What Are Field Sobriety Tests in South Carolina?

In most of the DUI or DUAC cases that our Charleston DUI lawyers handle, Field Sobriety Testing (FST) is the primary method a police officer uses to establish probable cause. Most officers use the three (3) “standardized” tests prescribed by the National Highway Traffic Safety Administration (NHTSA). To administer these FSTs, officers receive extensive training. However, in our experience, officers often don’t follow their training and deviate from NHTSA standards when administering these tests.

Notably, a version of the officers’ training manual expressly states that “validation of the FST’s applies only when the tests are administered in the prescribed standardized manner.” The earlier manual further states that “if any one of the standard field sobriety test elements is changed, the validity is compromised.” SLED has since updated the manual to remove these warnings, but the principles still apply.

Nevertheless, we often see officers change the elements and deviate from the prescribed standardized manner, yet still arrest drivers investigated for DUI based on these test results. So what are the field sobriety tests used in South Carolina, do you have to take them, and can the results be challenged in court?

Quick Answer: Field sobriety tests in South Carolina are roadside exercises that officers use to look for signs of impairment during a DUI investigation. Most officers use the three standardized tests: horizontal gaze nystagmus, walk-and-turn, and one-leg stand. Refusing a field sobriety test does not constitute disobeying a police command, but the officer can note the refusal, and a DUI lawyer can challenge tests that were not given or scored according to the officer’s training.

What Are Field Sobriety Tests?

Field sobriety tests are roadside exercises that officers use to look for signs of impairment. The three tests in the standardized field sobriety test battery, developed through NHTSA-funded research, are the horizontal gaze nystagmus test, the walk-and-turn test, and the one-leg stand test. Officers in South Carolina are trained to give these tests in a specific way and to score them by counting “clues” of impairment.

The following table summarizes the three standardized field sobriety tests and how officers are trained to score them:

Field sobriety tests are investigative tools, not medical examinations. An officer’s conclusion that you showed clues of impairment can support an arrest, but it is not the final word on whether the State can prove DUI in court.

What Is the Horizontal Gaze Nystagmus Test?

The Horizontal Gaze Nystagmus (“HGN”) test, also known as the “pen test,” requires the officer to move a pen or other object back and forth across the suspect’s line of sight in a particular manner. The officer then looks for an involuntary jerking of the eye called nystagmus. According to NHTSA, nystagmus indicates that a person may be impaired. The officer looks for three clues in each eye, for a total of six:

• The eye cannot follow the object smoothly.
• The eye jerks distinctly when it is held at the far edge of its range.
• The jerking begins before the eye reaches about 45 degrees.

The HGN test requires the officer to move the pen at an approximate speed. However, officers regularly move the pen faster than their training allows. This deviation, among other factors, allows DUI defense attorneys to challenge the test in court.

This test is also technical. Lighting, flashing emergency lights, passing traffic, fatigue, head injuries, and certain medical conditions can all affect the result.

What Is the Walk and Turn Test?

The next test is called the Walk and Turn (“WAT”). During this test, the officer gives a series of instructions to the suspect as to how to perform the test, which includes standing with one foot in front of the other while the instructions are given, walking 9 heel-to-toe steps in one direction along a real or imaginary line, making a precise type of turn, and walking 9 steps back in the same manner while counting out loud and keeping the arms at the sides.

These instructions are numerous and a lot to take in, even for completely sober drivers. In addition, the test requires the suspect to make unnatural body movements, since walking heel to toe is not how people ordinarily walk. Officers are encouraged to use actual lines, such as painted lines in a parking lot, when possible, although many officers ignore this suggestion.

The officer watches for clues such as losing balance during the instructions, starting too soon, stopping while walking, missing heel-to-toe, stepping off the line, using the arms for balance, making an improper turn, or taking the wrong number of steps. Notably, many of these clues involve the suspect’s failure to follow all of the instructions with exact precision. Ironically, the officers do not follow the instructions from their training, despite being formally trained and having administered these tests dozens, if not hundreds, of times.

The officers do not give the suspect credit for minor mishaps, even though the suspect is extremely nervous and hears a series of confusing instructions quickly before the test. Also, NHTSA standards require the officer to “limit [his] movement which may distract the suspect during the test.” Officers regularly ignore this instruction and walk beside the suspect, in the suspect’s periphery.

Many sober people have trouble with this exercise, especially on a sloped shoulder, loose gravel, or wet pavement, or while wearing boots, heels, or sandals.

What Is the One Leg Stand Test?

The third “standardized” test is the One Leg Stand (“OLS”). During this test, the suspect must raise one foot about 6 inches off the ground, keeping the raised foot parallel to the ground. The suspect must then count, “one one-thousand, two one-thousand,” and so on until the officer tells him to stop. Little does the suspect know that the officer is actually checking whether he can hold his foot up for thirty full seconds.

If the suspect knew about the thirty-second requirement, he might prepare his balance better or refuse the test altogether. On top of that, police officers often deviate from the protocol and do not give the suspect all of the instructions required by their training. For example, police sometimes do not advise the suspect to “keep his feet together” while the officer explains and demonstrates the test.

The officer looks for swaying, using the arms for balance, hopping, and putting the foot down. A person with a knee or back injury, an inner ear problem, a physical disability, excess weight, or advanced age can struggle with this test without being impaired at all.

Why Can Field Sobriety Tests Be Unreliable?

Field sobriety tests work best when given on a dry, level, well-lit surface, with clear instructions, to someone with no physical condition that would affect balance or eye movement. Roadside conditions rarely match that description. Rain, wind, traffic noise, poor lighting, flashing patrol-car lights, and nervousness can all affect performance.

Officers also tend to rely on standard phrases and report checkboxes. Red, watery eyes can come from allergies or fatigue. A person may speak carefully because they are nervous. An odor of alcohol does not show how much a person drank or prove that the person was impaired while driving. You can read more about how officers describe impairment in our article on the signs of intoxication in a South Carolina DUI.

Do You Have to Take Field Sobriety Tests in South Carolina?

Roadside balance and eye tests differ from the chemical breath test, which officers can request after an arrest under South Carolina’s implied consent law. South Carolina law states that refusing a field sobriety test does not constitute disobeying a police command. You can politely ask the officer whether the roadside exercises are voluntary and decide without becoming confrontational.

That choice involves trade-offs. Performing the tests can give the officer more material to describe as signs of impairment. Declining the tests can still be described in the officer’s report and does not prevent an arrest if the officer believes other facts establish probable cause. No roadside choice automatically ends a DUI investigation.

Whatever you decide, stay calm and follow the officer’s lawful directions. Provide your driver’s license, registration, and proof of insurance when asked. You may politely decline to answer questions about where you have been or what you have had to drink, but never lie to the officer about your identity or anything else.

Is a Roadside Breath Test a Field Sobriety Test?

No. An officer may ask a driver to blow into a handheld breath device at the roadside. That preliminary test differs from field sobriety tests and from the formal breath test administered after an arrest under South Carolina’s implied consent law. If an officer asks you to take a breath test, ask which test they want before you decide. Refusing the formal breath test after an arrest carries its own consequences, which we explain in our article on what happens if you refuse a breath test in South Carolina.

Do Field Sobriety Tests Have to Be Recorded?

South Carolina Code § 56-5-2953 requires officers to video record certain parts of a DUI arrest. The video at the incident site generally must begin no later than when the officer turns on the blue lights and must include any field sobriety tests administered. If the officer fails to follow these requirements, the remedy depends on the defect and whether a statutory exception applies; a recording violation does not automatically require dismissal of the charge.

The video is often the most important piece of evidence in a DUI case. It may show whether the officer gave understandable instructions, chose a suitable place for the balance tests, and accurately described your performance. It can also show facts that never made it into the report, such as heavy traffic, uneven pavement, a calm and clear conversation, or a driver explaining an injury. You can learn more in our article on videotaping DUI arrests in South Carolina.

Can Improperly Conducted Field Sobriety Tests Be Challenged in Court?

Some courts have excluded field sobriety test results when officers did not administer the tests in accordance with applicable standards. In other cases, the court may admit the evidence and allow the DUI defense lawyer to argue to the jurors about the officer’s deviations. When jurors see the tests, they may see the suspect step off the line, put his foot down, or not make the turn exactly as the officer wanted, so it is important to explain how the tests were administered and what else may have affected the suspect’s performance.

In 2000, the Ohio Supreme Court issued an opinion in State v. Homan. Specifically, the court held that to use field sobriety test results as evidence of probable cause to arrest, the officer must strictly comply with standardized testing procedures. Ohio later changed its law to permit field sobriety test results at trial upon proof of substantial compliance with applicable testing standards. Ohio law does not govern South Carolina DUI cases. As it stands in South Carolina, good DUI defense lawyers will continue to review field sobriety tests with a fine-toothed comb and challenge officers to administer them correctly.

What Does a DUI Lawyer Look For in Field Sobriety Tests?

The police report is only one account of what happened. A careful review of the field sobriety tests in a DUI case asks questions such as:

• Why did the officer stop the vehicle, and did the officer have a lawful basis to extend the stop and ask you to perform field sobriety tests?
• Were the field sobriety tests administered and scored as the officer was trained?
• Were the surface, lighting, and location suitable for the tests?
• Did you have a medical condition, injury, or physical limitation that affected your performance?
• Does the video show what the officer wrote in the report?
• Did the officer have probable cause to arrest you?

If you were stopped at a roadblock, our article on whether DUI checkpoints are legal in South Carolina explains the rules officers must follow. For a broader look at what can happen after an arrest, see our article on DUI penalties in South Carolina.

If you’ve been charged with DUI in Charleston, SC, our Charleston DUI defense lawyers at Futeral & Nelson, LLC can help protect your rights. Contact us today to schedule a consultation.