Defending Failed Field Sobriety Tests

man taking field sobriety tests next to a police officer

Defense From a Chicago DUI Lawyer

After a police officer stops you under the suspicion that you are driving under the influence (DUI), one of the first things they will do is ask you to step out of your vehicle. By careful observation, an officer will determine whether you might be intoxicated and will likely conduct field sobriety tests on you.

msn slumped oever steering wheel, holding a beer
1 2

Standard Field Sobriety Tests

There are many such tests, but only three that are recognized as Standardized Field Sobriety Tests by the National Highway Traffic Safety Administration.

These include:

  • One Leg Stand – A driver must stand with one leg raised about six inches off the ground and maintain his or her balance. This test is used to check a person’s coordination and balance.

  • Horizontal Gaze Nystagmus – A person is asked to follow a light or object with his or her eyes back and forth. If person has alcohol in his or her system, there is normally an involuntary jerky movement of the eyes from side to side.

  • Walk and Turn – A person is asked to walk heel to toe in a certain direction for a set number of steps, then turn around and repeat the procedure. The officer evaluates the person’s ability to follow the instructions, his or her balance and coordination in doing so.

If you have been stopped for driving under the influence, contact a Chicago DUI attorney from my firm right away to begin the process of defending you against the charges.

policeman giving breathalyzer to drunk driver showing refuse gesture, blurred background.

Are field sobriety tests accurate?

For field sobriety tests to produce the most accurate results, they must be administered in a very specific way. Three tests in particular must be administered: the Horizontal Gaze Nystagmus (HGN), Walk-and-Turn (WAT), and One-Leg Stand (OLS). The results of these tests are not always 100% accurate, however, even when properly administered.

According to the NHTSA (National Highway Traffic Safety Administration), these tests may yield results of varying accuracies*:

  • Horizontal Gaze Nystagmus (HGN) – proper classification of approximately 88% of subjects.
  • Walk-and-Turn (WAT) – approximately 79% accuracy.
  • One-Leg Stand (OLS) – accurate in approximately 83% of subjects.

When all three tests are administered accurately, they may yield accurate results in 91% of cases. It is possible that other factors – ones not related to drugs or alcohol – could lead to a “failed” field sobriety test:

  • Naturally poor balance
  • Preexisting medical conditions affecting balance or vision
  • Age
  • Weight
  • Existing or previous injury
  • Nervousness
  • Exhaustion

Even the shoes the driver is wearing can affect his or her performance of a field sobriety test. These tests gauge balance, coordination, and the ability to follow instructions – which can all naturally differ from person to person.

Challenging the Field Sobriety Test

Although these tests may be an aid to an officer, they can easily be challenged in court. If the officer did not follow the exact procedure required during the administration of these tests, they can be disputed as valid evidence. A driver having a medical or physical condition that could affect the outcome of these tests can also be brought to bear when fighting your DUI charges.

At my criminal defense firm, the Law Offices of Mitch Furman, I know all of the possible legal challenges for DUI and for fighting field sobriety tests. I will work hard to get your charges reduced or dismissed and will give you the personal attention you deserve.

Contact my Chicago criminal defense firm today to schedule a free consultation!

Contact Our Firm

Our Posts

Law Offices of Mitch Furman

77 West Wacker Drive

Suite 4500

Chicago, IL 60601

312-236-7078 Office – 312-498-8421 Direct

Google Privacy Policy and Terms of Service apply.