FAQ: Criminal & DUI Defense

Driving Under the Influence (DUI) refers to operating a motor vehicle while impaired by alcohol or other drugs, such that you are substantially incapable of safely operating a motor vehicle. In the State of Colorado, you are presumed to be ‘under the influence’ of alcohol when your blood alcohol level is 0.08 or higher.

Driving While Ability Impaired (DWAI) is a lesser drunk driving offense and refers to operating a motor vehicle while your ability is impaired ‘to the slightest degree’ by drugs or alcohol. In the State of Colorado, you are presumed to be ‘impaired’ when your blood alcohol level is 0.05 or higher.

This is one of the most crucial steps in the process of protecting your driving privileges!


If you fail to do this, you will almost certainly lose your driving privileges for at least 30 days. Take this piece of paper with you and go immediately to the nearest DMV office to request your hearing.

There will be a box approximately 2/3 of the way down asking if you want the officer to be present at your hearing. Check "NO". The reasoning is this...If the officer made mistakes in their reports and they are present at the hearing, they can correct those mistakes with their testimony.

After reviewing the police reports, your attorney may decide that it would help if the officer was present. In that case, the officer can be subpoenaed to the hearing.

First, do not admit to consuming alcohol. Even if you have only had two beers, the officer will likely not believe you. Frankly, that's what everyone says.

Politely inform the officer that you would like to consult with an attorney prior to answering any questions. You do have to answer questions about your identification but nothing else.

Absolutely not! These tests are not mandatory under any conditions. In fact, the officer SHOULD inform you that they are VOLUNTARY.

These tests are designed to fail the test subject and will only provide more evidence to the prosecution to use against you later.

NO! One out of five sober people who take them will be graded as a failure. Again, politely decline to perform these tests.

There are 3 recognized standard field sobriety tests (SFST's) that are routinely used in Colorado. They are the Horizontal Gaze Nystagmus (HGN), Walk and Turn, and the One Leg Stand.

You may be asked to perform other tests but they are not as widely recognized as the three listed above.

The Horizontal Gaze Nystagmus (HGN) test claims to connect blood alcohol levels with an involuntary jerking of the eyes. The officer will hold an object in front of the subject's eyes and move it back and forth and observe for this jerking.

There are any number of causes of nystagmus other than alcohol and officers have very little training in performing this test. If they are not properly qualified, this evidence may not even be admissible in court. An aggressive cross-exam of the officer is crucial in defeating this false science.

The Walk and Turn is more commonly known as walking a straight line. Unfortunately, the officer rarely actually offers the subject a straight line to walk. Instead, the subject is supposed to imagine a straight line and then walk it while following all other instructions. Again, an aggressive cross-exam of the officer is crucial to defeating this evidence.

This one is pretty self explanatory. That said, an aggressive cross-exam can defeat a poor performance on this test.

The Portable Breath Test (PBT) is a non-evidentiary test of your breath alcohol level that is usually given at the scene of your traffic stop. This test is not considered scientifically valid in Colorado courts and cannot be used against you at trial. However, even this unscientific test may be used to establish probable cause to arrest you for Driving Under the Influence of Alcohol. You are not required and SHOULD NOT perform this portable breath test. Politely decline!

In the State of Colorado, once an officer has probable cause to arrest a subject for suspicion of DUI, they can invoke the Expressed Consent Law. This law requires that you submit to chemical testing of your blood or breath to determine your blood alcohol level. If you refuse to cooperate, there will be a minimum of a one-year suspension of your Colorado driving privileges.

If you choose to take a breath test, this must be performed on a true "Breathalyzer" machine, not a portable machine that fits in the officer's hand as mentioned in the previous question. The true "Breathalyzer" test will almost certainly be done at a police station.

This question has no easy answer. Each of these tests can be attacked by an experienced DUI attorney.

The Colorado Department of Health and Environment has created a very detailed set of regulations that must be followed whenever an evidential blood or breath alcohol test is conducted.

  • Blood Test: If performed according to these regulations, the blood test is unquestionably more precise than the breath test. If you are certain that your alcohol level is not above the legal limits, then you should almost certainly choose a blood test.
    Additionally, if a blood test is chosen, two samples of blood will be drawn. The first will be analyzed by a lab of the law enforcement agency's choosing. The second sample will be saved and can be tested independently. If these results vary, and they do more often than you might think, the state's test can then be challenged in court.
  • Breath Test: All Colorado breath tests are conducted on the Intoxilyzer 9000. Again, there are a multitude of regulations that should be followed when obtaining a breath sample. If they aren't, these breath alcohol test results can be challenged in court. A detailed review of the prosecution's evidence and a request for specific records from the law enforcement agency and the Health Department may reveal substantial problems with the breath alcohol test.
    The breath test can be defeated through various legal means. You, the test subject, cannot trick the machine.

Unfortunately, Colorado law does not allow you to speak with your DUI Attorney prior to your alcohol test.

In most cases, this is not a fatal error by the police.

Your 'Miranda' rights are only necessary once you are in custody and only if the police are asking you questions. This is known as custodial interrogation. These two parts of the equation are crucial to determining if your Constitutional rights have been violated.

In most cases of simple traffic stops, you are not 'in custody' for the purposes of Miranda. Once you have been arrested, you are certainly in custody. There are situations where a court would find that you were 'in custody' prior to being restrained in handcuffs and then placed in a patrol car. These situations are extremely fact specific.

In this context, Miranda only applies to questioning by the police. If you blurt out "I'm not going to do that test because I am too drunk," or "I'm so wasted," those statements are not protected by a failure to provide a 'Miranda' warning because they were not made in response to police questioning.

  • Odor of an alcoholic beverage on your breath or clothing
  • Bloodshot, red, or watery eyes
  • Slurred speech
  • Flushed face
  • Fumbling with wallet/purse while trying to get license, registration, and proof of insurance
  • Staggering/falling when exiting your car 
  • Failure to comprehend the officer's questions
  • Swaying/instability on feet
  • Leaning on car for support
  • Being excessively silly, angry, argumentative
  • Stumbling while walking
  • Disheveled appearance 
  • Inability to follow simple directions

To minimize these signs, do the following:

  • Simplify the process of dealing with an officer as much as possible and give them as little evidence as possible.
  • Keep your vehicle registration and proof of insurance on your visor or some place where they are extremely easy to reach.
  • Roll down your window just enough to speak with the officer and enough to hand and retrieve your documents to and from the officer.
  • Speak as little as possible.


You have many Constitutional rights. Don't just give them away. There are situations where an officer can search your car and containers within it without your consent, but if they ask for your consent, they may not have that justification yet.

Don't give up your rights - call John L. Buckley, a Denver, Colorado DUI & Criminal defense attorney today!