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Law 101: Legal Guide for the Forensic Expert

Important Traits That Enhance Expert Witness Credibility

Extensive observation of expert witness testimony in numerous actual trial settings generates a series of positive traits that can guide the expert in achieving testimonial excellence:

  • Knowledge of the specialty area.
  • Ability to translate the complex into the simple.
  • Open-handed honesty, even to the extent of admitting fallibility or possibility of error.
  • Substantial history of solving similar problems in the past, both actual and theoretical.
  • Testimony consistent with that of other experts.
  • Use of expert information and investigation in unique ways.
  • Creative preparation of models, charts, drawings and demonstrations.
  • Irrefutable scientific, technical, factual or professional data back-up.
  • Careful attention to factual elements, measurements and similar components.
  • Supportive use of the literature.
  • Absence of exaggeration or underestimation.
  • Careful testing and documentation.
  • Ability to support every conclusion with an example and real-life application.
  • Correct use of standard formulas.
  • Coordination of verbal testimony with documentary and demonstrative evidence.
  • Quiet, calm and humble demeanor, combined with self-confidence and conviction.           
  • Opinions that are supported by the admitted evidence.
  • Use of opposition testimony to support the expert's own position.
  • Ability to combine facts and substantive factors to yield a meaningful result.
  • Hands-on participation in a corrective process.
  • An outstanding résumé.

A number of important factors help the testifying expert establish credibility:

  • Believability.
  • Integrity.
  • Respectful treatment.
  • Expertise.
  • Credentials.
  • Ability.
  • Experience.
  • Honesty.
  • Sincerity.
  • Truthfulness.
  • Ability to demonstrate and convince.
  • Effective preparation and presentation.
  • Ability to be neutral, objective and open.
  • Consistency in performance.
  • Being knowledgeable.
  • Up-to-date information.
  • Professional practice and diligence.

There are several useful ways to present and enhance these factors, including:

  • Establishing the main points early in testimony.
  • Recognizing the need for common-sense explanations.
  • Repeating key points.
  • Having positive and open body language.
  • Repeating the main points at the conclusion of testimony.

Testifying experts have found several admonitions most useful in their testimonial experience:

  • Answer only the question asked, and do not volunteer information.
  • Be factual, truthful and concrete.
  • Stick to the point and be brief.
  • Do not argue with counsel, the court or the tribunal.
  • Keep calm and never display irritation.

The essence of trial competence centers on the expert's ability to project an image of credibility from beginning to end. This requires:

  • Accurate citation.
  • Precise factual presentation.
  • Articulate organization of graphic materials.
  • An organized presentation of testimony and documentary evidence.

As part of the expert's credibility effort, the expert must project an attitude of honesty, integrity and believability. Given the fact that both sides in a dispute tend to present their own conflicting views, the expert must serve as a beacon of believability. In this context, "expertness" is the extent to which the witness appears to be:

  • Competent.
  • Intelligent.
  • Authoritative.
  • Well-trained.
  • Experienced.
  • Skilled.
  • Informed.
  • Professional.
  • A source of valid information.

Additional traits that are beneficial to the expert witness include being:

  • Honest.
  • Open-minded.
  • Friendly.
  • Well-mannered.
  • Warm.
  • Fair.
  • Polite.
  • Dynamic.
  • Positive.

These factors, traits, characteristics and techniques can be readily projected in the testimonial process, which is initially displayed on direct examination. The expert can:

  • Convey the fact that the forensic witness is a professional who is dedicated to accurate and detailed work.
  • Avoid any impression that the testifying expert is a "hired gun" by not being drawn into biased or exaggerated statements.
  • Emphasize the specialized task(s) performed in the case, and that testimony represents professional investigation and careful analysis.
  • Be ready to bolster opinions with recognized technical publications.
  • Not be afraid to expose the weakness of the case to counsel.
  • Project oneself as a reliable source of information.
  • Be a good listener.

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Date Created: August 7, 2023