Facts On Field Sobriety Tests Your Attorney Should Know

Barnes & Fersten Law Firm

Barnes & Fersten Law Firm

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You’re at an evening social gathering, having a nice time. You’ve had a few drinks, but you still feel completely in control of your faculties. You decide to leave the party and head home in your vehicle. As you turn the corner not far from the house, you see flashing police lights coming up the street towards you. You’ve been drinking, and the police officer pulls you over. The officer then asks you to take a series of sobriety tests to determine if he should arrest you for driving under the influence (DUI). How do you respond?

When You're Pulled Over For DUI

If you’re going to get a DUI, it’s likely going to happen after a police officer pulls you over. The initial contact may have been due to a broken headlight or tail light, you ran a stop sign, or you were speeding. Whatever the reason an officer stops you, he has the right to ask you to participate in a field sobriety test if he sees signs of impairment such as the odor of alcohol on your breath, slurred speech, or physical problems with your coordination or movements.

The Field Sobriety Test

When a police officer investigates a suspected DUI, they will often have the person perform certain tasks in order to judge their level of intoxication. Some of these tasks or tests are standardized for DUI stops, but some are created by individual police departments–or even individual police officers. In the state of Tennessee, you have the right to refuse to take part in a field sobriety test. If you agree to a field sobriety test, police are searching for a variety of indicators of intoxication using a wide range of techniques.

There are three standardized tests for which the National Highway Traffic Safety Administration (NHTSA) has prescribed very specific training and administration. These tests are the Nine Step Walk and Turn Test, the Horizontal Gaze Nystagmus Test, and the One Leg Stand Test.

There are several other tests not included in this standardized three-test battery. If an officer asks you to perform one of these non-standardized tests, your attorney should challenge the validity of this evidence due to its lack of standardization.

Walk And Turn Test

The walk and turn test requires the subject to walk in a straight line, touching heel to toe, walking nine steps, making a turn with a series of small steps, and returning nine steps in the same fashion–all without stepping off the line, missing heel to toe, or raising their arms for balance.

There are 8 possible clues that an officer is looking for to indicate intoxication, and according to the original NHTSA study, 2 or more clues indicates a blood alcohol level over .10%. There are many ways a DUI suspect can indicate a clue on the walk and turn test. For instance, missing heel to toe on just one out of the eighteen steps indicates a clue; the same is true for stepping off the line just once.

Even though this is a difficult test to pass, there are specific things that your attorney should look for. For instance, did the officer correctly instruct and demonstrate the walk and turn test? If not, it would not be fair to count the test against you. Also, was the test performed on a flat, non-slippery surface, and were heels or boots allowed to be removed? If not, the test may be invalid. Finally, was the person tested a reasonable candidate to take the test, or would they fail whether intoxicated or not due to a medical condition? Even when the test is perfectly instructed by the officer, it may not be conclusive evidence of DUI.

Horizontal Gaze Nystagmus (HGN) Test

The Horizontal Gaze Nystagmus test is a common field sobriety test carried out by police officers. Nystagmus occurs when someone moves their eyes rapidly and unconsciously while attempting to focus on an object, which can be an indication that they have consumed intoxicants that are impairing the brain’s functions. However, these are not dependent upon any type of substance usage alone.

The police may suspect that you’re under the influence if your eye movement is quick and errant while attempting to focus on an object. However, there are circumstances that can impact an HGN test, including wind and rainy conditions, blinking lights, having damaged or weak vision, or even something as simple as allergies could cause nystagmus in one’s HGN test.

Additionally, this is a very difficult test to correctly administer and score, and should be administered by someone with a scientific or medical background. Tennessee appellate courts have held that the HGN test is a scientific test, and for that reason it is rarely used as evidence in a DUI trial, because it is rare that a police officer qualifies as a scientific expert on nystagmus. If the State cannot provide an expert witness to discuss the HGN test in detail, the test will be inadmissible at trial.

One Leg Stand Test

The one leg stand requires the person being tested to stand on either leg with their other leg extended out approximately six inches off the ground, with hands down by the person’s sides and with their toe pointed out. There are four clues that officers are looking for on this test, including swaying, hopping, putting a foot down, and raising arms for balance. Any two of these clues, if present even once, indicates a blood alcohol concentration of .10% or greater according to the NHTSA study.

However, any failures by the officer to correctly instruct, administer, or score the test can undermine the validity of its results. Your attorney should scrutinize the officer’s performance in administering this test, as well as your ability to perform it based on your medical history and physical characteristics.

Non-Standarized Field Sobriety Tests

You may have heard of offers dropping change on the ground and asking a suspect to pick it up, as well as the infamous “say your ABCs backwards” test. There are other non-standardized tests that are prevalent, including the finger-count test, the Rhomberg balance test, the finger-to-nose test, and the lack of convergence test. None of these tests are “standardized,” and none have ever been conclusively shown to be able to predict impairment by the NHTSA. It is important that your attorney challenges the validity of these non-standardized tests because the State will likely try to use them to prove you were under the influence, and because there is little evidence to support that claim for many of the non-standardized tests.

When You've Been Arrested For DUI

After you’ve been arrested, its advisable to remember your right to remain silent, to be compliant with the officer, and to not answer any questions. You will have your opportunity to contest the officer’s arrest decision, but you should only do so with an attorney and in court, and not in the back of a squad car. To put your best foot forward in court, contact our law firm to speak with a Knoxville DUI defense lawyer for a free review of your case.

Attorney At Law, Managing Partner

Brandon D. Fersten is an esteemed Knoxville attorney practicing DUIcriminal defense, and juvenile law. Known for his empathetic approach and commitment to his clients, he brings a record of favorable case outcomes including dismissals and not guilty verdicts at jury trials resulting in Brandon being recognized as one of the “Top 40 Under 40” in Criminal Defense, U.S. News’ Best Lawyers: “Ones to Watch,” and Super Lawyers’ “Rising Stars”. Brandon’s professional accolades, combined with his passion for justice, position him as a reliable criminal defense advocate in the East Tennessee legal landscape.