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Law 101: Legal Guide for the Forensic Expert

Testimony Tips From Trial Judges

Trial judges are an excellent source for tips and constructive suggestions for testifying experts. They have presided over many cases involving testifying experts, and they have a unique sense of what mannerisms, abilities and traits work in court — and which ones don't work.

Following are some useful testimony tips and suggestions for testifying experts from trial judges:

  1.   Always tell the truth, even if it hurts.
  2.   Do not be pompous or egotistical.
  3.   Do not speak down to the fact finders.
  4.   Use plain English — translate technical terms when necessary.
  5.   Do not be an advocate for the case — be a knowledgeable expert.
  6.   Do not evade cross-examination questions.
  7.   Do not volunteer extraneous information.
  8.   Do not be a show-off.
  9.   Be aware of court procedure and practice.
  10.   Do not be a know-it-all about how the case should progress.
  11.   Do not testify above the heads of the courtroom personnel.
  12.   Be lively and vibrant, not boring.
  13.   Do not stray beyond your area of expertise.
  14.   Do not feel you need to have an opinion on everything.
  15.   Answer the question that is asked and then stop talking.
  16.   State why you cannot answer the question.
  17.   Tip off the calling attorney to come back to an area of cross-examination ("Yes, but may I explain?").
  18.   Correct mistakes at once.
  19.   Do not try to defend a wrong answer.
  20.   Do not cause the judge to admonish you for any reason.
  21.   Do not keep repeating the same points over and over.
  22.   Keep your reputation impeccable.
  23.   Always maintain credibility.

In addition, a veteran trial judge suggests:

  1.   When qualifications are presented, use only the highlights of a professional career and not every minute detail.
  2.   Make sure expert opinions are based on a reasonable degree of technical, scientific or professional probability.
  3.   Be prepared to explain the "why and wherefore" of expert conclusions.
  4.   Don't be afraid to undertake a practice session of direct and cross-examination before offering testimony. The expert's poise may increase dramatically as a result of practicing responses and delivery.
  5.   Expose any weak areas of the case during direct examination, such as frequency of testimony for a particular side, length of examinations, retention by opposing counsel, payment for testimony, and possible disagreement with opinions of other experts.
  6.   Translate all testimony into nontechnical terms — words that can be understood by everyone in the courtroom.

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Date Created: September 1, 2023