Who Qualifies as an Expert Witness?

These days it seems like everyone proclaims to be an expert in something. But when it comes to court cases, who qualifies as an expert witness?

As TV courtroom dramas show, expert witnesses are usually called in by one of the parties to help jurors understand complicated, technical concepts.

However, not everyone can qualify as an "expert," and not all types of expert testimony may be permitted. Here's a general overview:

Who Can Be an Expert Witness?

Rules about expert witnesses are set by state and federal rules of evidence, depending on whether your case is in state or federal court.

According to the Federal Rules of Evidence, a qualified expert witness is someone who has knowledge, skill, education, experience, or training in a specialized field. These qualifications are generally also required of expert witnesses in state courts.

Under federal rules, experts must base their testimony on sufficient facts or data of the type reasonably relied upon by experts in their field, in order to help the jury understand issues that typically require specialized knowledge. While non-expert witnesses can only testify about what they've seen or heard, expert witnesses are generally allowed to give their specialized or professional opinion.

States have similar rules, though there are notable differences among states when it comes to the admissibility of expert testimony.

Admissibility of Scientific Testimony

One issue that often arises with expert witnesses is whether scientific testimony will be allowed in court.

For scientific issues that aren't seriously disputed, judges may take judicial notice. This means that the judge accepts the testimony as fact because it's something a person of average intelligence already knows.

For more controversial scientific issues, courts must determine if the testing methods were reliable before admitting the expert's testimony. In federal courts and in many states, judges will ask whether the scientific issue in question has been subjected to peer review, whether it can be tested, and whether the procedures have been published. Courts will also look at the rate of error in the testing.

In a few other states, the test used by courts is slightly different: The reliability of the scientific evidence must be acknowledged by the scientific community in order to be admitted. The expert must be qualified to conduct the testing and provide proof that correct procedures were followed.

As you can see, the rules regarding expert witnesses can get complicated. For more guidance on using expert witnesses in your particular case, consider consulting an experienced litigation attorney near you.

Related Resources:

• Can I Be an Expert Witness? (Slate)
• What Counts as Witness Intimidation? (FindLaw's Blotter)
• When Should Attorneys Hire Expert Witnesses? (FindLaw's Strategist)
• What is the Role of a Jury in a Criminal Case? (FindLaw)