Operating with a Restricted Controlled Substance (RCS) in Wisconsin
Charged with a “Drugged Driving” or THC-Related OWI? Call Chirafisi Anderson, S.C. for a free consultation or schedule one today.
Understanding Operating with a Restricted Controlled Substance (RCS) in Wisconsin
In Wisconsin, Operating with a Restricted Controlled Substance (RCS) under Wis. Stat. § 346.63(1)(am) is treated the same as an OWI—even if you were not impaired at the time of driving.
This law makes it illegal to operate a motor vehicle with a detectable amount of certain restricted controlled substances in your blood, including Delta-9 THC (marijuana), cocaine, methamphetamine, and other Schedule I substances. Unlike alcohol-based OWI charges, RCS offenses are presence-based, not impairment-based.
At Chirafisi Anderson, S.C., we represent clients charged with THC-related and drug-based OWIs throughout Southern and Central Wisconsin, including Dane, Rock, Jefferson, Columbia, Sauk, Iowa, and Green Counties. These cases often turn on blood-testing reliability, laboratory procedures, and whether the State can meet its strict statutory burden.
Statutory Definition of Restricted Controlled Substances
Wisconsin’s Restricted Controlled Substance statute applies only to a defined category of drugs identified by law. An RCS charge is triggered when a chemical blood test detects the presence of a qualifying substance at or above the statutory threshold.
“Restricted controlled substances” include:
- Delta-9 THC (the psychoactive compound in marijuana)
- Cocaine and its metabolites
- Methamphetamine
- Other Schedule I controlled substances under Wisconsin law
The statute does not apply to all drugs or medications. Substances lawfully prescribed or administered by a medical professional are treated differently and are evaluated under Wisconsin’s impairment-based OWI statute rather than the RCS provision.
Whether a substance qualifies as “restricted” is a threshold legal issue that must be established before the State can proceed on an RCS charge.
How RCS Charges Differ from Prescription Drug OWIs
Wisconsin law treats restricted controlled substance (RCS) cases differently from OWI charges involving prescription medications. The distinction turns on presence versus impairment.
RCS charges are brought under Wis. Stat. § 346.63(1)(am) and require only proof that a restricted controlled substance was present in the driver’s blood at or above the statutory threshold. The State is not required to prove impairment.
By contrast, OWI cases involving prescription medications—such as opioids, benzodiazepines, or other lawfully prescribed drugs—are prosecuted under Wis. Stat. § 346.63(1)(a). In those cases, the State must prove that the medication actually impaired the driver’s ability to operate safely.
This distinction is critical. A driver may lawfully take prescribed medication and still face an OWI charge only if the State can establish impairment. With RCS charges, however, lawful use does not automatically prevent prosecution unless an affirmative defense applies and is properly raised.
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THC OWI in Wisconsin
The most common Restricted Controlled Substance charge in Wisconsin involves THC (marijuana). Unlike alcohol, Wisconsin law does not require proof that THC actually impaired your driving. Instead, the statute criminalizes presence, not intoxication.
What the Law Requires
Wisconsin law defines a “detectable amount” of active Delta-9 THC as 1 nanogram per milliliter (ng/mL) or greater in the blood. If a chemical blood test reports Delta-9 THC at or above that threshold, the State may pursue an RCS charge—even if there is no evidence of poor driving, failed field sobriety tests, or observable impairment.
Key legal points that matter in THC OWI cases:
- Wisconsin law defines a “detectable amount” of Delta-9 THC as 1 ng/mL or more in the blood.
- The State does not need to prove impairment — only that lab results show at least 1 ng/mL of Delta-9 THC.
- Inactive metabolites like Carboxy-THC are not prosecutable unless accompanied by active Delta-9 THC.
- A medical marijuana or prescription THC authorization may serve as an affirmative defense, but it must be properly raised and documented.
Because THC can remain detectable in the bloodstream long after intoxicating effects have worn off, drivers are often charged based on laboratory results that do not reflect impairment at the time of driving.
Why THC OWI Cases Are Heavily Litigated
THC OWI prosecutions frequently turn on:
- Whether the lab correctly distinguished active THC from inactive metabolites
- Whether testing and quantification met statutory and scientific reliability standards
These cases are fundamentally different from alcohol-based OWIs and often require careful examination of toxicology reports, laboratory procedures, and timing evidence.
What the State Must Prove to Get a Conviction for an Operating with a Restricted Controlled Substance (RCS) Charge
To convict a person of Operating with a Restricted Controlled Substance under Wis. Stat. § 346.63(1)(am), the State must prove beyond a reasonable doubt that:
- You operated a motor vehicle on a public roadway;
- At the time you operated the motor vehicle you had a detectible amount of a restricted controlled substance in your blood.
Unlike alcohol-based OWI cases, the State does not need to prove impairment. The case turns entirely on whether the blood test establishes the presence of a qualifying substance at or above the statutory threshold and whether that evidence is legally and scientifically reliable.
These elements are taken from Wisconsin Criminal Jury Instruction – Operating a Motor Vehicle with a Detectable Amount of a Restricted Controlled Substance (Wis JI 2664B).
Affirmative Defense Considerations
Wisconsin law recognizes limited affirmative defenses in RCS cases when the substance detected was lawfully prescribed or administered by a medical professional (for example, prescribed THC or methamphetamine). These defenses are not automatic. They must be raised by the defense and supported with proper documentation during pretrial proceedings.
Whether an affirmative defense applies often becomes a contested legal issue early in the case and can determine whether the charge proceeds at all.
Learn more about Operating While Intoxicated (OWI) and Operating with a Prohibited Alcohol Concentration (PAC) charges which are commonly associated with restricted controlled substance charges.
Penalties for Operating with a Restricted Controlled Substances in Wisconsin
Penalties for an RCS conviction mirror those imposed in alcohol-based OWI and PAC cases and increase based on the number of prior OWI-related offenses. Although the theory of liability differs, sentencing exposure does not.
|
Offense Level |
Classification |
Penalties |
|---|---|---|
|
1st Offense |
Civil Forfeiture |
|
|
2nd Offense |
Criminal Misdemeanor |
|
|
3rd Offense |
Criminal Misdemeanor |
|
|
4th and Subsequent |
Felony (H-E) |
|
While RCS cases are often charged based solely on laboratory results, sentencing courts do not treat them as “less serious” than alcohol-based OWIs. A conviction carries the same escalating consequences.
For a county-by-county and offense-level breakdown of how OWI sentencing actually works in practice, see our Wisconsin OWI Sentencing Guidelines page.
How We Defend Operating with a Restricted Controlled Substance (RCS) Charges
RCS cases are fundamentally evidence-driven. Because the State is not required to prove impairment, the outcome often turns on whether the prosecution can lawfully and reliably establish the presence of a restricted controlled substance at the time of operation.
At Chirafisi Anderson, S.C. our defense strategy in RCS and THC-related OWI cases focuses on the specific pressure points unique to presence-based prosecutions, including:
Why Choose Chirafisi Anderson, S.C. for an RCS or THC-Related OWI
Operating with a Restricted Controlled Substance cases are technical, evidence-driven prosecutions. Effective defense requires experience litigating blood-test reliability, laboratory analysis, and presence-based statutes—not just general OWI law. At Chirafisi Anderson, S.C., our attorneys bring:
Restricted Controlled Substance Case Results
Take Action Today – Start Your Defense
Operating with a Restricted Controlled Substance or THC-related OWI charges can carry the same consequences as an alcohol-based OWI—even when there is no evidence of impairment. These cases often turn on technical blood-test evidence and statutory interpretation.
If you’ve been charged with an RCS or THC-related OWI, contact Chirafisi Anderson, S.C. for a free consultation. We represent clients throughout Southern and Central Wisconsin, including Dane, Rock, Jefferson, Dodge, Columbia, Sauk, Iowa, and Green Counties, and focus on identifying dispositive issues early—before they define the case.