What does an Expert Witness Needs to Know About Court Proceedings? Here are some thoughts to keep you expert out of the rough:

 
1. Review all evidentiary foundations. You should review the appropriate
foundational requirements for the admission of any records, tests, or other analysis which is not
stipulated to by the opposing party. Remember under Rule of Evidence 703, your expert can
consider matters outside the evidentiary record at trial in reaching his opinion.  

2. Standard of proof or level of confidence required. This distinction has
somewhat dissipated. However, a number of judges still require the use of the “magic words.”
Typically, at the beginning, it makes sense to ask that your expert give his opinion in the case
based upon a reasonable degree of medical or scientific probability unless instructed otherwise.
Caution your expert to avoid using the phrase “possible” since it is legally meaningless.  

 
3. Reliance on materials outside of the court record. The facts or data in the
particular case upon which an expert bases an opinion or inference may be those perceived by or
made known to the expert at or before the hearing. Experts may testify to opinions based on
inadmissible evidence, provided that it is of the type reasonably relied upon by experts in the
field. Federal Rule of Evidence 703. Typically, I would ask the expert ‘If in reaching his  opinions and conclusions in this case, did he use only materials reasonably relied upon by  persons in his field? 

4. Role as an educator/not an advocate. KISS—Keep it simple, stupid! Avoid
technical terms. Use models or diagrams whenever possible. Above all, make it interesting!  The expert should be enlightening, not boring! In this regard, less is more. Get to the point early. The expert needs to be an educator, not an advocate. That’s your job.  

5. Professional demeanor. Make sure your expert has the knowledge and control
to avoiding taking the bait! No matter how the opposing attorney acts, your expert must stay
polite and professional. Avoid sarcasm or insults. Credibility will ultimately be lost.  

6. Review of demonstrative evidence. If you are going to use charts, models or
diagrams, make sure they are properly disclosed in advance, and if possible included with your
expert’s report. Likewise, summaries under Rule 1006 need to be produced in advance.  

7. In court demonstrations or “experiments”. Make sure you practice them and
they will definitely work. You don’t want to hear, “If it doesn’t fit, you must acquit.”

8. Review prior materials for any mistakes or errors. Look one last time for
problems. Deal with any mistakes or error on direct, and deal with any shortcomings honestly.
You will gain credibility and avoid the sting of these topics on cross-examination.  

9. Absent Subpoena Duces Tecum, limit materials brought to court. Bring only
those items which have previously been produced. Be ready to answer questions regarding
compensation paid, and hours of work spent. Remind your expert that he is paid for his time, not
his opinion.  

10. Contrast and compare expert’s qualifications with those of any opposing
expert. Show what he brings to the table that the other expert is missing, whether it is in the way
of experience, time spent, or knowledge. Show the jury why your expert is the better guide.  

11. Cover adequacy of facts included in any hypothetical questions. If you plan
or may ask a hypothetical question, make sure you review the relevant factors in advance of trial
with your expert so you are both on the same page. Write out your question so you are
consistent in the way you ask it.  

12. Likely tactics of opposing counsel. Know your opponent. In the seminal book, “
The Art of War” Sun Tzu advises:

“If you know the enemy and know yourself, you need not fear the
result of a hundred battles. If you know yourself but not the enemy,  for every victory gained you will also suffer a defeat. If you know  neither the enemy nor yourself, you will succumb in every battle.”  

Ask around and learn your opponent as well as yourself and your own case, and you, too, will
have nothing to fear.