| Almost all DUI investigations include having a California | | | | test given the complexity of the instructions. |
| DUI suspect perform various balance and coordination | | | | The one leg stand is the easiest test to administer, but |
| tests. These tests are referred to as field sobriety | | | | for some suspects, the hardest to perform. Being |
| tests or FST's. The theory behind these tests is that | | | | asked to place your hands at your sides and balance |
| they test a person's ability to divide attention. Driving is | | | | on one foot while keeping the opposite leg perfectly |
| portrayed as a divided attention task. One has to both | | | | strait and look down at your feet can be hard to do |
| operate the automobile and also pay attention to other | | | | by the side of the road under the stress of a law |
| cars, pedestrians, and traffic controls on the road. | | | | enforcement detention at 3:00 in the morning. I had one |
| There are several FST's. The most common are the | | | | trial where I asked the officer to demonstrate this test. |
| horizontal gaze nystagmus, walk and turn, one leg | | | | The officer struggled, shaking and hopping before the |
| stand, Rhomberg balance, finger to nose, alphabet, and | | | | jury. He failed the test, but said it was due to being |
| number count. Only three of these tests, the horizontal | | | | nervous in court. Why did the officer fail to give my |
| gaze nystagmus, walk and turn, and one leg stand are | | | | client the same excuse? |
| recognized by the National Highway Traffic and | | | | NHSTA's manual claims that if the three SFST's are |
| Safety Administration (NHSTA) as having a statistical | | | | performed correctly and scored correctly, than they |
| validity. These three tests are called Standardized Field | | | | can have an accuracy rate of 91% for predicting a |
| Sobriety Tests (SFST's) | | | | BAC of .08 or above. These studies are of |
| The horizontal gaze nystagmus test consists of the | | | | questionable validity because they were all conducted |
| arresting officer asking the DUI suspect to keep their | | | | by law enforcement agencies under unrealistic control, |
| head still and follow a stimulus such as a pen or finger | | | | sample and verification conditions. It is important to |
| while the officer moves it in front of their face. The | | | | emphasize that the 91% rate would only apply in a |
| officer is looking to see if the eyeballs jerk involuntarily | | | | perfect investigation where the tests were done |
| (nystagmus). This is the SFST that has the greatest | | | | correctly. In the vast majority of cases, a good DUI |
| aura of scientific validity. However, in reality, it is junk | | | | defense attorney can find the defects to help |
| science. There are some people who have | | | | undermine the value of this evidence in the |
| nystagmus that is natural or caused by a medical | | | | prosecution's case. |
| condition. The arresting officer can cause nystagmus | | | | There are common misunderstandings of the role of |
| by moving the stimulus too fast, holding it out too long, | | | | FST's. Many people believe that FST's can show |
| or holding it too close to the suspect's face. Also, | | | | impairment or prove that a suspect has a certain blood |
| jerking motions by the arresting officer can cause | | | | alcohol level. The proper role of the FST's as testified |
| nystagmus. As a result, this test is rarely performed | | | | to by the creator of the FST's is to help the arresting |
| correctly and properly by arresting officers. | | | | officer decide to arrest the DUI suspect and take the |
| The walk and turn is a deceptively simple test, but in | | | | DUI suspect to have a chemical test performed. That |
| reality it is complex to administer. Giving the proper | | | | is really the only purpose for FST's. Nevertheless, |
| instructions and demonstrating the test take practice | | | | many prosecutors and others continue to insist that |
| and experience. Failure to start the person off on the | | | | the test performance on its own is sufficient for |
| correct foot can sabotage the entire test and set the | | | | conviction. |
| person up for failure. Minor sins like raising arms more | | | | It critical for the DUI defendant to obtain a DUI lawyer |
| than six inches for balance are counted against the | | | | who understands the proper role and weaknesses of |
| test subject. There are many places to make | | | | field sobriety tests and can effectively communicate |
| mistakes. Sober people make many mistakes on this | | | | these issues to juries and judges. |