The PA Superior Court has held that a York County trial court erred in declining to qualify a defense expert as an expert in the methodology behind standard field sobriety tests. Commonwealth v. Taylor, No. 715 MDA 2018 (Pa. Super. 5/6/2019).

Taylor was convicted of driving under the influence of drugs and endangering the welfare of a child.

At trial, “the Commonwealth relied heavily on the arresting officer’s testimony which primarily focused on how poorly Taylor performed on the tests. The officer testified that Taylor’s performance indicated impairment due to drug use.” The defense planned to “rebut the officer’s testimony with the opinion of its own witness, Dr. Lawrence Guzzardi, a medical toxicologist and physician. This witness planned to testify, in part, that there is no scientific basis to rely on field sobriety tests to detect drug impairment because they have only been validated to reveal intoxication from alcohol.”

The trial court concluded that Dr. Guzzardi’s lack of practical experience precluded him from opining on “the methodology used to construct standardized field sobriety testing procedures.”

However, the appellate court concluded that “whether field sobriety tests have been validated has nothing to do with practical experience. The rules of evidence do not require a witness to have hands-on skills in a given area in order to testify as an expert on its theoretical aspects.”

In this case, “Dr. Guzzardi would have opined that field sobriety tests are not scientifically proven methods of detecting drug impairment.”

Accordingly, “the witness should have been permitted to testify that they have never been scientifically validated as reliable indicators of drug impairment.”

The Superior Court also concluded that the error was not harmless, stating that “if admitted into evidence and accepted by the jury, this expert opinion would have rebutted the officer’s conclusion that Taylor was impaired by drugs. It was for the jury to weigh that evidence, but it never got the chance.”

Judgment of sentence vacated, case remanded for a new trial on all counts.


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