Colorado DUI Arrests - Forced Blood Draws - "I Refuse To Consent" — Colorado Criminal Lawyer Blog

Colorado DUI Arrests – Forced Blood Draws – “I Refuse To Consent.”

Colorado Warrantless Blood Draws – The Refusal to Consent: DUI Expressed Consent Law

A Guide from The Steinberg Colorado Criminal Defense Law Firm

By H. Michael Steinberg, A Colorado Criminal Defense Lawyer – Practicing Colorado Criminal Law from both sides for over 40 years.

Introduction:

“You don’t have a choice — the law says we can take your blood.” It’s a line officers use often during Colorado DUI stops, and it’s only partly true.

Colorado’s Expressed Consent Statute does require drivers to submit to testing under certain conditions, but the Colorado Supreme Court has now made clear that a conscious driver can revoke that “consent” out loud — and once that happens, the Fourth Amendment requires police to get a warrant before drawing blood.

If you’ve been told you have “no right to refuse,” or if officers drew your blood after you object, this article addresses those issues and reports and explains the law regarding:

What Colorado’s law actually requires,
What the Courts have ruled, and
Why the distinction between statutory consent and constitutional consent matters.

Colorado’s Expressed Consent Statute: The Basics

Colorado replaced its old “implied consent” law with the current Expressed Consent Statute in 1983, the same year I passed the bar exam!

It is codified at C.R.S. § 42-4-1301.1. The statute declares that anyone who drives on Colorado’s streets and highways is “deemed” to have already consented to a breath or blood test the moment a law enforcement officer has probable cause to believe they were driving under the influence, driving under the influence per se, driving while ability impaired, or underage drinking and driving.

Key Mechanics of the Statute

Probable cause is the trigger. An officer needs probable cause to believe you were driving impaired before the testing requirement kicks in — this is not a power officers can use on every stop.
You generally choose the test — for alcohol. If you’re 21 or older and suspected of alcohol impairment, you get to choose between a breath or blood test. If drug impairment is suspected instead, the officer chooses, and it will be a blood, urine, or saliva test — you don’t get input.
The clock is two hours. Whatever test is chosen, it must be completed within two hours of driving.
Unconscious or deceased drivers are tested automatically. Under C.R.S. § 42-4-1301.1(8), a person who is dead or unconscious “shall be tested” without the opportunity to refuse in the moment.
You cannot switch your choice mid-stream. Once you elect blood or breath, you’re generally locked in — unless “extraordinary circumstances” prevent that test from being completed.

What Actually Happens If You Refuse?

Refusing a chemical test in Colorado is not, by itself, a separate crime. However, it triggers a cascade of consequences that catch a lot of people off guard:

Automatic license revocation — a minimum of one year for a first refusal, with longer suspensions for subsequent refusals, under C.R.S. § 42-2-126(3)(c)(I).
The refusal itself becomes evidence against you at trial. Under C.R.S. § 42-4-1301(6)(d), a refusal is admissible at your DUI trial, and you cannot invoke the constitutional privilege against self-incrimination to keep it out.
“Persistent Drunk Driver” designation, mandatory alcohol/drug education, an ignition interlock device for at least two years after reinstatement, and SR-22 high-risk insurance requirements.
No right to speak with a lawyer first. Colorado courts have held there is no statutory right to consult an attorney before deciding whether to test.

In short: refusing while a legal option has real consequences, but it is meaningfully different from a forced, warrantless blood draw performed over your objection. That distinction is where the Fourth Amendment comes in.

A Forced Blood Draw Is a “Search” — the Constitution Doesn’t Disappear

A state legislature cannot simply define away the Fourth Amendment. Courts have repeatedly confirmed that drawing blood is a “search and seizure” that implicates the Constitution’s protection against unreasonable searches, regardless of what a state statute calls it.

Four U.S. Supreme Court Decisions Frame the Modern Rule

The Constitutional Baseline: A Blood Draw Is a Search

Start with first principles. The Fourth Amendment to the United States Constitution, and Article II, Section 7 of the Colorado Constitution, protect “the right of the people to be secure in their persons… against unreasonable searches and seizures.” The U.S. Supreme Court settled decades ago, in Schmerber v. California (1966), that drawing a person’s blood is a search of the body and a fairly intrusive one at that. That means, absent a recognized exception, police need a warrant supported by probable cause before they can stick a needle in someone’s arm to extract evidence.

Schmerber v. California (1966) — The Court first held that a warrantless, involuntary blood draw was constitutional, but only because of the specific emergency in that case: officers reasonably believed there was no time to get a warrant before evidence of intoxication would disappear as the suspect’s body metabolized the alcohol.
Missouri v. McNeely (2013) — The Court rejected the idea that the natural dissipation of blood alcohol is, by itself, always enough of an emergency to skip the warrant. Courts must look at the “totality of the circumstances” case by case; absent a real exigency, police need a warrant before drawing blood.
Birchfield v. North Dakota (2016) — The Court drew a hard line between breath and blood tests. Warrantless breath tests are minimally intrusive and can be required as a search incident to a lawful arrest. Warrantless blood tests are “significantly more intrusive,” are not justified as a search incident to arrest, and states cannot make it a crime to refuse one without a warrant.
Mitchell v. Wisconsin (2019) — For unconscious drivers, a plurality of the Court allowed warrantless blood draws based on exigent circumstances (dissipating BAC plus the pressing need to deal with an accident scene) — not because a statute had “created” consent. Notably, three justices went further, writing that “the state statute, however phrased, cannot itself create the actual and informed consent that the Fourth Amendment requires.”

That last line is the seed that grew into Colorado’s most important recent ruling on this subject.

Tarr v. People: Colorado Confirms You Have The Right To Revoke Your Consent To The Blood Test

In August 2016, Christopher Tarr struck and killed a pedestrian while driving drunk in Aurora. At the hospital, officers told him that Colorado’s Expressed Consent Statute meant his driving already counted as consent to a blood test.

Tarr responded unequivocally: “You’re not taking my blood.”

After learning the pedestrian had died, an officer told Tarr the blood would be drawn “by force, if necessary.” Tarr again refused to consent but said he would not physically resist. Police performed three blood draws roughly ten minutes apart — all before a magistrate signed a search warrant thirty-five minutes after the last draw.

The trial court and Court of Appeals both allowed the results in, relying on the earlier case People v. Hyde (2017), which had broadly stated that “there is no constitutional right to refuse a blood-alcohol test.”

On June 3, 2024, the Colorado Supreme Court reversed. Writing for the court, Justice Melissa Hart held:

“A conscious driver can revoke consent otherwise given pursuant to Colorado’s Expressed Consent Statute. When a driver revokes consent, police are generally required to obtain a warrant before executing any blood draw.”

The Court’s Reasoning Rested on Two Pillars

The legal landscape had shifted. Hyde leaned heavily on Birchfield’s approving language about implied-consent laws. But Mitchell v. Wisconsin later confirmed that a state statute doesn’t “create actual consent to all the searches [it] authorizes” — it just attaches civil penalties and evidentiary consequences to a refusal. A majority of the U.S. Supreme Court had effectively moved away from treating statutory “consent” as satisfying the Fourth Amendment on its own.
Colorado’s own statute anticipates refusal. The Expressed Consent Statute imposes license revocation and evidentiary consequences specifically because it expects some drivers to refuse. A scheme built around the possibility of refusal cannot simultaneously claim that refusal is legally meaningless.

Importantly, Tarr did not declare every blood draw taken after a revocation automatically unconstitutional. The Colorado Supreme Court sent the case back to the Court of Appeals to decide whether some other recognized exception to the warrant requirement — such as exigent circumstances — might still justify the draws.What This Means for Drivers Arrested in Colorado

For anyone facing a DUI, DWAI, vehicular assault, or vehicular homicide investigation in Colorado, a few practical points follow from this body of law:

First, driving on Colorado roads still triggers “expressed consent” as a statutory matter, and refusing a validly requested test still carries real administrative consequences: a lengthy license revocation through the DMV, independent of the criminal case’s outcome. Refusal is not a cost-free option.

Second, a clear, voiced objection to a blood draw is legally meaningful in the criminal case. After Tarr, if a conscious person unambiguously refuses, officers generally cannot simply proceed to draw blood on the theory that the statute already gave them permission. They need a warrant, or a fact-specific showing of true exigency under McNeely, not a generalized assumption that alcohol metabolizes over time.

Third, the analysis is different for unconscious drivers, and for the narrow category of serious injury and fatality cases the statute specifically addresses, where physical compulsion provisions and different case law may apply. These situations call for careful, fact-specific legal analysis.

Fourth, timing and documentation matter enormously in litigating these issues. Whether a warrant was obtained before or after the draw, exactly what was said and by whom, whether body camera or hospital records corroborate a refusal, and how quickly a magistrate was contacted can all become central to a dismissal motion.

The Bottom Line

Colorado’s Expressed Consent Statute still exists and continues to shape the administrative side of every DUI arrest in the state. But it is no longer the last word on whether a warrantless blood draw is constitutional. Under Missouri v. McNeely, Birchfield v. North Dakota, Mitchell v. Wisconsin, and now Colorado’s own Tarr v. People, a conscious driver’s real, verbal refusal carries genuine Fourth Amendment weight, and evidence obtained in violation of that right can be suppressed.

Every DUI or vehicular assault/homicide case involving a blood draw deserves a close look at exactly how that sample was obtained: what was said, whether a warrant existed, when it was signed, and whether any claimed exigency actually holds up under scrutiny. In cases where the numbers on the lab report look devastating, the constitutional question of how those numbers were obtained is often where the real defense begins.

Unconscious Drivers: The Rule That Survives

Because an unconscious person cannot verbally object, the statute’s automatic testing provision at C.R.S. § 42-4-1301.1(8) — combined with the exigent-circumstances reasoning in Mitchell v. Wisconsin — still allows a warrantless blood draw in most cases. The critical fact in Tarr was consciousness: a driver who is awake and capable of speaking can say the words that revoke consent; a driver who is unconscious cannot.

When Police Can Skip the Warrant Anyway: “Extraordinary Circumstances” and Exigent Circumstances

Two additional wrinkles matter for anyone facing a DUI or vehicular-crime charge in Colorado:

The “extraordinary circumstances” exception. Under C.R.S. § 42-4-1301.1(2)(a.5), if a driver chooses one test (say, blood) but circumstances beyond the officer’s control prevent it from being completed within the two-hour window, officers may switch to the other test. In People v. Spencer (2024 COA 75), the Colorado Court of Appeals held that medical personnel spending roughly ten minutes unable to locate a usable vein qualified as an “extraordinary or non-routine” circumstance — meaning the officer could lawfully switch Spencer to a breath test even after he had chosen blood. The statute is explicit that mere inconvenience, a heavy workload, or routine delays do not constitute extraordinary circumstances.
Exigent circumstances in vehicular-homicide and serious-injury cases. In cases like Tarr — where the case-by-case “totality of the circumstances” test from People v. Schaufele (2014 CO 43) applies — prosecutors can still try to justify a warrantless draw if they can show police genuinely lacked a realistic opportunity to get a warrant before the evidence would be lost. In Schaufele, the Colorado Supreme Court affirmed suppression because police never even attempted to get a warrant, despite having time to do so. That is a fact-specific inquiry, not a blanket rule — which is exactly why it matters to have an attorney examine the timeline in your case.

What This Means If You Are Stopped for Suspected DUI in Colorado

You will be asked to choose a test. If alcohol is suspected and you’re 21 or older, you generally control blood versus breath. Once you choose, you’re normally locked in absent extraordinary circumstances.
Refusing has real, immediate consequences — license revocation, evidentiary use at trial, and collateral penalties — even though it is not a separate crime.
You can verbally revoke consent to a blood draw, and under Tarr, officers are then generally required to get a warrant. Say so clearly and unambiguously — Tarr’s exact words, “You’re not taking my blood,” are the kind of unequivocal objection that mattered to the court.
Do not physically resist. Physical resistance can result in additional charges and creates safety risks. Tarr’s approach — clearly stating his objection but not resisting — is the model: verbal objection, not physical confrontation.
Write down exactly what was said and done, including whether you objected before or after the draw, whether a warrant was mentioned, and the timing of each event. In Tarr, the minutes between the draws and the signing of the warrant were decisive in the legal analysis.
Serious-injury and fatality cases carry higher stakes. Officers may reference “forcible blood draw” authority in these cases, but Tarr shows that even then, a clear objection generally still triggers the warrant requirement — the state doesn’t get an automatic pass just because the charges are severe.

Quick Reference: Scripts You Can Use

Situation	What to Say
Officer requests a blood or breath test after arrest	State your choice clearly: “I’ll take the breath test” or “I’ll take the blood test,” or state clearly if you are refusing.
You want to revoke consent to a blood draw	“I do not consent to a blood draw.” Say it plainly and make sure it is documented.
Officer says blood will be taken “by force”	“I do not consent, and I will not physically resist.” Do not fight the draw — object verbally only.
After the stop	Write down the officer’s name, badge number, agency, exact time of the stop, exact time of any test or draw, and exactly what was said by both sides.

Key Takeaways

Colorado’s Expressed Consent Statute (C.R.S. § 42-4-1301.1) deems every driver to have consented to alcohol or drug testing when an officer has probable cause of impaired driving — but that statutory consent is not the same thing as constitutional consent.
Refusing a test triggers license revocation and can be used as evidence against you at trial, even though refusal itself is not a separate crime.
Under Tarr v. People (2024), a conscious driver can revoke their statutory consent, and once revoked, police generally must obtain a warrant before drawing blood.
Unconscious drivers remain subject to automatic testing under People v. Hyde and C.R.S. § 42-4-1301.1(8), because they cannot verbally revoke anything.
Prosecutors can still try to justify a warrantless draw through the “extraordinary circumstances” exception (People v. Spencer) or genuine exigent circumstances (People v. Schaufele) — but these require case-specific facts, not just an officer’s say-so.

Don’t Navigate This Alone

If you were pulled over on suspicion of DUI, refused testing, or had your blood drawn after you objected, the legal timeline of what was said and when a warrant was obtained can determine whether that evidence is admissible at all. The Steinberg Colorado Criminal Defense Law Firm can review the police report, body camera footage, and warrant timestamps to determine whether your Fourth Amendment rights were respected.

Colorado Criminal Law – Colorado DUI Arrests – Forced Blood Draws – “I Refuse To Consent”

The reader is alerted that Colorado criminal law, like criminal law in every state and at the Federal level, changes constantly. The article appearing above was accurate when it was drafted, but it cannot account for changes occurring after it was uploaded.

ABOUT THE AUTHOR: H. Michael Steinberg – Email the Author at: hmsteinberg@hotmail.com

A Denver, Colorado Criminal Defense Lawyer – or call his office at 303-627-7777 during business hours – or call his cell if you cannot wait and need his immediate assistance – please call 720-220-2277.

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You should be careful to make a responsible choice when selecting a Colorado criminal defense lawyer. We encourage you to “vet” our firm. Over the last 40 years – by focusing ONLY on Colorado criminal law – H. Michael has had the necessary time to commit to the task of constantly updating himself on nearly every area of criminal law, including Colorado criminal law and procedure and trial and courtroom practice.

H. Michael works hard to get his clients the best possible results in and out of the courtroom. He has written, and continues to write, extensively on Colorado criminal law, and he hopes this article helps you in some small way.