Field Sobriety Tests and DUI Charges: Challenging FST Results
Savannah DUI Lawyer
The Savannah DUI attorneys at The Schneider Law Firm have tried many cases where the results and reliability of the field sobriety tests used in an arrest and prosecution for DUI have been challenged. In the state of Georgia, as in many other states, when a driver is pulled over and is suspected of driving under the influence of alcohol, police officers will routinely administer a test or series of tests to determine if the driver is impaired. The National Highway Traffic Safety Administration (NHTSA) developed a battery of three tests called the Standardized Field Sobriety Test (SFST) which most law enforcement agencies now use. The SFST consists of:
- The Horizontal Gaze Nystagmus (HGN)
- The One Leg Stand (OLS) and
- The Walk and Turn (WAT)
Horizontal Gaze Nystagmus
The HGN test measures the responses of a subject's eyes as they follow an object, such as a pen held by the police officer, from side to side. The eyes will involuntarily jerk naturally as they follow an object from side to side, but when impaired by alcohol, this jerking movement is exaggerated. The eyes of a person who is not impaired by alcohol will follow the object from side to side smoothly back and forth with minimum jerking movement. However, the person who is impaired by alcohol will have trouble following the object smoothly from side to side. If an officer observes this, and other slight irregularities, it is assumed that the subject is impaired by alcohol.
One Leg Stand
The one leg stand test measures a subject's balance. The officer will ask the subject to stand with one foot on the ground and one foot off the ground approximately 6 inches. While the foot is in the air, the subject is asked to count aloud by thousands until they are instructed to put the foot back down. While timing the subject for 30 seconds, the officer will look for four indicators in the subject; their body swaying from side to side, using their arms to keep their balance, hopping to maintain their balance, and putting their foot down before being instructed to do so. If the subject exhibits 2 of the 4 indicators, it is assumed that the subject is impaired by alcohol.
Walk & Turn
The walk and turn test requires a subject to listen to and follow some simple instructions while performing a simple physical movement. It is based on the notion that impaired persons have trouble listening to spoken instructions and performing a physical movement at the same time. The subject is usually asked to walk for nine steps, heel to toe, in a straight line, turning on foot, and returning back to the place of beginning in the same way. If the subject makes mistakes such as starting before being instructed to do so, or stops to regain their balance, steps out of the straight line, makes an incorrect number of steps, improperly turns around or doesn't touch their heel to their toe, they are considered impaired.
Field Sobriety Tests Are Not 100% Accurate
Studies have shown that the assumptions made using the results of a field sobriety test are only accurate 77% of the time, for the most effective test, the HGN. Therefore, there is significant room for argument as to their effectiveness in determining whether or not someone is impaired and should be convicted of a DUI. The test can become the only measure of impairment when blood or breath tests have been challenged and suppressed at trial. If you have been charged with a DUI and you had to take the field sobriety test, please contact us today for a free consultation.