credentials, it is important to be thorough. Although a small recitation of accomplishments may be sufficient for the court to accept the witness' qualifications and bestow the title of "expert," this will not maximize credibility in the jurors' minds. Thus, even where opposing counsel offers to stipulate to the witness' expertise, that invitation should be politely declined in an effort to impress the jury with the full extent of these qualifications.

After presenting the expert's credentials in all of their splendor, the attorney calling this witness should make eye contact with the judge and jury while proudly offering the witness as an expert in the relevant field. If this proffer is challenged on voir dire, the expert should view this as an opportunity to truly demonstrate expertise by maintaining an even demeanor and politely responding to the attack. Thereafter, the attorney calling the expert may wish to elicit an additional, stunning credential as the finishing touch in qualifying the witness.

C. Direct Examination: Bolstering Expert Credibility

1. Questioning Strategy

Provided that you have selected an effective communicator as your expert witness, the direct examination should provide the witness the opportunity to shine on her own. Rather than clutter the record with long-winded questions, the attorney should merely facilitate and guide the expert's explanation and analysis of the case. Because the expert is teaching the students in the jury box, the attorney should also adopt the role of an interested student and must not obstruct his expert's presentation.

Questions should be very brief and very simple. With proper planning, the expert will know the areas of inquiry and respond appropriately. Questions should highlight important areas of testimony. To make the best use of the jury's attention, the attorney should first ask the expert to provide her opinion and only then ask the expert to provide the more lengthy explanation.

In many cases, one may effectively summarize the evidence for both the expert and the jury in the form of a hypothetical question. These questions may be very effective if they mirror facts which are easily provable and have been presented in evidence, hit the fundamental points of your case, and do so briefly. The long-winded hypothetical question will prompt numerous objections, bore the jury to tears, confuse the evidence and -- even worse -- prompt the expert to ask that the question be repeated! Keep it short and sweet and, hopefully, the jury's deliberations will be as well.

2. Simplifying the Presentation

Despite misapprehensions to the contrary, an expert's role is not to fill the courtroom with erudition. The expert's role is to eliminate confusion by simplifying complexities into neat packages which jurors can understand and relate to. Even the most complex medical testimony can be simplified through the use of analogies which we may all comprehend. For example, in explaining a herniated or ruptured disc, an orthopedic surgeon may analogize it to the squeezing of a jelly donut. The donut punctures and the jelly escapes. We can all relate to the mess that is created afterward!

Simple analogies and simple language are the hallmark of effective expert testimony. Shorten explanations to spare the jury all of the confusing terminology, concepts and background information which you had to wade through in preparing for trial. If you do, the jury will reward this consideration with greater attentiveness and, perhaps, a favorable verdict.

3. Avoiding Boredom

During expert testimony, make every effort to keep the jury from snoring. A sleeping jury will not catch the compelling testimony your expert will provide. After establishing rapport with the jury during the qualification stage, the expert should maintain eye contact with the jury and, in appropriate circumstances, add a touch of humor or personality to the presentation. One method of adding to the interest of a presentation is through the use of demonstrative evidence.

4. Demonstrative Evidence

Show 'n' Tell kept all of us awake as school children. The same principle can be used to keep the jury awake in the courtroom and to create memorable impressions of the evidence.

Regardless of the quality of your expert, few expert witnesses can capture the jury's attention without models, diagrams, audio or video recordings, charts or photographs as an aid to understanding. Like any effective classroom presentation, expert testimony is far more powerful when the expert can show the jury exactly what he means and appeal to more of their five senses. Indeed, effective use of the blackboard can add life to an otherwise dull expert presentation. The use of demonstrative evidence also allows the expert to get physically closer to the jury by approaching easels positioned next to the jury box or by holding models or photographs in front of jurors so that they can see precisely what he means.

When conducting your direct examination of the expert, organize the presentation to allow for at least one diagram, object, or other type of demonstrative evidence for every ten to fifteen minutes. With each visual demonstration, you will renew the jury's interest and attention, reduce boredom, and keep jurors awake long enough to learn from your most crucial witness.

D. Cross Examination: The True Test of Expertise

Although direct examination should allow your expert a full opportunity to explain the case in a light most favorable to your client, cross-examination is his best opportunity to score points with the jury. After a successful presentation on direct examination, jurors inclined to believe the expert wait patiently for the roof to cave in above him on cross-examination. If it does not, and the expert has escaped unscathed, his mission with the jury is accomplished. Otherwise, he may limp away from the witness stand having unwittingly done considerable damage to the party calling him.

In preparing your expert for cross-examination, you should thoroughly grill your expert with numerous, hard-hitting cross-examination questions designed to attack every aspect of his testimony and impeach his credibility. Encourage your expert to pause before answering each question, reflect carefully on the scope of each question and -- after counting to three -- answer the precise question asked in a calm, deliberative manner. Even where the jury does not understand the substance of testimony or the precise points being made on cross-examination, they pay very close attention to the expert's demeanor in assessing his credibility. By controlling emotions effectively, even experts who have fallen prey to substantive traps may emerge from the process looking untouched by attempts to impeach credibility.

1. Effective Impeachment Strategies

If you are cross-examining the expert, the difficulty of your task depends upon the strength of the opposing expert. While you may score points at many levels with a variety of techniques, the stellar expert is always difficult to attack. Thus, in some cases, your goal in cross-examination may be to make a few key points and get the witness off of the stand quickly.

In other cases, cross-examine the expert in the following ways:

a. Emphasize the favorable aspects of her testimony - even where the expert renders an unfavorable opinion on the bases of certain factual assumptions, you may be able to elicit more favorable testimony by modifying the facts to conform more closely to your theory of the case. Moreover, where an expert renders an unfavorable opinion on certain liability issues, she may be helpful in substantiating damages and, in that capacity, actually become your witness.

b. Impeach the field of expertise - provided that you do not call an expert from the same field, you may be able to attack the legitimacy of his profession. This has been attempted, with varying degrees of success, in impeaching chiropractors, handwriting analysts and a host of other experts which the court has nonetheless accepted as witnesses. Assuming that the court is unlikely to deny your opponent's proffer of the expert, such an attack may be more effective on cross-examination than on voir dire.

c. Impeach the expert's qualifications - unless your opponent calls the latest Nobel prize-winner, there is normally some room for emphasizing gaps in education or relevant experience. However, you should not overstate this attack against experts who are clearly qualified to testify. Indeed, such an impeachment strategy may backfire with eminent experts.

d. Impeach the expert's bases for the opinion - if the expert has based his opinions on inaccurate or incomplete facts, or has failed to conduct a thorough investigation, the opinion will look similarly incomplete or inaccurate.

e. Change the facts - if you have a reasonable basis for modifying the facts, determine whether the expert's opinions will change for the better.

f. Impeach with a learned treatise - does the expert's view comport with the relevant scholarship on the subject?

g. Impeach the expert with prior inconsistent statements, or ill-conceived statements, in his own reports, depositions, or prior publications. After obtaining the expert's curriculum vitae in discovery, review pertinent articles for material which you may use on cross-examination. Closely scrutinize the expert's deposition in your case and his reports on the matter at hand. In fact, you may even want to seek transcripts of other depositions or trials in which the expert has testified. In personal injury cases, the Maryland Trial Lawyers Association and similar groups actually maintain a library of expert deposition transcripts donated by member attorneys to provide a resource to members wishing to impeach experts called against them. Such material, if useful for impeachment, may yield very damaging and discrediting information.

h. Impeach the expert's credibility on the basis of bias or other motives to render certain opinions - an expert witness is, at bottom, still a witness and is subject to the same types of credibility attacks as others who dare to take the witness stand.

While total destruction of the expert may be a worthy goal, do not let this objective show by the manner in which you conduct the cross-examination. Belligerent attacks and similarly obvious impeachment techniques are far too elementary to trap a sophisticated witness, much less an expert in his field. By patiently attacking the bases for testimony, one may ultimately succeed in undermining the core of the expert's analysis. Even if you do not achieve destruction, take satisfaction in the ability to score important points to deflate the expert's air of infallibility and ego.

E. Re-Direct Examination: Getting the Last Word

Very few experts escape totally unscathed on cross-examination. Re-direct examination provides the opportunity to rehabilitate your witness in the face of such attacks. It also provides the last word on the subject. As such, re-direct examination is an opportunity that should not easily be waived. However, it should be relatively brief, focusing on key points which you want to register with the jury.


While expert testimony presents unique challenges in trial preparation and presentation, it provides special opportunities to strengthen your case which should always be considered in developing strategy. When undertaking any type of litigation, consider the potential for expert consultation and testimony. By effectively using experts in a variety of cases, you may gain a greater understanding of your own case and present in the form of testimony what could, at most, only have been alluded to as arguments on cross-examination. In most cases where experts compete for the jury's understanding and attention, winning the battle-of-the-experts will ultimately win the war being waged at trial.


The Maryland legal information provided on Maryland evidence law, expert witness qualifications, qualifying an expert, scientific evidence, examining an expert at trial, cross-examining expert witnesses, re-direct examination, grounds for expert testimony, admissible opinion testimony, expert discovery, objections to testimony, objecting to witness opinion, taking the stand, medical experts, engineers, forensic accountants, professional witnesses, conducting depositions of experts, conducting discovery of expert opinions and Maryland rules of evidence on expert opinion and testimony is designed for informational purposes only and is not intended to constitute legal advice. The slogans, High-Speed Access to Legal Action, Legal Advice, Legal Counsel, Legal Protection, State & Federal Courts, Dispute & Conflict Resolution, Probate Protection, Legal News, Legal Training & Seminars, and the substantial equivalent thereof are service marks of Kramer & Connolly.