The horizontal gaze nystagmus (HGN) test is a field sobriety test given by an officer who suspects a driver’s ability to drive is impaired by alcohol. When performing the HGN test, the driver must hold his or her head steady while following a stimulus with his or her eyes. The officer watches for a wobble in the eye as it is following the stimulus – this wobble is an involuntary physiological response to alcohol (though other causes may also exist). In State v. Blackwell, the Court of Special Appeals reversed Blackwell’s alcohol-related charges due to the officer not having been qualified as an expert during his trial, thereby making his testimony inadmissible. Further, the results of the HGN test may show the presence of alcohol, but this does not necessarily show driver impairment. If you have been charged with DUI or DWI, call Azari Law at 301.362.3300 to discuss your case today.