Aggravated DUI Attorney in Denver

What Makes a DUI “Aggravated” in Colorado

Colorado’s enhanced DUI penalties flow from C.R.S. 42-4-1301 and 42-4-1307. The term “aggravated DUI” describes the circumstances that trigger those enhanced consequences, not a separately charged crime. Which factors apply to your case determines the penalty range and shapes the defense strategy.

• BAC of 0.15% or higher: Even on a first offense, this threshold triggers the persistent drunk driver (PDD) designation under C.R.S. 42-1-102, which carries a mandatory ignition interlock device (IID) requirement of at least two years after license reinstatement.
• BAC of 0.20% or higher: A first DUI or DUI per se at this level carries a mandatory minimum 10-day county jail sentence under C.R.S. 42-4-1307, though the court may use certain sentencing alternatives where permitted.
• Prior DUI, DUI per se, or DWAI convictions: Each prior conviction escalates mandatory minimums. Two or more prior convictions require at least 60 consecutive days in county jail on a new conviction.
• A child in the vehicle: Colorado prosecutors treat a minor in the vehicle as a significant aggravating factor and may file a separate child endangerment charge alongside the DUI.
• Driving on a suspended or revoked license: When the suspension stems from a prior DUI-related matter, prosecutors may use it to seek harsher sentencing.
• DUI-related accidents: Crashes causing serious bodily injury can trigger vehicular assault under C.R.S. 18-3-205, a class 4 felony when the driver was under the influence or a class 5 felony when recklessness is the basis. Cases reaching that threshold involve separate considerations covered on our Felony DUI page.

Defense Approaches in Aggravated DUI Cases

No two aggravated DUI cases present the same vulnerabilities, but several defense categories come up consistently. We investigate each one as part of every case review.

The Traffic Stop & Arrest

The Fourth Amendment requires that a stop be based on reasonable suspicion and the arrest on probable cause. Evidence obtained through an unlawful stop may be subject to suppression. If the foundational stop falls apart, that can significantly affect the prosecution’s case.

BAC Testing Accuracy

Breathalyzer devices can produce false positives from certain medical conditions, dietary compounds, or calibration failures. Blood test results depend on proper chain of custody and laboratory handling. We request calibration records and examine the full testing process. A retrograde extrapolation defense may also apply: a toxicologist can estimate what the BAC actually was at the time of driving rather than at the time of the test, which can matter significantly when the 0.15% or 0.20% thresholds are at issue.

Field Sobriety Test Administration

Field sobriety tests must follow standardized protocols established by the National Highway Traffic Safety Administration. Deviations in how an officer administers or scores the tests can undermine the reliability of the results and can be challenged at trial or in suppression hearings.

Prior Conviction Review

Enhanced sentencing under Colorado law depends on the number and type of prior convictions. Out-of-state convictions, improperly counted offenses, or records that don’t qualify under Colorado’s statutory definitions may not support the enhanced sentencing framework. If prior convictions are miscounted, the mandatory minimum may not apply.