Field sobriety tests (FST) have long been used by law enforcement to determine whether people where driving while intoxicated. The only problem is that these tests are highly subjective, based entirely on the police officer’s opinion at the time. Countless individuals are wrongfully arrested for DUI based solely on a failed field sobriety test.

If you feel that the same has happened to you, know that you’re not alone. Martin & Kent, L.L.C., is an award-winning firm with DuPage County DUI lawyers committed to giving clients our very best. We have over four decades of defense experience and a thorough understanding of DUI laws in Illinois, particularly as they relate to FSTs.

We can fight for your innocence surrounding three of the most common FSTs:

  • Horizontal gaze nystagmus (pen test) – The officer moves a flashlight, penlight, or another object back and forth about 12 to 15 inches from your face, asking that you track the object only with your eyes. While you may think the officer is watching for any head movement, they are supposed to be watching for certain aspects of “nystagmus,” or the jerking of the eye.
  • One-leg stand – An officer will request that you stand on one leg with the other at least six inches from the ground. You then must count for 30 seconds while keeping your balance, finishing up by looking down at your foot. Officers should look for lack of balance control, as well as the lack of ability to follow oral directions.
  • Walk-and-turn – Officers instruct that you walk heel-to-toe in a completely straight line for nine steps, before turning on one foot and coming back in the other direction. Police watch to see if you lose your balance, take too few or too many steps, or otherwise fail to follow directions.


Many people are unaware that the National Highway Traffic Safety Administration (NHTSA) has only sanctioned these three tests. This means that any other FST administered by an officer is not considered legitimate and therefore prosecutors cannot use them against you in court. There are also specific procedures for administering each type of test.

Years of research surrounding FSTs has shown that their accuracy is highly debatable. Even more disturbing, officers are typically more inclined to overestimate your blood alcohol content (BAC) if you agree to take the FST.

We often remind clients that consenting to a field sobriety test is entirely up to you. A police officer cannot force you to take the test and if you refuse to do so, your refusal cannot be held against you later on. The subjective nature of FSTs indicates that it is always better to politely tell the officer no when asked.

If you do undergo field sobriety tests and the officer testifies that you “failed” by showing signs of impairment, our attorneys can still defend against this allegation. First, not all officers have proper training when it comes to field sobriety testing. Did the officer administer each test in the required manner? Did the officer properly observe for the right factors and record all observations in a timely manner? For example, if an officer administers the horizontal gaze nystagmus test without asking you to turn away from flashing police lights, the extra lights can increase nystagmus and skew your results.

In addition, many completely sober individuals may “fail” an FST under certain circumstances. Did police ask you to stand on one foot on an uneven shoulder of the road? Holding your balance on uneven ground can be impossible for most people—with or without alcohol. Any police encounter can cause you to be nervous or flustered, even if you have not been drinking. Nervousness can cause you to become confused or make mistakes when trying to follow instructions. Such mistakes do NOT automatically mean you are intoxicated—they just mean you are human. Our attorneys know this and work to discredit an officer’s assertions that you failed an FST due to intoxication.


Our attorneys develop defense strategies tailored to each specific case. Cases involving field sobriety tests may have a distinct approach from cases only involving chemical testing. Often, if your blood alcohol content (BAC) measures below the legal limit, officers use field sobriety tests as an attempt to gain probable cause to arrest you for DUI. We regularly challenge the observations of police officers on the witness stand to question this type of evidence of your intoxication. This includes an officer’s observations while performing FSTs.

Just because you believe you failed an FST or a chemical test does not mean you should lose hope. Call our criminal defense firm so we can get started protecting your rights today.


While you may have failed your FST and been arrested for drunk driving, all hope is not lost. In fact, this is an excellent starting point for our team to begin shaping your defense. We are prepared to investigate every avenue of your case and use our findings to fight for your most favorable outcome.

The time to act is now. Call Martin & Kent, L.L.C., today at (630) 474-8000 and schedule your free consultation. We practice in DuPage, Kane, and Cook Counties.