DUI Per Se in Colorado – Driving with Excessive Alcohol Content

Under Colorado law, you can be charged with DUI Per Se if your blood alcohol content (BAC) is 0.08 or higher within two hours of driving.

This offense focuses solely on the chemical test result — even if you appeared to be driving normally.

In other words, the State does not have to prove you were “drunk,” only that your BAC reached 0.08 or above within that two-hour window.

The Legal Definition

C.R.S. § 42-4-1301(2)(a) makes it a misdemeanor to:

“Drive a motor vehicle when the person’s BAC is 0.08 or more at the time of driving or within two hours after driving.”

If evidence suggests you drank after driving but before the test, you may raise an affirmative defense — forcing the prosecution to prove beyond a reasonable doubt that your BAC reached 0.08 before you stopped driving.

How DUI Per Se Differs from Regular DUI

Most DUI arrests in Colorado actually result in two separate charges:

1. DUI (Driving Under the Influence) — based on observed impairment, and
2. DUI Per Se (Driving with Excessive Alcohol Content) — based solely on a BAC of 0.08 or higher within two hours of driving.

Under C.R.S. § 42-4-1301(5), the prosecution does not have to choose between them.

A court or jury may convict a person of both DUI and DUI Per Se for the same incident — but the sentences must run concurrently, not consecutively, and they remain separate convictions.

Penalties for DUI Per Se

A conviction for DUI Per Se carries the same penalties as a standard DUI:

• Jail: 5 days to 1 year in county jail
• Fines: $600 to $1,000, plus court costs and surcharges
• License Revocation: 9 months for a first offense (longer for subsequent offenses)
• Alcohol Education and Therapy: Required by law
• Community Service: 48–96 hours
• Ignition Interlock: Mandatory upon early reinstatement

Defenses to DUI Per Se Charges

These cases often hinge on the accuracy and reliability of the chemical test.

Defense strategies may include:

• Questioning the two-hour rule: Was the test actually performed within two hours of driving?
• Challenging BAC accuracy: Improper calibration, maintenance, or operator error can invalidate results.
• Medical and physiological factors: GERD, diabetes, and certain diets can artificially elevate breath readings.
• Blood test issues: Fermentation, storage, or chain-of-custody errors can compromise results.
• Alcohol after driving: If you consumed alcohol after you stopped driving and before testing, you may raise an affirmative defense under the statute.

Why Experience Matters

Prosecutors treat DUI Per Se cases as straightforward — but they often aren’t.

An experienced DUI defense lawyer knows how to:

• Subpoena calibration and maintenance records
• Cross-examine officers about collection procedures
• Retest blood samples through independent labs
• Identify violations of the two-hour rule and related protocols

With more than 20 years of experience defending DUI cases across Adams, Arapahoe, Jefferson, Weld, and Denver, I know how to challenge the state’s evidence and protect your license and your future.

Call Me Today

If you’ve been charged with DUI Per Se in Colorado, don’t wait.

The DMV case starts immediately after your arrest — and you only have 7 days to request a hearing to protect your license.

📞 Call me, Monte Robbins, at 303-355-5148 for a free consultation.

You’ll speak directly with me — not a junior associate or call screener.