Wisconsin's two OWI theories: impairment vs. per-se
Wisconsin Statute § 346.63(1) defines two parallel theories of operating-while-intoxicated:
- § 346.63(1)(a) - OWI: "Under the influence of an intoxicant, a controlled substance, a controlled substance analog or any combination of [same]... or under the influence of any other drug to a degree which renders him or her incapable of safely driving." Impairment-based; the state must prove the driver was actually impaired.
- § 346.63(1)(b) - PAC: "The person has a prohibited alcohol concentration." Per-se; the state must prove the BAC was at or above the threshold. No impairment needs to be shown.
A third theory, § 346.63(1)(am), covers operating with any detectable amount of a restricted controlled substance. The three are routinely charged together as alternative theories from a single incident.
Single-conviction rule (§ 346.63(1)(c))
Under Wis. Stat. § 346.63(1)(c): "If the person is found guilty of any combination of par. (a), (am), or (b) for acts arising out of the same incident or occurrence, there shall be a single conviction for purposes of sentencing and for purposes of counting convictions under ss. 343.30 (1q) and 343.305." A defendant cannot be convicted twice for the same incident even when multiple subsections are charged.
PAC thresholds by driver category
| Driver category | Statute | PAC threshold |
|---|---|---|
| Standard adult (≤ 2 priors) | § 340.01(46m)(a) | 0.08 |
| Repeat offender (3+ priors) OR subject to § 343.301 IID order | § 340.01(46m)(c) | more than 0.02 |
| Commercial-vehicle operator | § 346.63(5)(a) | 0.04 |
| Under-21 driver (absolute sobriety) | § 346.63(2m) | more than 0.0 but not more than 0.08 |
Why the defense strategy differs between OWI and PAC
Even though the penalty structure is identical, the defenses are different because the elements are different.
To defeat an OWI charge under (1)(a), the defense attacks the impairment evidence:
- Field-sobriety test administration and NHTSA-protocol compliance
- Officer observations: vehicle in motion, personal contact, pre-arrest screening
- Body-cam and dash-cam contradictions of the officer's narrative
- Independent witness testimony on driving behavior
To defeat a PAC charge under (1)(b), the defense attacks the chemical-test result:
- 20-minute observation period violations before breath testing
- Intoximeter EC/IR II calibration logs and maintenance records
- Mouth-alcohol contamination (belching, regurgitation, recent dental work)
- Blood draw by unqualified personnel or without proper consent under § 343.305
- Bullcoming v. New Mexico (564 U.S. 647) Confrontation Clause issues when the lab analyst is unavailable for cross-examination
- Chain-of-custody gaps in blood-tube handling between draw and lab
A motion that suppresses the chemical test collapses the PAC charge entirely. The OWI charge may survive if other impairment evidence is strong; if both fall, the entire case dismisses.
The reduced .02 threshold catches a lot of repeat offenders by surprise
Under § 340.01(46m)(c), a driver with three or more prior convictions or revocations counted under § 343.307(1) is subject to a "more than 0.02" PAC threshold. That applies whether or not the driver is currently under an IID order. For practical purposes, a single 12-ounce beer can put a repeat-offender driver over the threshold within an hour of consumption. Many third- or fourth-offense defendants are charged after a single drink at dinner because they did not realize the threshold had dropped.
How common is a Wisconsin PAC charge?
Wisconsin's Department of Transportation publishes annual conviction counts in its "Traffic Convictions Entered on Driver Record" report. The BAC-prohibited and PAC categories are tracked separately from the OWI category and from each other, but in practice the same incident often generates multiple records.
- 16,122 BAC-prohibited convictions in 2024 (Wisconsin DOT). 17,516 in 2023. 10-year total: 167,604.
- 3,943 PAC convictions (code 212) in 2024 (Wisconsin DOT). 3,703 in 2023.
- 25,066 OWI convictions in 2024 (Wisconsin DOT) for context: every BAC-prohibited and PAC charge is typically a sub-component of the larger OWI prosecution count.
- 18,645 total OWI + counted-offense convictions statewide in 2023 per Wisconsin Legislative Fiscal Bureau Informational Paper #62 (January 2025). Down 22.4% from 2014.
Sources: WI DOT Traffic Convictions 10-year summary · WI LFB Informational Paper #62, January 2025
The PAC charge is the chemical-test charge. Defending it means defending the test. We file preservation requests for the Intoximeter calibration logs, the 20-minute observation video, and the blood-draw chain of custody on day one. Call (262) 632-5000 24/7 for Racine, Kenosha, and Walworth County OWI / PAC defense.
