State v. Whitmore

Expert testimony of a scientific nature is so inherently persuasive that not only must an expert's credentials be testified to a jury, but a foundation must be built showing their methodology is scientifically valid.

Defendant appealed his conviction of driving under the influence of intoxicants (DUII). At trial, the State’s expert used retrograde extrapolation as evidence of Defendant’s level of intoxication prior to arrest. Defendant filed a motion to exclude this evidence because it lacked scientific foundation, which the trial court denied. The State’s expert portrayed her expertise as scientific, noting a background in forensic science and studies of blood alcohol chemistry. The State did not lay a foundation for the validity of its expert’s methodology. Expert testimony of a scientific nature is so inherently persuasive that not only must an expert's credentials be testified to a jury, but a foundation must be built showing their methodology is scientifically valid. The Court held that the trial court erred in not requiring the State to show that its expert’s methods were scientifically valid. Reversed and remanded.