Why field sobriety tests are not accurate

| Aug 25, 2020 | Criminal Defense |

No one wants impaired drivers on the road. And none of us want to be wrongfully convicted of a crime we did not commit. The field sobriety test (FST) was developed by the National Highway and Safety Administration to detect impairment in drivers. Even when this test is administered exactly and under perfect conditions, it is only about 68% accurate.

Nearly one-third of FSTs will bring back an erroneous result. It is therefore in the best interest of most drivers to refuse to take the FST. Why? Because any positive, even a false positive, will be used as evidence against you in court.

The three parts to a field sobriety test

There are three tests that comprise the field sobriety test. An officer will ask you to step out of the vehicle and do the one leg stand, the walk and turn and the eye test. Here is what these tests consist of:

  1. One leg stand: You will be instructed to stand with your feet together, arms at your sides. Then, when instructed, you will be told to raise one foot about six inches off of the ground. Then you will be asked to count “one thousand one” and up until told to stop. If you sway, use your arms to balance, hop or put your foot down, you fail.
  2. Walk and turn: You will be instructed to take nine “toe to heel” steps, turn as directed and then take nine steps back. You may be asked to count out loud and to tell the officer how many steps you took. If you lose your balance, start or stop before being told to, do not touch “toe to heel,” use your arms to balance or do not turn exactly as instructed, you fail. Page 12 of the law officer training manual cites this test as 68% accurate.
  3. Eye test: Your eyes will be examined for pupil size and general appearance. You will be instructed to follow the officer’s pen or finger back and forth. If your eyes jerk while the test is being administered you will fail.

As you can see, someone who is sober may have a hard time executing these tests on a dark roadside late at night. Additionally, an officer trained in FST administration should not only explain the directions but also demonstrate how to perform the task. This step is often missed by law enforcement.

While Indiana implied consent laws require you to submit to a chemical test administered at the police station, you can refuse to take the FST with no negative legal consequences. This is most likely in your best interest.