Field Sobriety Tests in Montana

Field sobriety tests (FSTs) encompass several roadside tests used to determine whether a suspect is impaired by alcohol or drugs. They are often performed on DUI suspects to assist an officer make the decision whether to arrest the driver. In theory, these tests directly assess impairment by focusing on the skills needed to be a safe driver.

A major problem with FSTs is that the results are very subjective, relying on the opinion of the officer administering the test to determine the outcome. This also makes them very difficult to challenge later in court. According to one study, many sober people are unable to perform the tests properly. This study found a false positive rate of 23%. Many FSTs are “divided attention tests” that try to test the driver’s ability to perform physical and mental multi-tasking.

Some of the most common FSTs are:

  • Horizontal Gaze Nystagmus – moving an object left and right to examine how the eyes move when they follow it.
  • Walk-and-Turn (heel-to-toe in a straight line)
  • One Leg Stand
  • Finger to Nose
  • Recite all or part of the alphabet. A common myth is that suspects are required to recite the alphabet backwards. Most people can’t do this sober, let alone when intoxicated.
  • Touch each finger of hang to thumb counting each touch
  • Count backwards from a number (such as 30 or 100)

More and more, these tests are being standardized into a three-pack. They include the Horizontal Nystagmus Test, the walk and turn test, and the one-leg stand.

After administering the FSTs, the officer will make a determination whether there is probable cause to make an arrest. If he believes there is, he will place the driver under arrest and transport them to jail. Usually at the jail they are given either a blood or breath test to analyze the level of alcohol in their blood.

Call Now for a Free Case Review and Consultation
(406) 752-6373

or Click Here to Contact me Online