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Colorado DUI Laws

When a person is charged with DUI in Colorado, they are usually charged with violating two separate DUI statutes. A person can only be convicted of one DUI, but because the District Attorney can prosecute you under two different legal theories, you will often see two versions of the DUI charge on your citation.

The “Subjective” DUI Statute:
The first type of driving under the influence violation involves driving when your ability to drive has been impaired “to a substantial degree.” This version of the DUI statute has been around for a long time. In order to prosecute you under this statute, the District Attorney is not required to present any evidence of a blood result over 0.08. You could be tried and found guilty of DUI based on other facts, such as the officer’s testimony that he smelled alcohol, and observed you swerving on the road. As you can see, this type of violation uses a subjective standard to determine guilt or innocence.

The “Objective” DUI Statute:
The second type of DUI infraction is what is called “DUI Per Se.” You commit this violation automatically if your blood test shows a result over 0.08, and the test is determined by the jury to be reliable. The key phrase is “determined by the jury to be reliable.” That is where your DUI attorney comes in. There are many reasons why the blood or breath test results against you may not be reliable. Examples may include: the machine was malfunctioning, the person giving the test made mistakes, the proper testing procedure was not followed, the test was given too long after you were driving, your blood sample was mishandled – or one of several other problems. For more information, please visit our blood alcohol test page. This second type of DUI infraction uses an objective, numerical measurement to determine guilt or innocence. But it relies on a system of testing that can be unreliable.

The lesser offense of DWAI, or Driving While Ability Impaired, also uses a subjective standard to assess guilt or innocence. You will be found guilty if a jury believes that you were driving while your ability to drive was impaired by drugs or alcohol “to the slightest degree.” Notice the difference between this and the DUI statute which requires impairment to a “substantial” degree. Here again, the District Attorney does not have to introduce any blood test evidence, and could prosecute you based only on the testimony of a police officer’s observations of you.

Because the evidence against you in any DUI related case is either based on a witness’s subjective observations, or based on a BAC test where errors in the testing process are common, a skilled DUI attorney will study your case in order to challenge weaknesses in the prosecutor’s evidence.