Why are Expert Witnesses Important in Personal Injury Cases?


Personal Injury

Importance of Expert Witnesses

Expert witnesses are essential in many personal injury cases.  When an issue or dispute is considered too complex for the ordinary juror to understand without the assistance of an expert, Illinois law requires that an expert witness be called to explain the complexities and provide opinions to the jury. If the plaintiff doesn’t call an expert witness to testify regarding such issues, then the court will generally not permit the plaintiff from placing such issues before the jury.  If the issue is essential to winning the case and plaintiff doesn’t call an expert, then the case will be lost.

Expert testimonies usually occurs in cases involving:

  • Physics
  • Engineering
  • Statistics
  • Violation of standards
  • Violations of safety rules
  • Violations of custom and practice
  • Permanent injury
  • Causation
  • Issues pertaining of standard of care in medical or legal malpractice cases

The most common use of an expert in a personal injury case is probably the treating physician.  He is needed to place the issue of permanent disability and causation before the jury.  For example, to prove that a plaintiff has a permanent back injury and that it was caused by the accident in question, the plaintiff’ attorney needs to call either a treating physician or a hired expert to testify that the injury is permanent and caused by the accident.   Since the ordinary juror is not a physician, jurors are generally not permitted to evaluate such issues with the aid of an explanation from an expert witness.  If the plaintiff’s attorney fails to call the expert to testify, plaintiff will be unlikely to recover for any permanent injury and the jury will not be permitted to decide that issue. Hence, in most personal injury cases, a treating physician or hired expert must be called to testify.   The more complex the case, the more experts will generally be called.  However, as with most rules, there are exceptions that have to be evaluated on a case by case basis.  If you remember this basic rule, you will know if an expert is needed in a case: “Is the testimony beyond the understanding of the ordinary juror”.  If the answer is yes, an expert is needed.
If you have questions, please contact our office and speak with one of our experienced personal injury lawyers:

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