An expert witness is used when scientific, technical or specialized testimony will help the jury understand the evidence or resolve a disputed issue.  

What Qualifications Do Expert Witnesses Need?

The Federal Rules of Evidence do not specify any specific qualifications for an expert witness. However, the judge should be persuaded that the expert witness has special technical or specialized knowledge that lay people do not have. This special knowledge can be a result of the expert’s education, professional experience or specialized training. The judge tries to ensure that the testimony given from any expert witness will be reliable and helpful.

Is Evidence given by an Expert Always Admissible?

No. The judge has the discretion to determine that the evidence given by an expert is not reliable and so should not be admitted. The judge uses the following factors as a guide to determine if evidence given by an expert witness should be admitted or excluded:

  • Is the evidence helpful to the judge or jury?
  • Is the witness qualified?
  • Is the testimony based on sufficient facts or data?
  • Is the testimony a product of reliable methods or principles?
  • Did the expert apply the facts of the case reliably?

The judge can also exclude evidence that would confuse the jury, unfairly prejudice a particular party or would be too time consuming to present to the jury.

How to Choose an Expert Witness

There are many issues to take into consideration when deciding whether or not to use expert witnesses. Below are a number of considerations to take into account when deciding whether or not to use an expert witness:

  • Is the expert a professor or other professional who can explain difficult concepts clearly?
  • Can the expert make a persuasive delivery to the jury?
  • Does your expert have the time to prepare for a case?
  • Would it be easy for opposing counsel to show that your expert is biased or is not independent from your case?

Do Expert Witnesses Always Testify?

No. An expert may simply be best suited to help you evaluate a case by surveying the portion of a case. For example, if a company manufactured a machine that exploded, a fire and explosion expert may be helpful in determining if that explosion was the result of a manufacturing defect. This expert’s report will not be given to the other party in discovery and the expert will not have to testify.

Do I Need to Talk to an Attorney about Expert Witnesses?

If you feel you have a case where an expert witness will be required, you should consult an experienced attorney. The trial process is incredibly complicated, but the right expert witness can be a tremendous advantage to your case. An attorney will also know how to ensure that your non-testifying expert remains protected from discovery so that the information gathered by this expert will not be shared with the opposing party.