Police bodycam footage shows an officer explaining and demonstrating the horizontal gaze nystagmus test, a key part of the standardized field sobriety test battery. The officer tells the driver to track the movement of a pen with only his eyes, looking for involuntary jerking associated with impairment. Afterward, the walk-and-turn test is introduced, requiring nine heel-to-toe steps, a small turn, and nine steps back. These roadside tests are designed to give officers probable cause to arrest impaired drivers. Anthony Folkes, of Fairfield, was indicted on two felony counts stemming from a January arrest when he placed a Hamilton police officer in a chokehold. Folkes was pulled over for a busted passenger headlight and no license plate light, then resisted arrest as he was being placed under arrest following a failed field sobriety test. #bodycam #sobrietytest #walkandturn #horizontalgaze #trafficstop #DUIenforcement