In addition to asking to test your blood alcohol content (BAC) a Missouri police officer may ask you to perform several field sobriety tests in order to determine whether or not you are exhibiting any signs of intoxication.
Although the tests are meant to determine your balance, coordination, and mental clarity, they don’t always accurately portray your sobriety – and they are not required by Missouri DWI law.
What Are Field Sobriety Tests?
In Missouri, you may be asked to complete the Standardized Field Sobriety Test (SFST), which is actually comprised of three different tests:
- The horizontal gaze nystagmus test (HGN). This tests the involuntary twitching of your eyes when intoxicated and following an object from side-to-side.
- The walk-and-turn (WAT). This tests your balance as well as your ability to follow instructions as you walk in a straight line, heel to toe, before turning around and walking back.
- The one-leg stand (OLS). This tests your balance by having you stand on one leg.
Why Field Sobriety Tests Aren’t Always Accurate
Unlike tests of your blood alcohol level, field sobriety tests are subjective: they are always interpreted by the officer, and they decide whether you pass or fail.
Secondly, two out of three of the field sobriety tests simply test your coordination, balance, and ability to follow directions – issues that could be affected by a number of factors, including:
- Being nervous or scared.
- Being tired.
- Having a physical disability.
- Having a mental health condition.
- Wearing certain types of clothes or shoes.
For example, a woman wearing high-heeled shoes, or a man wearing cowboy boots, may have trouble walking in a straight line or balancing. A person with a mental health issue may have difficulty following directions. And anyone who is nervous about a run-in with police might do poorly on all of the tests.
Should You Take The Field Sobriety Tests?
Taking a blood or urine tests to determine your blood alcohol level is the most accurate way to determine whether or not you are driving while intoxicated. Consent to take a blood alcohol test is implied under Missouri’s implied consent law.
On the other hand, field sobriety tests are not required by law and do not often accurately reflect a person’s level of intoxication. The choice is solely up to you.
Contact A St. Louis DWI Attorney About Your Drunk Driving Case
If you have been charged with a DWI, DUI, or other alcohol related driving offense in Missouri and aren’t sure what to do, talking to an experienced drunk driving attorney in St. Louis about your case can help you get answers to your questions and formulate a plan of action. For more information, get a copy of our FREE Missouri DWI Survival Guide, or contact our offices today.