Most field sobriety tests used to identify drunk drivers are not based on objective observations, but rather the subjective opinion of a police officer. The accuracy of such tests can be challenged if you are charged with operating while intoxicated (OWI) in Ann Arbor.
Read on to learn more about flawed field sobriety tests results and how to challenge them.
Field Sobriety Test Overview
Before a police officer can charge you with an OWI, he or she must first establish probable cause to arrest you for such a crime. One of the primary ways law enforcement officials establish probable cause is by conducting field sobriety tests. The physical evidence taken from such tests, along with other factors such as driving infractions, will permit an officer to arrest you and take you into custody for further investigation of your blood alcohol content.
A field sobriety test consists of a series of physical and mental exercises. For instance, a police officer may request that you walk in a straight line while looking forward. Generally, there are three standardized field sobriety tests that may be administered:
The Walk-and-Turn Test
One Leg Stand
The Horizontal Gaze Nystagmus Test
As mentioned above, not all field sobriety and chemical tests produce accurate results. Recent studies found that officers who use the standardized field sobriety test model incorrectly assessed drivers' intoxication levels 30% of the time.
Additional reports show a wide varying range of data regarding the accuracy of field sobriety tests. In particular, a report regarding the accuracy of field sobriety tests was conducted by Tharp, Burns, and Moskowitz to determine how accurate law enforcement observation results were in conducting such tests. They reported accuracies of 77% percent for the horizontal gaze nystagmus test, 68% for the walk and turn test, and 65% for the one leg stand the test.
In contrast, a report issued by Stuster and Burns found greater accuracies in making arrest decisions on the basis of standardized field sobriety test results. They reported accuracies of 88% percent for the horizontal gaze nystagmus test, 79% for the walk and turn test, and 83% for the one leg stand test.
Note, the test results shown in both reports were based upon the amount of an individual's blood alcohol content (BAC) level. In the report issued by Tharp, Burns, and Moskowitz, the BAC level was .10. The report issued by Stuster and Burns used a BAC level of .08%. There are several more reports that have conflicting data. Thus, every field sobriety test situation will have different results.
How to Challenge Field Sobriety Tests
Police officers are supposed to administer standardized field sobriety tests in accordance with the guidelines set by the National Highway Traffic Safety Administration. Such tests can be challenged for their reliability.
You can challenge whether or not the officer administered the tests correctly. For instance, if an officer does not administer the test in the appropriate environment (e.g. non-slippery surface), then the evidence collected from the tests can be challenged. If you have a physical condition that subjected you to failing the tests, then you may be able to challenge the officer's observation.
Contact Washtenaw County drunk driving attorney Stacey Washington for a case evaluation if you have been arrested and charged for an OWI.
Standardized Field Sobriety Testing