§ 24.05 Qualifications Requirement

• Jurisdiction: United States

§ 24.05 Qualifications Requirement

If the subject matter is a proper one for expert testimony, the next question is whether the proffered witness is qualified in that subject matter. Rule 702 provides that a witness may be qualified as an expert by "knowledge, skill, experience, training, or education."¹¹⁹The trial judge determines this issue pursuant to Rule 104(a).¹²⁰

The party offering a witness as an expert carries the burden of establishing that the witness is qualified. There are some rules-of-thumb. For example, the expert need not be the best witness on the subject, nor "an outstanding practitioner in the field in which he professes expertise."¹²¹ The expert generally need not be licensed, although this factor is relevant to the qualification issue. Similarly, certification in a particular field may indicate that an expert's opinion is entitled to greater weight, but certification is not a prerequisite to qualification as an expert witness.¹²² Nor must the expert's qualifications match those of the opposing side's experts.¹²³ Furthermore, the expert's qualifications should be based on the nature and extent of the witness's knowledge and not on the witness's "title."¹²⁴

Practical experience. Experience alone may qualify a witness to express an opinion. There is no "degree" requirement, per se.¹²⁵ Wigmore stated the matter this way: The witness's expertise "may have been attained, so far as legal rules go, in any way whatever; all the law requires is that it should have been attained."¹²⁶ For example, a woodworker with 36 years experience could testify about the construction of chairs.¹²⁷ One case even involved an experienced "marijuana smoker."¹²⁸

Testimony beyond expertise. An expert qualified in one subject may not be qualified in another (even a related) subject.¹²⁹ For example, a police officer may be qualified to operate a breathalyzer but not qualified to interpret its results. The training and experience needed to perform these two distinct functions are very different.¹³⁰ Similarly, a police officer may be qualified to conduct a horizontal gaze nystagmus test (an intoxication test) but not be qualified to interpret the results.¹³¹ In other words, there is a difference between a scientist and a technician.

Hired gun. In civil litigation, the "hired gun" phenomenon arises. Some experts spend more time testifying than practicing in their field.¹³²

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Notes:

^[119] See Fed. R. Evid. 702 advisory committee's note ("The expert is viewed, not...