Why Field Sobriety Tests Aren't Always Reliable — and How a Private Attorney Can Challenge Them
If you've been pulled over and asked to step out of the car to do field sobriety tests, I know how stressful that moment can be. You're standing on the side of the road, likely anxious, maybe tired, maybe even scared. The officer asks you to perform a few physical tasks — walk a straight line, balance on one leg, and follow a pen with your eyes. These tests are supposed to show whether you're impaired. But here's something I've learned after years of handling DUI cases across the country: field sobriety tests are far from perfect.
A lot of people assume that failing one or more of these tests automatically means they'll be convicted. That's not true. These tests are subjective, often influenced by the officer's opinion, and can be affected by all kinds of things that have nothing to do with alcohol or drugs. The truth is that field sobriety tests can be challenged, and I've helped many clients fight DUI charges by doing exactly that.
But doing it right takes experience, timing, and a focused legal strategy. That's where hiring a private attorney matters.
Is It Possible to Fight a DUI Charge Based on Field Sobriety Tests?
Let's talk about what these tests really are. Most officers rely on three standard tests developed by the National Highway Traffic Safety Administration: the horizontal gaze nystagmus test (where they track your eye movement), the walk-and-turn, and the one-leg stand. The officer gives instructions, watches how you perform, and then decides if you showed "clues" of impairment.
Sounds simple, right? It's not.
The problem is that these tests aren't foolproof. They require coordination, balance, and focus — things that can be affected by nerves, fatigue, medical conditions, or even what kind of shoes you're wearing. And yet, officers are trained to score you based on very specific observations. If they think you didn't follow instructions exactly or didn't stand perfectly still, they mark it as a sign you're impaired.
This is exactly where a private attorney comes in. I review the bodycam footage. I look at your background — age, health, weight, injuries — anything that could have influenced your performance. I compare how the officer gave the instructions to how they're supposed to be given. If there are errors or inconsistencies, we use them.
The Importance of Timing and Precision
Challenging field sobriety tests requires more than just saying they were unfair. We have to show exactly how and why the results can't be trusted. This starts with evidence. I send requests for video, police reports, training records, and maintenance logs the moment I take on a case. I don't wait for court dates or for the prosecutor to decide what to hand over.
In many cases, we find problems — like the officer skipping key instructions, exaggerating what they saw, or performing the tests on an uneven surface. I've even had cases where the officer wrote that the client failed the test, but the video showed otherwise.
These are the details that matter, and they don't get uncovered without a close, early look. Public defenders, while they may care about their clients, often have too many cases to give each one this kind of attention. As a private attorney, I take the time to investigate the details that can change everything.
Medical Issues, Weather, and Other Factors
Let's be real — not everyone can stand perfectly still or walk heel to toe, even on a good day. I've had clients with back issues, knee surgeries, balance problems, and neurological conditions who struggled with the tests not because they were impaired, but because they physically couldn't perform them well.
Even things like high heels, gravel shoulders, poor lighting, or passing cars can throw you off. But unless someone points those things out to the court, the officer's opinion often goes unchallenged.
That's why I ask every client about their health, their footwear, the road conditions, and how they felt that night. I connect those answers with the video and the officer's report. And if something doesn't match, I use it to cast doubt on the field tests.
Officers Make Mistakes — And It Matters
Police officers are human. They get tired. They miss steps. They forget training. I've seen officers who rushed through instructions, skipped demonstration steps, or gave misleading cues. Those mistakes can make the entire test unreliable.
But unless someone with legal training points out those problems, they go unnoticed. The officer's report often carries a lot of weight in court. That's why I challenge it line by line. I compare it with the video, question how the test was administered, and look for anything that weakens the state's case.
This is one of the biggest benefits of hiring a private lawyer. We're not just reacting to the evidence — we're actively breaking it down, finding holes, and building arguments that put pressure on the prosecutor to reconsider the charge.
Prosecutors Don't Always Want to Fight These Cases
When we find clear issues with field sobriety tests, it puts prosecutors in a tough spot. They know juries may not believe the test results if we show they are unreliable. They also know judges may throw out the arrest if the test was the only basis for it.
When that happens, prosecutors often back off. They may offer a reduced charge or even dismiss the case outright. But that only happens if we've done the work to show why the test can't be trusted.
Without a private attorney, those arguments may never be made. You're left hoping the system gives you a break. That's not a strategy. You need someone who's working for you from the beginning, digging into the details, and building a real defense.
Field Sobriety Tests Alone Shouldn't Decide Your Case
I can't stress this enough: field sobriety tests are not proof beyond a reasonable doubt. They are indicators, not hard science. Prosecutors and officers may act like they're the final word, but they're not.
When I defend someone, I challenge the foundation of the case. If the field tests were flawed, if the officer didn't follow the rules, or if there's reasonable doubt about the observations, we use that to push back hard.
You have the right to defend yourself. And you have the right to do it with someone who takes your case seriously and looks at it from every angle. That's what I do, and that's what a private attorney offers that you may not get anywhere else.
Field Sobreity Test Frequently Asked Questions
Can field sobriety tests be used as the main reason for a DUI arrest?
Yes, officers often rely on field sobriety tests to support an arrest for DUI. But that doesn't mean the results are always reliable. If the officer makes mistakes during the test or ignores important factors like medical conditions or road conditions, the test results can be challenged.
Are field sobriety tests required by law?
In most states that use the term DUI, field sobriety tests are voluntary. You can legally refuse them without immediate penalties in many cases. However, refusing may still lead to an arrest based on other observations. It's important to speak with an attorney as soon as possible to understand how refusal might affect your case.
How do officers decide if someone fails a field sobriety test?
Officers are trained to look for specific "clues" during each test — things like losing balance, stepping off the line, or not following instructions exactly. But those clues are often open to interpretation. What one officer sees as a failure, another might overlook. That's why reviewing the test carefully is so important.
Can I fight a DUI charge if I fail the field sobriety tests but pass the breath test?
Yes, that situation comes up more often than people think. Some officers rely heavily on field tests even when chemical tests show a low result. If the field tests were flawed or your behavior didn't match impairment, we can use that to challenge the case.
What if I have a medical condition that affects balance or coordination?
Medical conditions can absolutely affect how you perform on field sobriety tests. Conditions like vertigo, knee injuries, or neurological disorders can mimic signs of impairment. When I build a defense, I look at your medical history and use that to question the officer's conclusions.
Do courts believe field sobriety tests are always accurate?
Not always. Courts know these tests have limits. If we can show that the test wasn't done properly or that the results are unreliable, the court may disregard them. But it takes work and a clear presentation to make that argument stick.
Is video from the stop important in challenging field sobriety tests?
Yes, video can be one of the strongest tools we have. It shows how the officer gave instructions, how you performed, and what the conditions were like. I request this footage right away because it often reveals details the police report leaves out.
Can a private attorney really make a difference in these cases?
Absolutely. A private attorney can spend the time needed to study the video, question the officer's training, examine the conditions, and look for flaws in how the test was handled. That level of attention can be the difference between a conviction and a dismissal.
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Musca Law, P.A. has a team of experienced criminal defense attorneys dedicated to defending people charged with a criminal or traffic offense. We are available 24/7/365 at 1-888-484-5057 for your FREE consultation.