Can I Challenge Field Sobriety Tests in a Wisconsin OWI Stop?

 Posted on July 31, 2026 in DUI/OWI

You can challenge field sobriety tests in a Wisconsin OWI stop. These tests are far from perfect. They rely on an officer's judgment, not hard science. Attorney Paul Bucher spent 20 years as the Waukesha County District Attorney. This gives him rare insight into how these tests get used to build a case against you.

If you’re facing an OWI in 2026, our Milwaukee County, WI criminal defense lawyer can look at whether the tests in your case were done the right way. He may also help you challenge them.

What Are Field Sobriety Tests and Why Do Officers Use Them in OWI Cases?

Field sobriety tests are physical and mental exercises officers use during a traffic stop. They help the officer guess whether a driver might be impaired. These typically include the walk-and-turn test, the one-leg stand, and the horizontal gaze nystagmus test, which checks for a certain kind of eye movement. Officers use these tests to build probable cause for an arrest. But the results depend a lot on how carefully the test was given and how the officer read your performance. This leaves a lot of room for error and challenge.

What Factors Can Affect Your Performance on Field Sobriety Tests?

Many things that have nothing to do with alcohol or drugs can affect how someone does on a field sobriety test. These commonly include:

• Poor lighting or uneven pavement at the location of the stop
• Bad weather, like rain, wind, or cold temperatures
• Medical conditions that affect balance, coordination, or vision
• Nervousness or anxiety during a stressful police encounter
• Physical limitations unrelated to impairment, like an old injury
• Bad footwear, like high heels

These factors can affect your performance no matter whether you've had a drink. Because of this, an attorney can look at whether any of these things applied to your specific stop.

Does Wisconsin Law Require Officers to Follow Specific Testing Steps?

Field sobriety tests are generally based on standards set by the National Highway Traffic Safety Administration. Officers are trained to give them a certain way. Maybe an officer skipped a step. This could mean giving unclear instructions, testing you on a bad surface, or scoring the test wrong. Any of these can give you real grounds to challenge the results. Wisconsin courts take these steps seriously, since skipping them can make an officer's conclusions less reliable.

How Does Wisconsin Law Define OWI?

Wisconsin addresses operating while intoxicated under Wisconsin Statute Section 346.63. This law makes it illegal to drive a vehicle while under the influence of alcohol, drugs, or with too much alcohol in your system.

Field sobriety test results often serve as key evidence backing up an officer's decision to arrest someone under this law. Because of this, successfully challenging these tests can weaken the state's case against you quite a bit.

Can You Challenge an Officer's Training or Certification?

Officers must get specific training on how to give and read field sobriety tests. Maybe an officer lacks proper certification. Maybe they haven't had recent refresher training. Maybe they have a history of giving these tests wrong in other cases. Any of this can matter when you're challenging the results in your specific case.

Can Video Evidence Help Challenge Field Sobriety Test Results?

Dashcam or body camera footage from your stop can show important details about how the tests actually went. This includes the officer's instructions, the conditions at the scene, and how you actually did compared to what the officer wrote in their report. Sometimes video contradicts what an officer says happened. It might show you had pretty steady balance, even though the report says otherwise. This kind of mismatch can become a powerful tool in fighting your case.

Contact Our Waukesha County OWI Defense Attorney for a Free Consultation

Facing an OWI charge based on field sobriety test results doesn't mean your case is a lost cause. These tests carry a lot of room for error and personal judgment calls. Attorney Paul E. Bucher was elected twice as President of the Statewide District Attorneys Association. He also served on dozens of statewide task forces addressing violent crime. He has handled some of the most high-profile and complicated cases in Wisconsin.

Contact Bucher Law Group, LLC at 262-446-9222 to talk to our Milwaukee County, WI criminal defense lawyer today.