The answer is you don’t. You do not know.
Field sobriety tests are voluntary, but most officers don’t emphasize that fact to people. You can always refuse them, and you should always refuse them. Because there’s really no way to determine whether or not a field sobriety test is being performed properly.
There’s a range of numbers that officers use to rate a performance on a field sobriety test. They may see somebody walking in a line and say, “On a scale of 1 to 10, I’m going to give that person a 6.” For the next person, they say, “I’ll give that person a 7,” the 7 being worse than the 6.
However, there’s no mechanism to show the difference between the 6 and the 7. There’s no mechanism that shows the difference between any of these numbers. A lot of it is really fuzzy science. Officers will just pick a number out of the air, based on their training and experience, that they think represents a person’s performance.
It’s very hard to challenge that later on in court. Unless you have a lawyer there with you while you’re doing these tests, there’s really no way for anyone to challenge what the officer says about your performance on these tests.
Also, in my experience, very few people who are given a field sobriety test actually pass it. If a police officer thinks you’re drunk, it’s unlikely that he or she is going to say you passed your field sobriety test.
Sometimes, there are other factors working against you. For example, you may have an ailment that affects your performance on a field sobriety test. In my experience, I have had clients with physical problems, such as a bad hip, that impeded their ability to do what they officers asked of them. An officer might say, “You were not able to stand on one leg, you must be drunk.” When in fact, the client was unable to stand on one leg because he or she had a hip or a knee that was degenerating.
For these reasons and many more, I highly recommend that you refuse field sobriety tests if you are pulled over for a DUI.
For more information, feel free to contact us.