In almost all DUI cases, you will be asked to perform Field Sobriety Tests (FST’s). You are not required to do these tests and can refuse to do them. Most people take the tests because they are not told they don’t have to take them. The problem with taking the FST’s are that they have nothing to do with driving impairment and were designed for failure. The officer and prosecutor simply use your failed performance on the tests to prove you were impaired. The good news is that a good DUI attorney can expose the significant flaws of these tests.
3 standardized Field Sobriety tests
There are only 3 standardized field sobriety tests which have been scientifically validated for use in California – horizontal gaze nystagmus, walk and turn and one leg stand. These tests were developed under laboratory conditions to aid officers in their DUI investigations. Although these tests were developed in a laboratory, the reality is that these tests are given in real world conditions under extreme stress and environmental conditions which can significantly affect the results. It is obvious that many people fail these tests and are not under the influence.
False Positive Field Sobriety Tests
Even when the standardized field sobriety tests are administered perfectly (which is rare), they still provide a very inaccurate measure of whether a DUI suspect is impaired. According to NHTSA, for example, the one leg stand test has a 65% accuracy rate and the walk-and-turn test a 68% accuracy rate. This means that if people were convicted based on these roadside tests, one third of them would be innocent and wrongly convicted. Or, viewed another way, when officers arrest DUI suspects based on failing these tests, one in three suspects is wrongfully arrested.