Police officers will often request drivers to perform field sobriety tests if they suspect that the driver is impaired. For instance, say that a police officer pulled someone over for running a stop sign. If the driver has slurred speech and bloodshot eyes, the officer may believe that they have been using alcohol or even prescription drugs, marijuana or other substances.
If the driver then fails these field sobriety tests, they can be arrested on suspicion of impairment. They may also be asked to take a breath test to determine their blood alcohol concentration (BAC). But the field tests start the process, and an arrest is possible even without a breath test. Since these field tests are so often used, people generally assume that they must be accurate. But is that really the case?
The inaccuracy is well known
The truth is that the authorities have known for decades that field sobriety tests are not close to being perfectly accurate. Even when they are all used together, they are less than 90% accurate. For every 10 drivers who get pulled over on suspicion of impairment, two could be sober and still fail a field sobriety test.
The three tests that are normally used are the walk-and-turn test, the one-leg stand test and the horizontal gaze nystagmus. If only one test is used the accuracy is even less than if the driver is asked to perform all of them – a mere 65% for the one-leg stand, for instance.
It’s important for drivers to be aware of this inaccuracy, especially if they believe that they have failed the tests and been arrested when they were actually not impaired. If you find yourself in this position, you need to know about your legal defense options.
