Do I Have to Consent to Field Sobriety Tests in SC?

Field sobriety tests (FSTs) are roadside exercises conducted by law enforcement officers during DUI traffic stops in South Carolina. Drivers who are pulled over on suspicion of driving under the influence (DUI) may be asked to submit to one or more field sobriety tests, but are they required to comply?

This article was written by South Carolina DUI attorney James R. Snell, Jr. His qualifications include being trained as a FST instructor pursuant to NHTSA qualifications. 

Under the law, drivers are not legally required to consent to field sobriety tests during a traffic stop. However, it's critical for drivers to understand and assert their rights during a traffic stop by law enforcement to avoid life-altering criminal penalties. While FST results can play a role in determining whether the driver is impaired beyond the recommended BAC limit, which is 0.08% in the state of South Carolina, they are rarely reliable as stand-alone evidence in a criminal case. Please keep in mind DUI in South Carolina is not defined by simply having a BAC at 0.08 or higher. You can be not-guilty at any level.

Keep reading to learn more about the types of field sobriety tests administered by South Carolina law enforcement in DUI stops.

What Is a Field Sobriety Test (FST)?

A field sobriety test (FST) is a physical assessment used to determine the presence of alcohol or drugs in a driver’s system. These tests may include walking heel-to-toe in a straight line, counting backward from a given number, standing with one foot elevated off the ground, and other tasks that evaluate and assess an individual's balance, coordination, cognitive ability, and understanding.

The results of field sobriety tests can be highly subjective, meaning they’re unlikely to be considered definitive evidence on their own. However, they may still be used by police officers during DUI traffic stops and can be used as valid contributing evidence in court. They can be used to establish probable cause for an arrest.

Generally, FSTs allow police officers to assess 3 categories: balance, coordination, and comprehension. By evaluating factors such as stance while performing tasks, eye movements while tracking or following objects with their eyes, and overall mental competency, officers can gain a better understanding of an individual's level of impairment.

Types of Field Sobriety Tests

There are various types of field sobriety tests used by South Carolina law enforcement in DUI stops. Under regulations enforced by the National Highway Traffic Safety Administration (NHTSA), field sobriety tests can be either standardized or non-standardized.

According to the NHTSA, standardized tests (also known as SFSTs) can be 91% accurate when all of the following conditions are true:

• All 3 standardized field sobriety tests are administered
• The law enforcement officer administers each test accurately and appropriately
• The offender doesn’t suffer from medical conditions that may interfere with the results of the SFSTs

Generally, there are 3 standardized field sobriety tests that officers may use during a DUI traffic stop:

1. Horizontal Gaze Nystagmus (HGN) Test

A horizontal gaze nystagmus (HGN) field sobriety test is conducted by police officers to determine whether or not a driver has alcohol or certain classifications of drugs in their system. HGN tests measure the involuntary jerking or twitching of the eye when looking towards the side, which can be an indication of the presence of alcohol or drugs. The jerking of the eye is called nystagmus. It does not effect vision. 

To administer this test, officers will ask drivers to keep their heads still and track an object (usually a penlight or finger) as it moves from one side of the face to the other. As the driver's eyes move, officers will look for any involuntary jerking associated with intoxication.

HGN tests are generally considered one of the more reliable physical tests for DUI evaluation due to their strong correlation with alcohol impairment levels. However, other factors can affect HGN results. Extreme fatigue, certain medications, and even inner ear issues can result in false positives on these tests.

2. Walk-and-Turn (WAT) Test

A walk-and-turn (WAT) field sobriety test is a roadside assessment used to evaluate whether a driver is under the influence of alcohol or drugs. This test requires an individual to walk heel-to-toe in a straight line for nine steps, turn around, and then walk back in the same manner.

During this physical assessment, officers make observations regarding an individual’s balance, coordination, and comprehension of instructions. To accurately evaluate a driver’s performance on this test, officers will ask them to stand with their feet together before beginning the test. They must keep both arms straight out from their body while walking and counting aloud each step taken.

3. One-Leg Stand (OLS) Test

A one-leg stand (OLS) field sobriety test is another standardized roadside assessment used to determine the presence of alcohol or drugs in a driver's system. This physical evaluation requires a driver to stand on one leg and count aloud for a period of 30 seconds.

During the OLS test, officers will look for signs of intoxication such as swaying, loss of balance, hopping, using arms for balance, or putting the raised foot down during the allotted time. The person may be asked to close their eyes while performing the test to increase the difficulty level and more accurately evaluate any impairment present. Any missteps or failure to comply with instructions can be interpreted as evidence that a driver is impaired and can use this evidence in court if they’re arrested and charged with a DUI.

Challenging Field Sobriety Test Results

For drivers charged with DUI offenses, it's imperative to consult with an experienced criminal defense attorney who understands how to challenge any unlawful evidence presented by prosecutors and police officers in court, including any inaccuracies associated with field sobriety testing and results.

5 Defenses Against FST Results in Criminal Court

There are various ways that you and a trusted criminal defense attorney can fight to dismiss FST results as unreliable evidence in your criminal case. Common defenses against FST results as reliable evidence in criminal court include:

1. The officer who administered the FST lacked proper training or qualifications.
2. The driver had a physical disability, medical issue, or medication that impacted FST test results.
3. Poor lighting conditions and/or inadequate pavement surface for balance testing invalidated the FST results.
4. Environmental factors, such as windy conditions, temperature, or humidity, affected FST results.
5. The driver was feeling overly nervous due to police presence, impairing their FST performance during the DUI traffic stop.

And Bonus reason #6 - The officer failed to correctly administer the test. For example, did the officer give improper instructions for the walk and turn, or move their hand too fast during the HGN?

Bonus reason #7 - The officer failed to actually record their actual impressions of the test. Believe it or not, many times police officers won't actually write down which indicators on which tests they observed, and won't be able to answer questions about the specific performance on cross-examination. 

Bonus reason #8 - Even a "failed" test can turn into an opportunity to demonstrate someone may not be impaired. For example, in the walk and turn there are a total of 18 heel to toe steps. A "clue" for impairment can be the feet being more than half an inch apart during the test. If the officer only knows this happened once, then that means that the steps were performed correctly 17 out of 18 times (and 17/18 = 94%, which was an "A" when I went to school!). 

Our Firm Can Fight Aggressively to Restore Your Freedom

If you’re facing DUI charges in Lexington or the surrounding area, it’s imperative to remain as calm and collected as possible when determining your next steps. First and foremost, it’s crucial to seek trusted counsel from a qualified DUI defense attorney, as they can provide invaluable insights and help you navigate the complexities of criminal court and ensure your legal rights are protected from start to finish.

Our firm has a proven track record of success representing clients throughout South Carolina in a wide range of criminal cases, from computer crimes to domestic violence offenses. Our dedicated criminal defense attorneys can carefully examine the unique circumstances of your case and determine the most effective legal strategy to employ in your defense. Reach out to the Law Office of James R. Snell, Jr., LLC to learn how we can help you avoid life-altering criminal penalties.

DUI charges carry harsh penalties if convicted. Strong representation is a must to defend your freedom. Call (803) 359-3301 to schedule a consultation.