Why Do Expert Witnesses Matter?

by | Dec 31, 2015

Attorneys often emphasize the importance of having strong expert witnesses, whether the witness is testifying in a criminal case, a division of marital assets in a divorce, a contract dispute over unpaid employee wages, or any other legal matter. Having an attorney who has a strong understanding of the rules governing expert witnesses is an invaluable asset in a client’s arsenal. Durham-based attorney Mark Hayes continues to show strength in this area.

One example of Hayes’ understanding of the rules governing expert testimony is in his recent appeal of a DUI conviction. At trial, in support of its argument to convict, the State presented the testimony of a state field technician as expert testimony to establish the defendant’s BAC, or blood alcohol content. The technician’s testimony was admitted as expert testimony, over the defense’s objection, and the defendant was ultimately convicted by the jury.
On appeal, Mark Hayes, representing the convicted defendant, presented the case that the field technician’s testimony should not have been admitted as expert testimony. Specifically, Hayes argued that, although the technician acknowledged that some factors will affect that individual’s rate of alcohol elimination, he blindly applied an average figure without accounting for any particular physical characteristics of the defendant. Additionally, Hayes argued that the trial court erred in concluding that the field technician demonstrated the technical background knowledge to qualify as an expert.

“Juries can often be mesmerized by the term ‘expert.’ The important thing is that attorneys make sure that a witness testifying as an expert is properly qualified as such,” said Mark Hayes. The newly revised Rule 702, of the North Carolina Rules of Evidence, follows more closely in line with the Supreme Court’s decision in Daubert v. Merrell Dow Pharmaceuticals, Inc., in that it contains three distinct requirements in order for a witness’s testimony to qualify and be admitted as expert testimony. First, the testimony must be based on sufficient scientific data or facts. Second, the data or facts presented in the testimony must be the product of reliable scientific principles and methods. Finally, the witness must apply those principles and methods reliably to the facts of the given case. In revisiting his appeal in this case, Mark Hayes said, “This new rule represents a more stringent test, which is a good thing because the court system needs to make sure that juries are assigning more credibility to a witness’s testimony because that witness is labeled an expert only if the witness actually qualifies as such under the rule.”

The relevance of this rule change can be seen in all manner of cases. Experts are often used to determine the value of a marital home so as to come up with an equitable division of marital assets in divorce proceedings. Experts are also often seen in medical malpractice cases or in contract disputes involving sophisticated parties. Appellate attorney Mark Hayes said, “The common ground is that the new rule requires a lot for a witness to be qualified as an expert, regardless of the context. Having an attorney who understands those requirements, as well as how to challenge a court’s ruling that a particular witness meets those requirements, is an excellent tool to have for an appeal.”

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