Two of the standardized field sobriety tests have been addressed in previous posts. The column this week will cover another — the horizontal gaze nystagmus. Law enforcement officers in Georgia like to use this test on those suspected of drugged or drunk driving, but is it really all that accurate?
While the walk-and-turn test and the one-leg stand test look for balance issues, the HGN test looks at the ability to follow objects with one’s eyes. Those who are not impaired can typically track an object with their eyes smoothly and accurately. If the eyes bounce or jerk, police consider this a sign of intoxication.
To perform the HGN, a law enforcement officer will first have to give verbal directions and ask if the subject understands what is being asked of him or her. Then, the officer will ask the individual to track an object, such as a pen or light, with his or her eyes. The object is to be held about 12 to 15 inches from the subject’s face.
While there is scientific evidence that the HGN test is accurate, it does not mean that it is foolproof. Administration errors can occur, making the results invalid. Georgia residents who have been arrested and charged for drugged or drunk driving based on the results of the HGN or other field sobriety tests may question the results as part of their criminal defense. An experienced attorney can assist with this and will also be able to help the accused pursue a legal course that will best benefit the situation.
Source: FindLaw, “What Is Horizontal Gaze Nystagmus (HGN)?“, Accessed on May 24, 2017