The DUI Stop and the Test
C.R.S. 42-4-1301.1 — a choice of blood or breath, a sample within two hours, and a refusal that can be used at trial
A driver in Colorado is required to take and complete a test of breath or blood for alcohol when an officer with probable cause requests it. A person who elects blood or breath may not change the choice, and failing to complete it counts as a refusal.
Who handles this in Colorado: legal aid programs and the state offices, listed in the Colorado directory.
- The person cooperates so the sample can be obtained within two hours of driving.
- For drugs, the test may be of blood, saliva or urine, also within two hours.
- A roadside preliminary screening test may be refused, and it does not substitute for the required test.
A refusal at trial. If the person refuses and later stands trial for DUI or DWAI, the refusal is admissible as evidence, and the privilege against self incrimination does not keep it out.
Testing is also limited by the Fourth Amendment. The Supreme Court of the United States has held that a breath test may be taken without a warrant as part of a lawful arrest for drunk driving and a blood test may not; that a driver may not be criminally punished for refusing a blood test where no warrant was obtained; and that the natural fall of alcohol in the blood does not by itself create an emergency excusing a warrant in every case, which is decided case by case on all the circumstances. Those holdings are a floor: a state's own constitution and statutes can give more protection than they do, never less.
Sources for this section (4)
- C.R.S. 42-4-1301.1 — Expressed consent for the taking of blood, breath, urine, or saliva sample - testing - rules - definition
- C.R.S. 42-4-1301 — Driving under the influence - driving while impaired - driving with excessive alcoholic content - definitions - penalties
- Birchfield v. North Dakota, 579 U.S. 438 (2016) — A breath test may be taken incident to arrest, a blood draw needs a warrant
- Missouri v. McNeely, 569 U.S. 141 (2013) — The natural fall of blood alcohol is not by itself an emergency justifying a warrantless draw
Legal information, not legal advice. Verified as of October 2026. Applying it to a particular situation is the work of a licensed Colorado attorney.