The Oregon Court of Appeals has reversed a conviction for driving under the influence of intoxicants (DUII) against Emily Thornley. The court ruled that the trial court made a mistake by excluding expert testimony that could have shown Thornley was experiencing withdrawal from benzodiazepines at the time of her arrest. This decision affects Thornley directly and highlights the importance of expert evidence in DUII cases.

The case, State v. Thornley, was filed under docket number A184499. The ruling was issued on November 12, 2026, by Judge Tookey, along with Judges Egan and Jacquot. This ruling emphasizes the necessity for trial courts to allow relevant expert testimony that could impact the outcome of a case.

Background

Emily Thornley was convicted in the Washington County Circuit Court for DUII. The case arose after Thornley was arrested, with law enforcement alleging she was impaired by cannabis. However, Thornley contended that she was actually suffering from withdrawal symptoms related to benzodiazepine, a class of medication often prescribed for anxiety and sleep disorders.

During the trial, Thornley sought to introduce expert testimony to support her claim that she was not impaired by cannabis but was instead experiencing withdrawal symptoms. The trial court, however, excluded this expert testimony, leading Thornley to appeal the decision. The appeal was based on two main arguments: that the trial court erred in excluding the expert's opinion and that the error was not harmless.

The Ruling

The Oregon Court of Appeals ruled in favor of Thornley, stating that the trial court's exclusion of the expert testimony was erroneous and not harmless. Judge Tookey noted, "The exclusion of expert testimony diagnosing defendant with benzodiazepine withdrawal was not harmless." The court emphasized that the exclusion of this evidence could have significantly impacted the jury's verdict.

The court explained that the trial court had the opportunity to consider the relevance of the expert testimony during an evidentiary hearing. Despite this, the trial court decided not to allow the diagnosis to be presented to the jury. The appellate court found that the issue of whether Thornley was experiencing withdrawal symptoms was a central factual question in the case, making the expert testimony crucial to her defense.

Impact

This ruling has significant implications for DUII cases in Oregon. It underscores the importance of allowing expert testimony that can provide critical context about a defendant's condition at the time of an alleged offense. The court's decision indicates that excluding such evidence can lead to a reversal of a conviction if it is deemed central to the case.

The decision also reinforces the principle that trial courts must ensure that all relevant evidence is considered. The ruling could potentially influence how future DUII cases are handled, particularly those involving medical conditions that may affect a defendant's state of mind or ability to operate a vehicle safely.

What's Next

Following this ruling, the case has been reversed and sent back to the lower court for further proceedings. Thornley may have the opportunity to present her defense with the expert testimony included. Details regarding any potential appeals or related cases were not available in the court filing.