A driver can be arrested on suspicion of DUI even when later testing raises serious questions about whether alcohol or drugs caused any impairment. A 2026 investigation found reported cases of drivers in 22 states who were arrested for DUI even though subsequent blood testing showed no alcohol or drugs. That does not mean field sobriety tests are meaningless, but it does show why an arrest based on roadside observations is not the same thing as proof of guilt.
For someone arrested in Greenville or elsewhere in South Carolina, the distinction matters. South Carolina DUI law focuses on impairment, and evidence in a DUI case can extend well beyond an officer’s interpretation of a roadside test. The Bateman Law Firm can examine the chemical testing, videos, driving evidence, medical or physical explanations, and circumstances surrounding the arrest.
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A National Investigation Found Sober Drivers Arrested for DUI
WSMV4 reported in February 2026 that its investigation identified cases in 22 states involving people arrested for DUI whose blood later tested negative for alcohol and drugs. The investigation grew out of reporting in Tennessee, where Tennessee Bureau of Investigation data showed more than 2,500 DUI arrests since 2017 involving drivers whose blood tests showed neither alcohol nor drugs.
The cases do not establish that every DUI arrest based on field observations is unreliable. They do raise a question that matters in any individual DUI prosecution:
What if behavior that looks like impairment has another explanation?
A driver might have difficulty balancing, following instructions, speaking, or moving in the manner an officer expects. Those observations can become part of the basis for an arrest. They do not independently establish what caused the behavior.
That distinction becomes especially significant when objective evidence later conflicts with the initial suspicion.
What Does South Carolina Law Actually Require for a DUI?
South Carolina’s DUI statute, S.C. Code § 56-5-2930, prohibits driving while under the influence of alcohol, drugs, a combination of drugs or substances, or alcohol combined with drugs or substances when the person’s ability to drive is materially and appreciably impaired.
That language matters.
The offense is not simply “looking impaired.” The prosecution must prove the elements of the charged offense. An officer’s observations may become evidence, but an arrest itself is not a conviction.
South Carolina also has a separate offense known as driving with an unlawful alcohol concentration, or DUAC. Section 56-5-2933 generally prohibits driving with an alcohol concentration of 0.08 percent or greater.
A case involving a person who says that he or she was completely sober may therefore require a close examination of what the officer observed, what testing showed, and whether the evidence actually establishes alcohol or drug impairment.
Why Can a Sober Person Appear Impaired?
Imagine that you are standing beside a road at night. Cars are passing nearby. You may be frightened because you have never been investigated for DUI before. An officer asks you to perform unfamiliar physical tasks while watching your movements closely.
Now add exhaustion, an old knee injury, anxiety, poor balance, neurological differences, prescription glasses, or another individual condition.
A mistake during a roadside exercise does not tell you, by itself, why the mistake occurred.
That is one of the central problems highlighted by the national reporting. One Alabama driver featured in the investigation said that he had worked a 14-hour shift and slept for about three hours. He also disclosed after his arrest that he is autistic. His blood test later showed no alcohol or drugs.
This does not mean fatigue, autism, or a medical condition automatically defeats a DUI charge. It means there may be explanations for observed behavior that have nothing to do with alcohol or drug impairment.
A defense investigation may need to separate those explanations from the conclusions reached during the traffic stop.
Field Sobriety Tests Are Evidence, Not a Chemical Test
Field sobriety tests and chemical tests answer different questions.
Roadside exercises allow an officer to observe physical performance and other behavior. Breath, blood, and urine testing can provide evidence concerning the presence or concentration of alcohol or drugs, depending on the type of test.
South Carolina law expressly recognizes several types of DUI evidence. Section 56-5-2930 permits evidence concerning field sobriety testing, the person’s driving, video recordings, breath or bodily-fluid testing, and other evidence concerning the driver’s faculties. The statute also permits evidence that may question the validity of breath or bodily-fluid test results.
That means a DUI case should not necessarily be reduced to one moment during a roadside exercise.
The full picture may matter.
Research Shows Why Field Sobriety Results Need Context
The study discussed in the national investigation provides a useful example of why context matters.
A randomized clinical trial published in JAMA Psychiatry evaluated 184 cannabis users. Of the participants, 121 received THC and 63 received a placebo. At one evaluation point, trained law enforcement officers classified 81 percent of the THC group as impaired based on field sobriety testing.
The striking finding was what happened with the placebo group.
Officers also classified 49.2 percent of the placebo group as impaired during that evaluation.
That figure should be interpreted carefully.
The study concerned the ability of field sobriety testing to identify THC-related impairment in a controlled research setting. It did not establish that 49.2 percent of all sober drivers will fail field sobriety tests, nor did it test every circumstance encountered during an ordinary South Carolina DUI investigation.
The researchers themselves concluded that the tests differentiated between the THC and placebo groups, but that the substantial overlap suggested field sobriety testing alone may be insufficient to identify THC-specific driving impairment when other indicators are absent.
For a real DUI case, that is a reason to examine the complete evidence rather than treating one roadside performance as conclusive.
What If Your Breath Test Shows 0.00?
A 0.00 breath result can be highly significant, but it does not necessarily end an investigation immediately.
A breath test is directed at alcohol. South Carolina’s implied-consent statute allows chemical testing of breath, blood, or urine for purposes of determining the presence of alcohol, drugs, or a combination of them after an arrest covered by the statute.
An officer who believes a driver is impaired by something other than alcohol may therefore investigate possible drug impairment.
This creates an important distinction:
A zero alcohol reading does not establish drug impairment, but it also does not necessarily prevent officers from investigating suspected drug impairment.
If later toxicology testing also shows no alcohol or drugs, the conflict between the original observations and the chemical evidence becomes a significant issue for the defense to examine.
A Negative Blood Test Does Not Erase the Arrest
This may be one of the most frustrating parts of the situation.
A person can know that he or she did not drink or use drugs and still be handcuffed, booked, and required to deal with a criminal accusation before laboratory evidence is available.
The eventual test result and the original arrest are two separate events.
A negative toxicology result does not travel backward in time and prevent an arrest that already occurred. It can, though, become significant evidence when evaluating whether the prosecution can prove the DUI allegation.
That is why someone facing this situation should preserve more than the laboratory report.
Video May Be Especially Valuable in a Disputed DUI Case
South Carolina law recognizes video recordings of a person’s conduct at the incident site and breath-testing site as potential evidence in DUI proceedings.
Video can allow the defense to compare what an officer wrote with what was actually recorded.
For example, an officer’s report might describe problems with balance or following instructions. Video may provide additional context:
Was the road surface level?
Were the instructions clearly given?
Did the driver appear confused about the exercise rather than intoxicated?
Could the driver’s footwear or physical condition have affected performance?
What did the driver look and sound like during the entire encounter rather than during a few selected moments?
Did the driver’s movements before and after the roadside exercises appear consistent with the officer’s description?
The answers will depend on the actual recording. The point is that the officer’s written characterization does not have to be examined in isolation.
Medical and Physical Conditions Can Matter
Not every person begins a field sobriety test with the same physical abilities.
A defense attorney may need to investigate documented conditions involving balance, coordination, mobility, vision, neurological functioning, or the ability to understand and execute instructions.
The same is true of temporary circumstances. Exhaustion, illness, injury, stress, or environmental conditions may be relevant depending on the evidence.
Suppose a driver with a documented knee condition is instructed to stand on one leg. The driver puts a foot down several times.
The prosecution may view those movements as evidence supporting impairment. The defense may contend that the physical condition provides another explanation.
Neither position should be resolved simply by attaching a label to the movement. The underlying facts and supporting evidence matter.
Chemical Evidence Should Be Examined Carefully
A blood or urine report can become one of the most significant pieces of evidence in a suspected drug DUI case, but the analysis should not necessarily stop at the final number printed on a laboratory report.
Depending on the circumstances, relevant questions may include:
- What substances were actually tested for?
- When was the sample collected in relation to the traffic stop?
- What did the laboratory identify?
- Were alcohol and drugs absent from the reported results?
- Does the prosecution rely on another substance or theory of impairment?
- How was the sample collected, stored, and tested?
- Is there video or other evidence that conflicts with the officer’s description?
South Carolina’s DUI statutes specifically contemplate challenges involving chemical testing and permit additional evidence that corroborates or questions test results.
The significance of any laboratory result depends on the facts of the case.
An Arrest Is Not Proof That the Officer’s Initial Conclusion Was Correct
Police officers sometimes must make decisions before all evidence is available. Toxicology testing may take considerably longer than the roadside investigation.
That creates a basic timing problem.
The arrest decision may be based on what the officer knows during the traffic stop. Laboratory evidence becomes available later.
If those two pictures conflict, the criminal case should be evaluated using the evidence that ultimately exists, not merely the suspicion that existed at the roadside.
South Carolina law expressly allows a defendant to challenge issues surrounding DUI testing and permits the jury to consider the totality of the evidence in determining guilt or innocence.
That can make later-developed evidence particularly significant in a case where the original theory was impairment but subsequent testing does not support the suspected source of that impairment.
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What Evidence Could Matter If You Were Sober?
If you are arrested for DUI and maintain that you had consumed no alcohol or impairing drugs, the defense may need to reconstruct the encounter rather than focusing on a single test.
Relevant evidence can include the incident video, breath-test video, chemical-test results, toxicology documentation, the officer’s reports, the reason for the original traffic stop, statements captured on video, medical records when genuinely relevant, and information concerning physical limitations that could affect roadside testing.
The timing matters as well. What happened before the stop, during the roadside investigation, at the testing location, and after the arrest can each tell a different part of the story.
A negative blood test may be powerful evidence. It should be considered together with everything else the State intends to use to prove impairment.
What the 22-State Investigation Means for South Carolina Drivers
The nationwide investigation does not establish that South Carolina has the same number or pattern of sober DUI arrests reported in Tennessee. The available reporting identified cases across 22 states, but the Tennessee figures came from Tennessee-specific data. Those numbers should not be presented as South Carolina statistics.
The broader lesson still matters here.
DUI investigations involve human observation. A roadside test is performed by a human being and interpreted by another human being. Physical characteristics or medical issues can complicate those observations. Chemical testing may later add evidence that was unavailable when the arrest occurred.
That is precisely why a DUI charge must be evaluated on its own evidence.
A poor field sobriety test does not automatically establish guilt. A DUI arrest does not establish guilt. Even a laboratory result has to be understood in the context of what was tested and the prosecution’s theory of impairment.
Arrested for DUI in South Carolina Even Though You Were Sober?
Being accused of impaired driving when you believe the evidence will show that you were sober can leave you wondering how the arrest happened in the first place.
The answer may require a careful review of the entire investigation.
The Bateman Law Firm can examine the traffic stop, field sobriety testing, video recordings, chemical testing, police reports, and other evidence relevant to a South Carolina DUI charge. Individual facts matter, and no particular piece of evidence guarantees a specific result.
If you were arrested for DUI in Greenville, Clemson, Spartanburg, or a surrounding South Carolina community, contact The Bateman Law Firm to discuss your situation. The firm offers a free consultation.
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