A police officer who stops you for the suspicion of drunk driving will have to try to ascertain if you are actually impaired. This can be rather complicated because some of the testing that must be done is subjective. Field sobriety tests can fall under this subjective label because the results are based solely on the interpretation of the results as noted by the officer.
Field sobriety tests are usually done before other tests, like Breathalyzers, are done. The standardized field sobriety test is a three-part test that includes a walk-and-turn, a horizontal gaze nystagmus and one-leg stand test. These tests are sometimes used in conjunction with non-standardized tests that could include having to recite the alphabet or touching your nose with a finger while your eyes are closed.
The walk-and-turn test requires that you take nine heel-to-toe steps and then turn around to return to your starting point. The horizontal gaze nystagmus test is one that requires you to watch an object while the officer watches your eyes for abnormal jerking. The one-leg stand requires that you balance on one leg with the other leg six-inches above the ground, and doing things like using your arms to balance could be indicative of impairment.
The officers who are doing these tests must look for specific markers that could indicate the person is too intoxicated to drive. As we discussed a few weeks ago, these tests can produce false positive results in some cases. If you have a drunk driving case that has a field sobriety test as a component, you should explore your options for presenting a defense.
Source: FindLaw, “Field Sobriety Tests,” accessed Oct. 28, 2016