If a police officer suspects a drunk driver in Jackson, Mississippi, the officer may pull the driver over to conduct field sobriety tests. These tests check for driver impairment by having them perform certain activities. While there are several tests, three tests have been found to be the most accurate.
Types of standard field sobriety tests
The horizontal nystagmus gaze test checks for DUI by having the driver follow an object, such as a pen, finger or light, with their eyes. The officer tests each eye and watches for three clues, which are smooth following, involuntary jerking at 45 degrees and maximum deviation. Maximum deviation means the eye can’t move any further to the side and jerks within four seconds in that position.
The one-leg stand test tests the driver’s balance by having them stand on one leg for several seconds while counting. The officer watches for the driver swaying, putting the foot down early, hopping or using the arms for balance.
The walk-and-turn test requires the driver to walk nine steps, heel to toe, in a straight line. The driver should complete the test by turning on one leg and walking nine steps back the other way. This test checks how well the driver follows instructions, and the officer watches for cues such as getting off the line.
Accuracy of sobriety tests
The accuracy of field sobriety tests to determine DUI is debated since they aren’t based on proven scientific methods. Even sober drivers may have trouble passing them in certain conditions, such as uneven terrain, weather and high-traffic areas.
Some medical conditions could skew test results, which include inner ear trouble, neurological conditions, allergies and musculoskeletal disorders. The officer might lack the proper training or give clear instructions on how to do the tests.
Drivers have the right to refuse field sobriety tests in Mississippi without penalty. If drivers are charged with DUI after performing a test, they may be able to apply several valid defenses if they believe the tests are inaccurate.