A Field Sobriety Test, or “FST”, is a common method that police officers use to determine whether a driver is drunk.  A person suspected of drunk driving (DUI or DWI) may be requested to undergo any of the following tests:

  • Stand on one foot while counting
  • Walk an imaginary line, heel to toe (as if on a tightrope)
  • Touch a finger to the nose slowly
  • Recite the alphabet backwards or count backwards
  • Horizontal gaze (“nystagmus” test)- the driver is asked to follow a pen about a foot from their face as the officer moves it from side to side, looking for jerks in the eyeball movement

If the driver is unable to perform the requested movements, or appears suspicious in their actions, the officer may use the results from the field sobriety test as evidence of the person’s intoxication. 

Are Field Sobriety Tests Mandatory?

While one should cooperate fully with police authorities at all times, drivers should be aware that field sobriety tests are not required by law in most states.  A driver may refuse to take a field sobriety test; however, their refusal will likely be recorded in the police officer’s written report.

On the other hand, other requests by the police may be mandatory.  For example, if the police officer requests the driver to submit to a breathalyzer exam, the driver may be required by law to take the test.  In some states, refusing to take a breathalyzer test can result in a suspended driver’s license. 

Thus, you may wish to check the highway laws of your state before refusing to take a field sobriety test or any other type of DUI test.

Can I Challenge the Results of a Field Sobriety Test?

Yes- proving a DUI violation often depends heavily on the results of a field sobriety test for evidence.  If you feel that the results of a field sobriety test were in error, you may be able to challenge the admissibility of the FST evidence at trial. 

When challenging field sobriety test evidence, a defendant may present several factors, including:

  • The driver’s physical condition, age, weight, and driving experience
  • Whether the driver was ill, used medications, or contact lenses (may interfere with eye movements)
  • Roadside conditions during the field sobriety test
  • The training, skill, and experience of the police officer in conducting field sobriety tests
  • State standards when applying DUI or DWI laws

Most field sobriety tests are conducted in a manner that allows them to be videotaped using a camera installed in the patrol car.  Thus, if an FST is being challenged, video footage of the test will probably be used as evidence by the state. 

Also, some of the methods employed in an FST have been noted to be fairly inaccurate.  For example, the nystagmus test (following a pen with the eyes from side to side) has been considered to be unreliable for the purposes of determining intoxication.  Many courts will reject the results of a nystagmus test when weighing evidence in a DUI case.

Do I need a Lawyer to Challenge the Results of a Field Sobriety Test?

If you will be challenging the results of a Field Sobriety Test, it is highly advisable that you contact a DUI/DWI lawyer.  Your attorney will be able to provide you with the right advice on how to proceed with defending your claim.  Every state has different drunk driving laws, and a lawyer can help explain how the laws of your individual state apply to your case.  Many states allow persons to submit evidence challenging FST results.