DUI Defense

A Colorado DUI case can affect nearly every part of a person’s life, from jail exposure and fines to driver’s license loss, ignition interlock requirements, insurance costs, employment problems, and professional licensing consequences. Colorado’s DUI laws are broad enough to cover alcohol, marijuana, prescription medication, illegal drugs, and combinations of substances, and prosecutors often pursue these cases aggressively even when the stop, testing, or evidence of impairment is open to challenge. Under Colorado law, the main DUI statute is C.R.S. § 42-4-1301, and it covers DUI, DUI per se, DWAI, drug-related DUI, marijuana-based impairment allegations, and felony DUI based on prior convictions.

These cases arise in many different forms. A person may be accused after a traffic stop, a crash, a roadside investigation, a blood draw after a hospital visit, a refusal allegation, a high-BAC reading, or an administrative DMV action that proceeds separately from the criminal case. In some situations, the case also involves a child passenger, a CDL holder, a licensed professional, or allegations that the DUI caused injury. Colorado DMV materials also make clear that the DUI process has two distinct tracks: the criminal court case and the administrative license case, which move separately and can both affect the driver.

Colorado DUI Defense Attorney

A DUI charge in Colorado is never just about one number on a breath test or one officer’s opinion at the side of the road. These cases often turn on the legality of the stop, the reliability of chemical testing, whether the officer actually observed impairment, whether the test was obtained within the required time, whether the person was truly impaired at the time of driving, and whether the prosecution can prove every statutory element beyond a reasonable doubt. In drug-related or marijuana-related cases, those issues can become even more complicated.

At the Law Office of Matthew A. Martin, P.C., we understand that DUI cases often involve rushed conclusions, flawed testing assumptions, body camera footage that does not always match the written report, and administrative license consequences that can begin before the criminal case is resolved. Matthew Martin carefully reviews the stop, the arrest, the chemical testing, the DMV issues, and the prosecution’s theory of impairment in order to expose weaknesses and fight for the strongest possible defense. We work to protect our clients not only from criminal penalties, but also from the long-term consequences that follow a DUI conviction in Colorado.

If you or someone you love has been charged with DUI in Colorado, call (303) 725-0017 to schedule your free consultation today.

Overview of DUI Charges in Denver, Colorado

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Definition of DUI Under Colorado Law

Colorado recognizes several different impaired-driving offenses under C.R.S. § 42-4-1301. DUI means driving a motor vehicle or vehicle under the influence of alcohol, one or more drugs, or a combination of both alcohol and one or more drugs. DUI per se means driving when the person’s BAC is 0.08 or more at the time of driving or within two hours after driving, subject to Colorado’s statutory framework. DWAI means driving while ability impaired by alcohol or by one or more drugs, or by a combination of alcohol and one or more drugs, to the slightest degree so that the person is less able than ordinarily prudent to exercise clear judgment, sufficient physical control, or due care in the safe operation of a vehicle.

Colorado law also expressly recognizes drug-related DUI theories. The statute states that “one or more drugs” includes any drug as defined by Colorado law, any controlled substance, and inhaled glue, aerosol, or other toxic vapors. The statute further states that the fact a person is entitled to use one or more drugs under Colorado law, including medical or retail marijuana, does not itself constitute a defense to a DUI or DWAI charge. That makes it possible for prosecutors to pursue alcohol DUI, drug DUI, marijuana DUI, combined-substance DUI, DUI per se, or DWAI depending on the evidence they believe they can prove.

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Types of Colorado DUI Charges and Related DUI Cases

DUI — Standard DUI is charged when prosecutors allege that alcohol, drugs, or both impaired the person to the point that they were under the influence while driving. This is often the charge filed when officers rely on driving behavior, admissions, physical observations, roadside tests, and chemical testing together. Unlike DUI per se, the state is not limited to a BAC-based theory and may instead argue that the totality of the circumstances proves impairment.

DUI Per Se — DUI per se focuses on the chemical test result rather than observational proof alone. Under Colorado law, the core threshold is a BAC of 0.08 or more at the time of driving or within two hours after driving, though the statute also allows the defense to raise certain post-driving alcohol-consumption issues if supported by credible evidence. These cases often turn on timing, machine reliability, blood-draw procedure, and whether the number can truly be tied to the defendant’s BAC at the relevant legal time.

DWAI — DWAI is a separate and lesser offense than DUI, but it is still a serious criminal charge with real jail exposure, fines, probation, and license consequences. Colorado defines DWAI very broadly, requiring only that the person’s ability to operate safely was impaired to the slightest degree. In practice, that lower threshold gives prosecutors substantial flexibility and makes DWAI a common charge in cases where the evidence may be too weak or too disputed for a full DUI conviction.

Drug DUI and Marijuana DUI — Colorado allows DUI and DWAI prosecutions based on alcohol, drugs, or a combination of both. In marijuana DUI cases, the state often relies on blood-test evidence, driving conduct, officer observations, and statements by the accused. These cases can be especially difficult because the existence of a substance in the body does not always resolve the real issue: whether the person was impaired at the time of driving in the way the statute requires.

High BAC DUI — Colorado’s penalty statute creates enhanced consequences for a first DUI or DUI per se where the person’s BAC was 0.20 or more at the time of driving or within two hours after driving. High-BAC cases also often trigger more severe treatment demands, stronger sentencing arguments from prosecutors, and more serious concerns from the court. Even when the charge title remains DUI or DUI per se, the BAC level can significantly change the penalty landscape.

First, Second, Third, and Felony DUI — Colorado’s DUI laws become much more severe as a person accumulates qualifying priors. First, second, and third offenses each carry their own escalating sentencing structure under C.R.S. § 42-4-1307. DUI, DUI per se, and DWAI become class 4 felonies if the new violation occurred after three or more qualifying prior convictions arising out of separate and distinct criminal episodes, or certain prior vehicular homicide or vehicular assault convictions.

DUI With a Child in the Vehicle — A DUI case involving a child passenger can become much more serious because prosecutors may also file child abuse charges under C.R.S. § 18-6-401. That means a DUI with a child present may involve both the underlying DUI or DWAI charge and a separate child-abuse theory based on alleged endangerment. These cases often carry much greater family, custody, and reputational consequences than a standard DUI case.

DUI Causing Injury — A DUI case becomes much more serious if the prosecution alleges the impaired driving caused injury to another person. In some situations, what might have started as a standard misdemeanor DUI investigation can become a vehicular assault case or another far more serious prosecution. The existence of an injury allegation often changes both the stakes of the case and the aggressiveness of the prosecutor’s approach.

CDL DUI — Commercial drivers face DUI risks beyond the ordinary Colorado driver. Colorado law specifically provides that a person who holds a CDL or drives a commercial motor vehicle is subject to the general DUI penalties as well as separate commercial-driver disciplinary consequences. Colorado’s administrative licensing statute also recognizes “excess BAC CDL” consequences, and Colorado law places commercial drivers out of service if they operate a commercial motor vehicle while having any alcohol in their system or refuse the required test while driving a commercial vehicle.

Licensed Professionals Charged With DUI — A DUI conviction or even unresolved criminal history can create additional risks for licensed professionals and applicants in regulated occupations. Colorado’s Division of Professions and Occupations explains that criminal history may be considered in licensing review when it is directly related to the profession or where public-safety concerns are implicated. That does not mean every DUI automatically destroys a professional license, but it does mean licensed professionals often face a second layer of consequences beyond court and DMV.

Boating While Intoxicated — Colorado criminalizes operating a vessel under the influence of alcohol, drugs, or both. The boating statute uses familiar 0.08 alcohol thresholds and recognizes alcohol- and drug-based impairment theories. For someone under investigation in a broader substance-related traffic or recreation context, this can be an important related charge to understand.

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Penalties for DUI in Colorado

Colorado DUI penalties depend on the exact charge, the defendant’s prior record, the BAC level in some cases, and whether the offense is misdemeanor or felony level. The court process and DMV process are separate, so a person may face criminal penalties in court and independent license consequences through the Department of Revenue. Colorado DMV expressly states that the administrative path and the court path operate independently, and a court dismissal does not automatically eliminate DMV consequences.

First-Offense DUI — A first DUI or DUI per se conviction carries 5 days to 1 year in county jail, a fine of $600 to $1,000, and 48 to 96 hours of useful public service. The court may also impose up to 2 years of probation. If the defendant’s BAC was 0.20 or more, the jail range increases to 10 days to 1 year.

First-Offense DWAI — A first DWAI carries 2 days to 180 days in county jail, a fine of $200 to $500, and 24 to 48 hours of useful public service. If the person’s BAC was 0.20 or more, the statute increases exposure to 10 days to 1 year in jail, a fine of $600 to $1,500, 48 to 120 hours of useful public service, and at least 2 years of probation.

Second-Offense DUI / DUI Per Se / DWAI — If the defendant has one qualifying prior at sentencing, Colorado law provides 10 consecutive days to 1 year in county jail, a fine of $600 to $1,500, 48 to 120 hours of useful public service, and at least 2 years of probation. Colorado also restricts some sentencing alternatives during the mandatory minimum period in repeat-offense situations.

Third-Offense DUI / DUI Per Se / DWAI — If the defendant has two or more qualifying priors at sentencing, the range becomes 60 consecutive days to 1 year in county jail, a fine of $600 to $1,500, 48 to 120 hours of useful public service, and at least 2 years of probation. Third DUI cases are treated much more seriously by courts and prosecutors, even when they remain misdemeanor cases.

Felony DUI / DUI Per Se / DWAI — DUI, DUI per se, and DWAI become class 4 felonies when the new offense occurred after three or more qualifying prior convictions arising out of separate and distinct criminal episodes, or qualifying vehicular homicide or vehicular assault convictions. A class 4 felony generally carries 2 to 6 years in prison, a possible fine of $2,000 to $500,000, and 3 years of mandatory parole. If probation is granted instead of prison, the statute still requires substantial jail exposure and other mandatory conditions.

High BAC / Refusal Consequences — Colorado DMV states that a chemical test showing a BAC of 0.15 results in a Persistent Drunk Driver designation, and that a refusal also results in that designation. The DMV says those designations affect reinstatement requirements and often require treatment and ignition interlock. The criminal case and DMV process may both treat high BAC and refusal as serious aggravating features.

Cost of a DUI Conviction — The cost of a Colorado DUI case is not limited to fines. The total burden may include jail, probation, alcohol and drug education, treatment, useful public service, reinstatement fees, SR-22 insurance, ignition interlock costs, towing, bond, lost work, higher insurance premiums, and professional or employment consequences. Colorado DMV also lists reinstatement requirements that may include interlock, SR-22 insurance, reinstatement fees, and alcohol education or therapy sessions.

Ignition Interlock Devices – Colorado’s ignition interlock program is designed to prevent someone from starting or operating a vehicle after drinking. DMV explains that the device requires a breath sample before the engine will start and then requires additional samples while driving. If the device detects elevated alcohol, the vehicle will not start. That makes ignition interlock not just a reinstatement tool, but also an ongoing compliance condition that can shape a person’s daily life after a DUI case.

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Types of DUI Testing and Evidence in Colorado

Field Sobriety Tests — Field sobriety tests are typically used by officers as roadside investigative tools to build probable cause and support their observations of alleged impairment. These tests are not the same as a chemical test under Colorado’s express consent law, and they are frequently challenged based on roadside conditions, medical issues, footwear, weather, fatigue, instruction errors, and officer interpretation. In many cases, the real battle is not whether the officer “administered” a field test, but whether the results actually show intoxication rather than stress, nervousness, or a physical limitation.

Roadside Breath Testing — Colorado DMV states that the roadside breath test, often called a preliminary breath test or PBT, does not satisfy the chemical testing requirement under the state’s express consent process. Instead, for alcohol cases, the required test is the Intoxilyzer breath test administered by the officer or a blood test taken at the officer’s request. That distinction matters because officers and prosecutors may still use roadside testing as part of the investigation, but it does not replace the statutory chemical test requirement.

Blood Testing (BAC) — Colorado’s express consent statute requires drivers to take and complete a breath or blood test for alcohol when law enforcement has the necessary grounds, and it allows blood, saliva, and urine testing where drug impairment is at issue. Blood testing is often central in DUI per se, drug DUI, marijuana DUI, and combined-substance cases because it may be the primary quantitative evidence the prosecution relies on. These cases often involve challenges to timing, collection procedure, chain of custody, and whether the result actually proves impairment at the time of driving.

Urine Analysis — Colorado’s expressed consent statute specifically refers to blood, saliva, and urine testing when drug content is at issue and a law enforcement officer has probable cause to believe the person was driving under the influence or impaired by one or more drugs or a combination of alcohol and drugs. While blood evidence is often more central in many modern DUI prosecutions, urine analysis remains part of the statutory testing structure. Defense counsel may challenge whether the chosen testing method was appropriate, timely, and scientifically helpful to the actual issue in dispute.

Roadside Drug Tests and Drug-Impairment Investigations — In drug-related DUI cases, officers often rely on a mix of observations, questioning, driving behavior, field tests, and later chemical testing rather than a simple roadside number equivalent to an alcohol breath result. Colorado’s statute authorizes chemical testing for blood, saliva, and urine when officers have probable cause to believe a person was driving under the influence of one or more drugs or a combination of alcohol and drugs. That means so-called roadside drug cases often depend heavily on officer interpretation and later toxicology rather than one immediate roadside reading.

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Express Consent Laws, Refusal, and DMV Hearings

Colorado’s express consent law is found in C.R.S. § 42-4-1301.1. It states that any person who drives a motor vehicle upon Colorado streets and highways is deemed to have expressed consent to the statute’s testing provisions. For alcohol investigations, the person is generally required to take and complete a breath or blood test when law enforcement has the required grounds. For drug investigations, the statute authorizes blood, saliva, and urine testing when the officer has probable cause to believe the person was driving under the influence or impaired by drugs or a combination of alcohol and drugs.

Colorado DMV explains that refusal to cooperate with the chemical testing process results in administrative consequences even apart from the criminal case. For violations on or after January 1, 2014, DMV states that a first refusal results in a one-year revocation and a Persistent Drunk Driver designation. DMV also emphasizes that neither the roadside breath test nor a later test at a detox facility satisfies the statutory duty to cooperate.

DMV hearings are separate from the criminal case. Colorado DMV states that the administrative hearing must generally be requested within seven days of the DUI arrest if a breath test was refused or given at the stop, or within seven days of receiving blood test results where blood testing controls the timing. DMV also states that the administrative proceeding determines license consequences even if the court case is later dismissed. That separation makes early defense planning especially important in any Colorado DUI case.

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DUI License Revocation, Reinstatement, and Ignition Interlock

A DUI arrest can trigger license revocation or restraint through the DMV administrative process, and those consequences are distinct from what happens in court. Colorado’s administrative statute, C.R.S. § 42-2-126, governs revocation based on administrative determination, including refusal-based cases and certain BAC-based actions. The DMV hearing process can also address constitutional validity of the officer’s initial contact and arrest under the administrative framework.

Colorado DMV states that reinstatement requirements may include an ignition interlock device, SR-22 insurance, a reinstatement fee, and alcohol education or therapy. DMV also states that high BAC of 0.15 and refusal both lead to a Persistent Drunk Driver designation, which affects reinstatement requirements. If the person has multiple alcohol violations or refusals, the wait time for early reinstatement with interlock may be increased.

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CDL DUI and Licensed Professionals Charged With DUI

CDL holders face a much more fragile legal and professional situation when accused of DUI. Colorado law provides that CDL holders and commercial drivers are subject not only to ordinary DUI consequences but also to separate commercial disciplinary actions. Colorado law also states that a person driving a commercial motor vehicle with any alcohol in their system or refusing a test while driving a commercial motor vehicle shall be placed out of service, and the administrative statute separately recognizes “excess BAC CDL” issues. For someone whose livelihood depends on a CDL, these cases can threaten both ordinary driving privileges and the ability to continue working in commercial transportation.

Licensed professionals may face another layer of exposure. Colorado’s Division of Professions and Occupations explains that criminal history may be considered in licensing decisions when it substantially relates to the ability to safely or competently practice or creates an unreasonable risk to public safety. That does not mean every DUI automatically results in discipline or denial, but it does mean that doctors, nurses, teachers, attorneys, financial professionals, and many other licensed individuals may face consequences beyond the courtroom and DMV.

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Defenses to DUI Charges in Colorado

No Actual Impairment — The prosecution must prove the charged offense, not merely suspicious driving or a traffic stop. In DUI and DWAI cases, that means the state must establish impairment under the statutory definition, whether by alcohol, drugs, or both. A defense may focus on the absence of reliable signs of impairment, alternate explanations for officer observations, and whether the total evidence actually proves the person was under the influence or impaired to the slightest degree as charged.

Unlawful Stop or Unlawful Arrest — If the officer lacked reasonable suspicion for the stop or probable cause for the arrest, the defense may challenge the legality of the seizure and seek suppression of evidence. Colorado’s administrative statute itself recognizes that a driver may challenge the constitutional and statutory validity of the officer’s initial contact and arrest in the DMV context. These issues can therefore matter in both the criminal and administrative sides of the case.

Chemical Test Problems — Breath, blood, urine, or saliva evidence may be vulnerable to timing challenges, collection problems, machine reliability issues, contamination arguments, chain-of-custody concerns, or interpretation disputes. Colorado’s DUI statute expressly allows a defendant in a DUI per se case to offer evidence that testing may have been defective or inaccurate. In many cases, the prosecution’s strongest-seeming evidence is only as good as the procedure behind it.

Weak Proof in Drug or Marijuana Cases — Drug DUI cases can be especially open to challenge because the presence of a drug is not always the same thing as actual impairment at the time of driving. Marijuana and prescription-medication cases often involve disputed issues of timing, tolerance, lawful use, medical condition, and the relationship between a lab result and actual driving impairment. Defense counsel works to prevent the state from substituting toxicology shorthand for real proof.

Field Sobriety and Observation Challenges — Field sobriety tests and roadside observations are highly dependent on the officer’s training, the conditions of administration, and subjective interpretation. Physical limitations, nervousness, fatigue, injury, footwear, weather, lighting, roadside slope, and emotional stress can all influence performance. These weaknesses are often central to cross-examination and trial strategy.

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Role of a Colorado Criminal Defense Attorney

A Colorado DUI defense attorney does much more than stand next to the client at court. Counsel must analyze the stop, the arrest, body camera footage, chemical testing, administrative deadlines, and the prosecution’s legal theory under the exact statute charged. Because the DMV track and the court track are separate, a defense attorney must also think strategically about both at the same time rather than treating the case as one single proceeding.

An attorney also helps determine whether the case is really about DUI, DUI per se, DWAI, drug impairment, high BAC, refusal, felony enhancement, or some combination of overlapping theories. That matters because each theory creates different evidentiary vulnerabilities and different defense opportunities. In many cases, the key to the defense is forcing the prosecution to prove precisely what it charged instead of relying on the general stigma associated with the word “DUI.”

Where a CDL, licensed occupation, child passenger, or injury allegation is involved, the attorney’s role becomes even more important because the collateral consequences may be just as damaging as the sentence itself. A strong defense strategy should therefore address criminal penalties, license consequences, professional risk, and future record impact all at once.

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Key Elements the Prosecution Must Prove

For a DUI charge under C.R.S. § 42-4-1301, the prosecution must prove beyond a reasonable doubt that the defendant drove a motor vehicle or vehicle in Colorado and was under the influence of alcohol, one or more drugs, or both. For a DWAI charge, the prosecution must prove driving plus impairment to the slightest degree. For DUI per se, the prosecution must prove the statutorily prohibited BAC threshold under the statute’s framework. For felony DUI treatment, the prosecution must also prove the qualifying prior convictions required by law.

That means the state must prove the exact version of the offense it charged, not simply show that the officer suspected intoxication. Failure to prove any required element requires acquittal on that charge, even in a case where the accusation itself sounds serious. This is one reason careful statutory analysis is so important in every Colorado DUI defense.

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Frequently Asked Questions

What is the difference between DUI and DWAI in Colorado?
 DUI requires proof that the person was under the influence, while DWAI requires proof that the person’s ability was impaired to the slightest degree. DWAI is still serious, but it is a distinct and lesser offense under the statute.

Is DUI per se based only on the BAC number?
 It is a BAC-based offense under Colorado law, but the defense may still challenge timing, test accuracy, procedure, and whether the statutory requirements were actually met. A test result does not make the case immune from attack.

Do I lose my license automatically after a DUI arrest?
 Not necessarily automatically, but you face a separate DMV process that can revoke or restrain your driving privileges even if the court case is dismissed. DMV states that you generally have only seven days to request a hearing in many DUI situations.

What happens if I refuse chemical testing?
 Colorado DMV states that a first refusal results in a one-year revocation and a Persistent Drunk Driver designation for violations on or after January 1, 2014. Refusal can also create major issues in the criminal case.

Can I be charged with DUI for marijuana or prescription medication?
 Yes. Colorado’s DUI statute expressly covers one or more drugs and combinations of alcohol and drugs. Legal entitlement to use a substance does not automatically prevent a DUI prosecution.

Does a DUI affect CDL holders differently?
 Yes. Colorado law imposes separate commercial-driver disciplinary consequences, and CDL holders can face out-of-service orders and other commercial privilege problems beyond the ordinary DUI case.

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Additional Resources

Colorado Revised Statutes § 42-4-1301 — This is the core Colorado DUI statute defining DUI, DUI per se, DWAI, drug-related DUI theories, marijuana-related DUI issues, underage alcohol provisions, and felony DUI structure. It is the starting point for understanding how Colorado classifies and charges impaired-driving cases.

Colorado Revised Statutes § 42-4-1307 — This is the main penalty statute for Colorado traffic offenses involving alcohol and drugs. It sets out the sentencing ranges for first, second, third, and felony DUI-related convictions and is essential for understanding jail, fine, probation, and useful public service exposure.

Colorado Revised Statutes § 42-4-1301.1 — This is Colorado’s expressed consent statute. It explains the state’s rules for blood, breath, saliva, and urine testing in DUI and DWAI investigations and is critical in refusal and chemical-testing cases.

Colorado DMV – The DUI Process / Administrative Process / Alcohol DUI / Ignition Interlock — Colorado DMV’s DUI pages explain the separate administrative path, hearing deadlines, revocation issues, reinstatement requirements, interlock, Persistent Drunk Driver rules, and treatment requirements. These resources are especially important because the DMV process can affect driving privileges even when the court case turns out differently.

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Denver DUI Defense Attorney, CO

If you think you can’t afford top-tier criminal defense services, think again: we will work with you to establish a payment plan that fits within your budget. After all, you could be facing fees and penalties that could amount to more than what you’ll end up paying us for your defense.

Remember that the Colorado criminal justice system has all the cards stacked in their favor until you hire an attorney. Only then do you have a fighting chance.

When you’re ready to take action to protect your livelihood in the face of a DUI, DWAI, or vehicular homicide charge, we’re ready to work with you. To schedule your initial consultation, contact the Law Office of Matthew A. Martin, PC today by calling (303) 731-4517.

We know this is a stressful, upsetting, and tumultuous time. It can be difficult to think clearly in light of everything that’s going on. But hiring Matthew Martin to represent your interests in court might be the single best decision you can make right now.

Matthew Martin represents clients throughout the state of Colorado, including the city of Denver and the surrounding areas in the Front Range region including:

  • Brighton in Adams County
  • Centennial and Littleton in Arapahoe County
  • Boulder and Longmont in Boulder County
  • Broomfield in Broomfield County
  • Castle Rock in Douglas County
  • Golden in Jefferson County

Take control of your future and make the call at 303.725.0017. We look forward to hearing from you.

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