This page was written, edited, reviewed & approved by Justin C. Olsinski following our comprehensive editorial guidelines. Justin C. Olsinski, the Founding Partner, has 16+ years of legal experience as an attorney.
During a traffic stop in North Carolina, a police officer may ask you to step out of your car to perform field sobriety tests. These tests help officers decide whether they have probable cause to arrest you for driving while impaired. Field sobriety tests are a major tool used in DWI cases, but they are not perfect. Data from the National Highway Traffic Safety Administration shows that even under ideal conditions, standardized field sobriety tests are only 65–77% accurate in detecting impairment. At The Olsinski Law Firm, we explain how these tests work, their limits, and how a defense attorney can challenge this evidence in court.
Field sobriety tests are physical and mental exercises used by law enforcement during a DUI stop. They help an officer look for signs of drunk driving, such as slurred speech, bloodshot eyes, or trouble following instructions. These tests divide a driver’s attention and test motor skills and cognitive skills. They are subjective, and officers often rely on personal judgment instead of clear measurements. We help clients understand that FSTs alone do not prove blood alcohol content or guilt.
Officers may use several roadside tests, but only three are approved as standardized field sobriety tests by the National Highway Traffic Safety Administration. These tests are used across Charlotte, Mecklenburg County, and the rest of North Carolina. Each test has strict procedures under N.C. Gen. Stat. § 20-16.3, and any mistake by the officer can affect the results. At The Olsinski Law Firm, we study officer training, test procedures, and environmental factors to find errors. These problems can weaken the evidence, and our defense team uses them in court.
The Horizontal Gaze Nystagmus test is also known as the “pen test.” The police officer moves a small object, like a pen or finger, side to side in front of the driver’s eyes. The test checks for involuntary jerking of the eye, which alcohol can make worse. Common clues include lack of smooth pursuit, distinct jerking at maximum deviation, and early onset of jerking. We review medical conditions and officer errors that may affect the results.
The Walk-and-Turn Test is a heel-to-toe exercise used to measure balance and divided attention. The officer asks the driver to follow a line, take a set number of steps, turn, and return the same way. Clues include stepping off the line, taking the wrong number of steps, or using arms for balance. Environmental factors, such as uneven pavement, can create problems. We use these issues to challenge the officer’s conclusions.
In the One-Leg Stand Test, the driver must raise one foot and hold it off the ground while counting aloud. This test measures balance, focus, and the ability to follow instructions during roadside tests. Common clues include swaying, hopping, or placing the foot on the ground before the test ends. Medical conditions, such as inner-ear or neurological imbalance, can affect the outcome. We examine these issues closely during criminal defense.
Field sobriety testing may seem official, but the results are far from perfect. These tests rely on human judgment, and small errors can result in unfair DWI charges. A law enforcement officer may rely on standardized tests, yet real-world conditions make them unreliable. At The Olsinski Law Firm, we explain how these problems weaken the state’s case. We use this knowledge to build legal strategies and defend clients in driving under the influence and driving while intoxicated cases.
Many outside factors can affect field sobriety tests. These include:
A person may struggle with these tests for reasons unrelated to alcohol or drugs. Common issues include:
In North Carolina, you can politely refuse field sobriety tests during a DUI stop. This refusal does not result in a separate license suspension or revocation, as with a chemical test refusal under the implied consent law. However, the law enforcement officer may still arrest you if they see other signs of impairment. These signs may include slurred speech, bloodshot eyes, or trouble following instructions. We help clients understand when an FST refusal is the best legal option.
Field sobriety tests give officers evidence they claim supports probable cause for arrest. When a driver is pulled over, the officer uses roadside tests to decide whether the driver is impaired. If they see enough clues, they may arrest you and request a breath test or a blood test. These clues can be verbal responses, trouble with counting exercises, or poor balance. We evaluate each clue to challenge the basis of the arrest.
An arrest based on field sobriety tests does not mean a conviction. Our DWI lawyer team knows how subjective these tests are and how officer experience varies widely. As criminal defense attorneys, we use courtroom experience and a strong defense style to weaken this evidence. We study the defendant's videotape, review roadside conditions, and gather details the officer may have overlooked. These steps give us many legal options to defend your case.
We question the officer about their training, officer experience, and how they followed test procedures. We ask about lighting, surface conditions, and whether they provided proper instructions during the walk-and-turn test or the one-leg-stand test. We also ask whether they considered medical conditions or cognitive limits that affect performance. If the officer failed to follow North Carolina General Statute requirements, we use that failure as part of our defense. Strong cross-examination can expose major flaws in the arrest.
Many things can cause poor performance on roadside tests. We present evidence of:
No. You may refuse all field sobriety tests without facing an automatic driver’s license penalty. These tests are voluntary, even during a traffic stop. We explain this right to every client who contacts us for legal advice.
An officer may still arrest you for a criminal offense based on other signs, like slurred speech or the smell of alcohol. Still, you deny the state a major piece of evidence. This helps us build a stronger DUI defense.
Yes, but the state’s case becomes weaker. Without test results, prosecutors must rely on dashcam video, officer statements, and chemical testing, such as a breathalyzer or blood analysis. We focus on weakening each piece of that evidence.
No. Tell the officer about your medical issue and politely decline physical tests like the finger-to-nose touch test or Rhomberg balance test. Attempting them may produce clues the officer will use against you. We explain these risks to clients who were pulled over.
No. They can be wrong due to medical limits, bad weather, distractions, nervousness, or poor instruction from the officer. Even standardized tests can fail if the officer does not follow proper steps. We challenge these problems in court.
Stay calm and do not answer detailed questions without an attorney. You still have Fifth Amendment rights, so avoid statements before hearing your Miranda warnings. Contact a DWI lawyer at our firm right away. Our team will review the breath sample, blood sample, and chemical analysis to prepare your defense.
Field sobriety tests are subjective and often misread, even when a driver is sober. A poor performance does not prove your blood alcohol concentration or guilt, and many arrests depend on unreliable roadside clues. At The Olsinski Law Firm, we have the courtroom experience and skill needed to challenge this evidence. We also review chemical testing from Intoxilyzer machines, infrared spectroscopy, and blood analysis done at a booking center or hospital.
If you were arrested for driving under the influence in Mecklenburg County or nearby areas, reach out now. Use our contact form or call us directly to schedule your free case evaluation. We will fight to protect your rights and your future.
Mr. Olsinski founded his criminal defense practice in Charlotte, NC, in January 2010. He has successfully defended cases ranging from B1 Felony First Degree Sex Offenses/First Degree Murder to Misdemeanor marijuana charges.
"*" indicates required fields
