15 Ways to Beat a Drunk Driving Case in Wisconsin (2025)

OWI, or what are commonly called "drunk driving cases," happen frequently as laws become more strict. There are, however, Wisconsin drunk driving defenses that can be used to beat a Wisconsin OWI case and successfully fight potential charges.

OWI penalties in Wisconsin can result in lengthy license revocations, expensive fines, severe jail time and even prison. In this article, OWI Defense Attorney Patrick Stangl will summarize 15 legal defenses that will help you beat an OWI/PAC (Prohibited Alcohol Concentration)/DUI/DWI charge here in Wisconsin.

If you have additional questions or would like to discuss your case with an experienced Madison OWI defense attorney, click here to complete a confidential consultation form or call Stangl Law Offices, S.C. at (800) 353-2120. 

1. Be aware of what police look for when they suspect a driver of drunk driving/OWI

Police are trained to look for certain behaviors and driving patterns that can indicate a driver might be operating under the influence, including:

• Driving late at night (around bar time).
• Erratic driving and wide turns
• Failing to use turn signals
• Failing to stop at stop signs and/or traffic lights
• Driving too far left of the center line
• Weaving between multiple lanes of traffic
• Driving without headlights on at night
• Reckless driving

Police rely on observed behaviors to justify a stop, but these behaviors can have innocent explanations. For example, weaving could be caused by road conditions, distraction, or fatigue rather than impairment.

A skilled OWI attorney can argue that the observed behaviors were not indicative of impairment. They can present alternative explanations and demonstrate inconsistencies in the officer's report or testimony.

2. Be aware of unconstitutional traffic stops

Police cannot simply pull you over on a “hunch” that you’ve done something illegal. Under the Fourth Amendment, in order for a stop to be constitutional, the officer’s suspicion must be based on: “specific articulable facts which, taken together with rational inferences from those facts, reasonably warrant that intrusion on the citizen’s liberty.” Terry v. Ohio, 392 U.S. 1, 21 (1968).  

With this in mind, it’s important to note that police are not required to rule out innocent behavior before stopping your vehicle.  

A stop is only lawful if based on specific, articulable facts suggesting a violation. Stops based solely on suspicion or profiling are unconstitutional.

I help my clients scrutinize the officer’s rationale for the stop. If the stop lacked sufficient legal basis, I can file a motion to suppress evidence, which may result in dismissal.

3. Consider whether the law enforcement officer lacked probable cause to arrest

Just because a law enforcement officer has either reasonable suspicion or probable cause to stop the vehicle does not mean he or she has sufficient legal reason to make a lawful arrest for OWI.  

Depending on what facts are known to the law enforcement officer, there may not be enough facts supporting the indication of impairment or operation/driving of the vehicle. Indications that you may have been impaired include:

• Glassy or bloodshot eyes
• Difficulty with balance
• The smell of intoxicants

The officer must have evidence justifying the belief that the driver was impaired. Misinterpretations of physical signs like red eyes or unsteady movements can lead to unlawful arrests.

Depending on the circumstances, I can challenge the officer's judgment and credibility by examining bodycam footage, witness statements, and the conditions under which observations were made.

4. Challenge the reliability of Field Sobriety Tests (FSTs)

Even the most reliable field sobriety tests (FSTs) used in Wisconsin aren’t accurate indicators of alcohol or drug impairment.  FSTs are subjective and prone to errors, particularly if administered under poor conditions like uneven ground or bad weather.

Challenging a Wisconsin Field Sobriety Test is one of many Wisconsin drunk driving defenses that can have a big impact on the outcome of your case.  

Data supporting these tests show that even when given properly, the accuracy rate for detecting impairment is only 60-77%. In Wisconsin, Field Sobriety Tests are voluntary, which means you cannot be cited for refusing them (implied consent violation). 

When reviewing my clients' cases, I often question the conditions under which the tests were conducted, highlight their voluntary nature, and argue that they are not reliable indicators of impairment.

5. Be aware that breath testing is subject to a wide variety of errors

OWI breath tests in Wisconsin can be subject to a wide variety of errors including, but not limited to:  

• Calibration errors
• Failure of maintenance tests
• Physiological and medical conditions
• Radio frequency interference

An OWI breath test doesn’t directly measure the amount of alcohol in your blood, nor does it demonstrate the alcohol concentration at the time the motor vehicle was driven or operated. These weaknesses in the test can be used to cast doubt on whether or not you were impaired at the time of arrest.   

I can request maintenance records, challenge the machine's calibration, and introduce expert testimony to dispute the results.

6. Consider medical conditions that could affect the case

Medical conditions such as acid reflux disease, heartburn, or Gastro Esophageal Reflux disease (commonly known as GERD) can establish a defense to a chemical breath test. (Conditions like GERD can lead to inaccurate breath test results by causing alcohol from the stomach to affect readings.)

Inaccurate test results can occur when an inaccurate level of alcohol is trapped in the acid that flows from the stomach into the mouth and can cause a falsely elevated BAC (blood alcohol concentration) on a breath-testing device or breathalyzer.  

I often present medical records and expert opinions to demonstrate how such conditions could have influenced the results.

7. Consider high protein diets

Isopropyl alcohol differs from ethyl alcohol (the type we consume), yet breathalyzers are unable to distinguish between them. High-protein diets can lead to ketoacidosis, resulting in ketone production.

When ketones leave the body via breath or urine, they convert into isopropyl alcohol, which may be detected by breathalyzers. Therefore, ketosis from ketogenic diets can lead to false positives on breathalyzers due to isopropyl alcohol production alcohol.

I often use scientific evidence to differentiate between alcohol types and challenge the reliability of the test results.

8. Be aware of valid defenses to a blood test that shows you are over the legal limit

Improper storage, contamination, or procedural errors can compromise blood test results. If the test tubes used for storing the blood sample are not properly activated, ethanol can accumulate in the sample. Yeast, which is quite common in the human body, can also distort blood results. Additionally, improper storage of samples can negatively impact the blood sample.

I can review the chain of custody and laboratory handling protocols to identify and exploit errors.

9. Be aware of the rising blood alcohol defense

BAC levels rise over time, meaning a test taken later may not reflect the driver’s BAC at the time of operation. If you were pulled over for an OWI shortly after finishing drinking, it’s likely that the alcohol in your system was not fully absorbed into your body.

When this is the case, your blood alcohol level continues to rise, which can lead to a falsely high breath test or blood test result.

I can use expert testimony and timing analysis to argue that the BAC at the time of driving was below the legal limit.

10. Consider your right to independently test the blood sample and computerized breath testing device

One of many Wisconsin drunk driving defenses involves your right to independently test the blood sample and/or the computerized breath testing device (the EC/IR Intoximeter I or II in Wisconsin).

The State will require you to post a bond equal to the market value of the machine, show cause to test it, and follow a list of requirements.  

I can highlight these innocent causes to challenge the prosecution’s claims.

11. Be aware that an explanation exists for the behaviors associated with OWI

Among other observations, the officer will most likely claim you had red/glossy/watery eyes, a flushed face and/or slurred speech.  

Your Wisconsin drunk driving defenses may include innocent explanations like fatigue, allergies, physical injuries, being ill or dehydrated, or having medical conditions that can mimic the symptoms the prosecutors rely upon.   

12. Be aware that poor or bad driving does not equate to OWI

In Attorney Stangl’s experience, law enforcement will always try to argue bad driving equals OWI, however this simply is not the case.  

Weaving, drifting, speeding, and even erratic vehicle movements are often not the result of being impaired by alcohol but rather simply from being distracted or inattentive.

I can examine dashcam footage or witness statements to show the driving wasn’t linked to impairment. 

13. A blood alcohol concentration (BAC) over the legal limit may not prove you violated the law

Blood alcohol test results are influenced by many different factors, not just the amount of alcohol in your body at a particular time.   Some of these factors include:  

• Medical conditions

• Inaccurate blood or breath samples

• The time you finished drinking alcohol and how much you had over a certain period of time

An extremely high BAC may also be inconsistent or discounted by an individual's level of impairment, meaning his or her physical or mental faculties.

I can compare your behavior and BAC results to show inconsistency.

14. Consider whether there is enough evidence to prove you drove or operated the motor vehicle

In order to argue that a vehicle was operated in a Wisconsin criminal case, the State must prove beyond a reasonable doubt that the individual put the vehicle into motion.  

If law enforcement cannot prove that you actually drove or operated the motor vehicle, it does not matter how intoxicated you may or may not have been.  

I can challenge assumptions about your involvement, especially in cases where no one witnessed you driving.

15. Consider using videos and dispatch tapes

Video from squad cars, booking rooms, or nearby security cameras can reveal details that contradict the prosecution’s narrative.

These videos, along with others from booking rooms or hospitals, can be effective in defending OWI cases in Wisconsin because they may show that the defendant's mental and physical faculties were not impaired.

Even if the videos show some trouble on the field sobriety tests, persuasive explanations can be provided for the client’s troubles. I have defended many cases in which the field sobriety tests have been favorable or not so favorable.  

In one recent case, my client had obvious trouble with the field sobriety tests but was nonetheless acquitted. The audio portion of the video mysteriously did not work, so neither the client nor the officer could be heard on the video.  

The tape demonstrated, however, that the officer continued to talk to the client as the client attempted to complete the various field sobriety tests. The jury found that behavior distracting and simply did not give any stock to the field sobriety tests because they could not hear what was being said. The client was found not guilty of the OWI/PAC 1st charges.

I review all available footage to highlight procedural errors or signs of non-impairment.

OWI Defense Success Story

Case Victory: Three Consecutive OWI/PAC 5th/6th Victories in One Month

Attorney Stangl of Stangl Law Offices, S.C. achieved three (3) back-to-back OWI 5th/6th victories within a one-month period in May-June 2023 thereby saving his clients from mandatory prison sentences. In State v. Shirikian, 2023 WI App. 13 the Court of Appeals held that the sentencing language for a 5th/6th OWI/PAC offense requires the sentencing court to impose a mandatory prison sentence upon conviction. Even if the sentencing court wanted to impose a non-prison sentence, they do not have the discretion or authority to do so under the current penalty structure for the offense and this decision.

In the first case Attorney Stangl successfully argued that one of his client’s prior convictions could not be counted because he was not properly advised of his right to counsel in a previous case and that the record did not demonstrate a free and voluntary waiver of his 6th amendment right to counsel. After investigating and researching the issue, Attorney Stangl brought a motion challenging the uncounseled conviction and after an evidentiary hearing the trial court agreed that the prior conviction could not be counted, thereby reducing the 5th/6th offense to non-mandatory prison charges.

Approximately 2 weeks later, in a different case, Attorney Stangl previously argued to the court that the arresting officer did not have a sufficient legal reason or probable cause to arrest his client on a 5th/6th OWI/PAC. After the evidentiary hearing and briefing by the parties the court issued a very thorough and analytical oral decision granting the defendant’s Motion to Dismiss and the case against his client was dismissed.

Within two weeks after the 2nd consecutive OWI/PAC 5th/6th victory Attorney Stangl secured his 3rd consecutive OWI/PAC 5th/6th victory within (1) one month with the dismissal by the State of charges during a preliminary hearing. At the preliminary hearing it was clear that the arresting officer testified falsely about the alleged events including his client’s performance on the field sobriety test (FST’s) when in fact his client never submitted to the FST’s. Once the State realized the major problem with the officer’s perjured testimony it moved for immediate dismissal of all the charges. His client will not be re-charged.

If you’ve been arrested or charged with OWI in Wisconsin, it’s crucial you contact an experienced Madison OWI lawyer today. Contact Attorney Patrick Stangl for a free consultation: