OWI Dismissal & Defense Strategies in Wisconsin

Charged with OWI in Wisconsin? Call Chirafisi Anderson, S.C. for a free consultation or schedule one today.

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Understanding OWI Dismissals in Wisconsin

An OWI charge in Wisconsin does not automatically result in a conviction. Every OWI case – whether civil or criminal – must be supported by lawfully obtained evidence and proven under strict legal standards. When the State fails to meet those standards, the case may be dismissed or significantly reduced.

OWI dismissals most often occur when law enforcement violates constitutional protections, statutory testing requirements are not followed, or the evidence is unreliable. In other cases, dismissal occurs because prosecutors cannot prove all required elements of the offense beyond the applicable burden of proof.

At Chirafisi Anderson, S.C., we evaluate OWI cases at every stage – from the initial traffic stop through chemical testing and charging decisions – to identify legal defects that can lead to suppression, dismissal, or favorable resolution.

Learn more about our Wisconsin OWI defense practice.

OWI Laws and Constitutional Protections in Wisconsin

Wisconsin OWI cases are governed by a combination of state statutes and constitutional protections that strictly limit how evidence may be obtained and used in court. When law enforcement fails to follow these rules, critical evidence may be suppressed—often resulting in dismissal.

OWI prosecutions are primarily based on:

  • Wis. Stat. § 346.63 – Defines OWI, PAC, and restricted controlled substance offenses
  • Wis. Stat. § 343.303 – Governs preliminary breath tests (PBTs)
  • Wis. Stat. § 343.305 – Wisconsin’s implied consent and chemical testing law
  • Wis. Stat. § 343.307 – Defines prior countable offenses

In addition to statutory requirements, OWI investigations are constrained by the Fourth Amendment to the U.S. Constitution and Article I, Section 11 of the Wisconsin Constitution, which protect against unreasonable searches and seizures.

What This Means for OWI Dismissals

Evidence in an OWI case may be excluded if:

  • The traffic stop lacked reasonable suspicion or legal justification
  • The stop was unlawfully prolonged without additional cause
  • The arrest was made without probable cause
  • Chemical testing violated statutory or constitutional requirements

When suppression is granted, prosecutors are often left without admissible evidence necessary to proceed—forcing dismissal or significant charge reduction.

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Grounds for Suppression in Wisconsin OWI Cases

Unlawful or Pretextual Traffic Stop

An officer must have reasonable suspicion that a traffic or equipment violation occurred or that a crime is being committed. Simply touching the fog line or “drifting within a lane” may not be enough. If the stop lacked a lawful basis, all subsequent evidence – including field sobriety tests and chemical test results – can be suppressed.

Improper Extension of Stop

Even if the initial stop was justified, an officer cannot prolong it without new justification. For example, continuing to detain a driver after issuing a warning ticket, solely to investigate impairment, can violate the Fourth Amendment. If an officer lacked additional cause to extend the encounter, evidence obtained after that point is excluded.

Lack of Probable Cause for Arrest

After field sobriety testing, the officer must have probable cause to believe the person was operating while impaired. If the field tests were poorly administered, or if the driver showed minimal signs of impairment, the arrest itself may be unlawful. When probable cause is lacking, everything that follows the arrest — including the breath or blood test — may be suppressed.

Illegal Blood or Breath Test / Implied Consent Violations

Wisconsin’s implied consent statute (§ 343.305) governs chemical testing. Officers must correctly read the Informing the Accused form and must use approved testing instruments and procedures. When law enforcement fails to follow these statutory requirements — by skipping the observation period, using expired calibration, or omitting required warnings — test results can be excluded.

Learn more about implied consent violations on our Refusal page.

Invalid Search Warrant or Forced Blood Draw

A blood draw without voluntary consent or a valid search warrant violates constitutional protections. If the warrant lacked probable cause, was signed by an unauthorized judicial officer, or was executed improperly, the results are inadmissible. This issue often arises when officers obtain “telephonic” warrants or proceed with nonconsensual hospital draws.

Constitutionally Invalid Prior Convictions

Wisconsin counts all prior OWI-related convictions to enhance penalties. However, a prior conviction cannot be used if it was constitutionally defective — for example, if the defendant in that earlier criminal OWI case was never advised of their right to counsel. When a prior conviction is invalid, it must be excluded from penalty enhancement, reducing the charge severity.


Take Action Today – Start Your Defense

Have you been charged with an OWI in Wisconsin? Your case can be won, the evidence can be challenged. Contact Chirafisi Anderson, S.C. for a free consultation. Serving client’s across Southern and Central Wisconsin.

Trial Defense Strategies in OWI Cases

When suppression is denied or not applicable, the defense turns to challenging the accuracy, reliability, and credibility of the State’s remaining evidence. These strategies often lead to acquittals or reduced charges at trial.

The State’s burden varies:

Field Sobriety Test Reliability

Field sobriety tests (FSTs) are subjective and easily influenced by non-alcohol factors — fatigue, anxiety, medical conditions, or uneven terrain. Our attorneys expose these weaknesses by highlighting how deviations from NHTSA standards or poor testing environments produce unreliable results.

Learn more about challenging Field Sobriety Tests in Wisconsin

Breath and Blood Test Accuracy

Even “scientific” evidence can be flawed. Breath machines require precise calibration and maintenance, and blood samples must be properly stored, labeled, and analyzed by certified labs. We often work with toxicology experts to reveal contamination, mislabeling, or fermentation errors that invalidate or cast doubt on test results.

Learn more about challenging blood and breath tests in Wisconsin.

Video Evidence and Officer Credibility

Body and dash camera footage frequently contradicts written police reports. Video may show that a driver was polite, coherent, and steady — undermining the officer’s claims of impairment. Cross-examining discrepancies between footage and testimony can be one of the most effective ways to create reasonable doubt.

Medical or Physical Conditions Mimicking Impairment

Certain health conditions can produce symptoms similar to intoxication. Diabetes (hypoglycemia), neurological disorders, vertigo, or speech impediments can explain slurred speech, balance issues, or confusion. Documenting these medical factors — often through expert testimony — helps jurors understand that not every sign of impairment is caused by alcohol or drugs.

Expert Witness Testimony

Expert witnesses are vital in complex OWI cases. Toxicologists, pharmacologists, and accident reconstruction specialists can explain the limitations of chemical testing, including BAC absorption rates, retrograde extrapolation errors, and margin-of-error ranges. By demonstrating how small variances or testing delays affect results, experts often create the reasonable doubt needed for acquittal.

Localized Strategy and Jury Perception

Each county in Wisconsin handles OWI trials differently. Understanding how judges and juries in Dane, Rock, Jefferson, Columbia, Sauk, Iowa, Green, Dodge, Marquette, Juneau, and Waushara Counties evaluate credibility allows our attorneys to tailor their presentation to local expectations. We know which arguments resonate — and which do not — in each courtroom.


Why Clients Choose Chirafisi Anderson, S.C. for Your OWI Case

OWI dismissals are not accidents—they are the result of precise legal analysis, aggressive motion practice, and attorneys who know where OWI cases break down. Not every lawyer is willing or able to litigate these cases properly. We are.

At Chirafisi Anderson, S.C., we focus on identifying constitutional violations, procedural errors, and evidentiary weaknesses early—before those issues are lost or waived. Our approach is deliberate, technical, and trial-ready from day one.

Focused OWI Litigation Experience -We defend OWI cases every day across Southern and Central Wisconsin. From unlawful traffic stops to flawed chemical testing, we know how OWI cases are built—and how to dismantle them.

Proven Record of Dismissals and Suppression Wins. Our attorneys have successfully suppressed blood and breath tests, challenged unlawful arrests, and secured dismissals and charge reductions in OWI cases across multiple counties.

Recognized Legal Excellence. Our attorneys are consistently recognized by Super Lawyers® and professional organizations such as the Wisconsin Association of Criminal Defense Lawyers, reflecting our reputation for serious criminal and OWI defense.


OWI Case Results

  • OWI 2nd .15 – Dane County (May 2022)

    Result: Evidence Suppressed, Case Dismissed
  • Refusal Hearing – Dodge County (May 2022)

    Result: Refusal Dismissed
  • OWI 3rd / PAC 3rd – Dane County (February 2024)

    Result: Case Dismissed on Motion
  • OWI/PAC 2nd Offense – Dane County (June 2022)

    Result: Case Dismissed Following Motion to Dismiss
  • OWI 5th Revocation Hearing – Dane County (June 2022)

    Result: Probation Not Revoked
  • OWI / Restricted Controlled Substance – Dane County (February 2025)

    Result: Amended to Reckless Driving

View More OWI Case Results


Get Help With an OWI Dismissal or Defense Strategy

An OWI charge does not automatically mean a conviction. Many cases are dismissed or reduced when the evidence is challenged early and effectively. The outcome of your case depends on how quickly those issues are identified and litigated. The attorneys at Chirafisi Anderson, S.C. have the experience and courtroom skill to challenge unlawful stops, improper testing, and constitutional violations that undermine the State’s case.

We represent clients throughout Southern and Central Wisconsin, including Dane, Rock, Jefferson, Dodge, Columbia, Sauk, Iowa, and Green Counties.

Frequently Asked Questions About OWI Dismissals

Yes. OWI charges are dismissed when critical evidence – such as the stop, arrest, or test results – is suppressed or proven unreliable.

No. Even results well over .08 can be inaccurate if the test was administered improperly or analyzed incorrectly.

Yes. If the prosecution’s case has weaknesses, charges may be negotiated down to reckless driving or a non-OWI traffic offense.

Not always. Many OWI cases are resolved successfully through pretrial motions or strategic negotiations.

Absolutely. Each Wisconsin county has its own sentencing and plea practices, making local knowledge critical in OWI defense.