If a police officer pulls you over and believes that you may be under the influence, one of the first things he or she will do is to give you field sobriety tests. These generally include the walk and turn, the one-leg stand and the horizontal gaze nystagmus test. They are considered the three main tests, and things like being asked to recite the alphabet are actually quite rare.
You can get arrested if you fail these tests. Even if you later take a breath test that puts you at a BAC of 0.07% or lower, which is under the legal limit, you could face charges because the officer will claim that you were impaired, no matter your blood alcohol concentration.
Therefore, knowing how well these tests work is critical. One would assume that they are 99% accurate if police departments use them so often and base arrests on them, but that is unfortunately not the case.
The true percentage is lower than you’d think
According to some studies, a police officer who uses the three main field sobriety tests all together will be correct in only 8 out of 10 cases (82% of the time). If he or she just uses one test, the accuracy falls dramatically.
Now, someone could defend these tests by pointing out that they work in most cases, and that is true, but the word most is highly deceptive. Even a test that was wrong 49% of the time would work “in most cases.” There are serious issues with field sobriety tests, and those who are facing charges must know what legal options they have to raise an effective defense.