Field sobriety tests like the walk-and-turn test, the horizontal gaze nystagmus test, and the one-leg stand have long been used to check for driver impairment. These may be given prior to a breath test. Police officers like to use them because they can demonstrate impairment for issues that may not be alcohol-related and wouldn’t show up on a breath test.
But the problem with field sobriety tests is that they are often just wrong. For instance, the one-leg stand test only gets it right about 65% of the time—or two out of every three cases. The walk-and-turn test is a little better at 68%. The horizontal gaze nystagmus test does best at 77%, but that still means that more than two out of every ten arrests could be based on an inaccurate judgment by the officer.
Sober people can fail field sobriety tests
Another important thing to keep in mind is that you could be 100% sober and still fail one of these tests.
For instance, say that you work in a physical, manual labor job. You’re driving home from work when an officer stops you and tells you to do the one-leg stand. You lose your balance. But it’s not because you’ve had anything to drink—it’s just because your legs were physically fatigued when you started the test.
There can also be personal issues that could cause a person to fail the test. Maybe someone is living with a disability that makes it difficult for them to balance or concentrate. They could easily fail a field sobriety test, even if they haven’t been drinking or using drugs.
These tests may be unreliable, but they do lead to arrests. If you’re facing charges, you must know about all of your legal defense options.
