State v. Quaale

¶1 The arresting trooper in this DUI (driving under the influence) trial testified that he had “no doubt” that the defendant was impaired based solely on a *194horizontal gaze nystagmus (HGN) test. We hold that the testimony was an improper opinion on guilt and affirm the Court of Appeals.

FACTS

¶2 Washington State Patrol Trooper Chris Stone saw a truck, driven by Ryan Quaale, speed by in a 25-mile-per-hour zone on a residential street. Trooper Stone’s radar captured Quaale’s speed at 56 miles per hour. Trooper Stone activated the lights on his patrol car and attempted to pull the truck over. In…