If you have been arrested for DUI or DWAI in Colorado and you want to fight the case against you, your attorney will have to consider all of the possible defenses to your case. If there is a good potential defense to the case, your drunk driving defense attorney may be able to persuade the prosecutor to dismiss or at least reduce the charges that you are asked to plead guilty to. The same defenses may be available to help you to avoid the revocation of your driving privileges.
Like any criminal offense, a DUI charge has "elements" that must be proven before a jury can find you guilty. In Colorado, the prosecutor must prove
1) That you were driving a vehicle,
2) After you had consumed drugs or alcohol, and
3) You had consumed enough drugs or alcohol that your ability to drive was impaired to a substantial degree (DUI), or to a slight degree (DWAI).
A winning defense to these charges can be anything that effectively challenges the proof regarding one or more of these elements, and therefore prevents the prosecutor from establishing their case against you. Other defenses include preventing the prosecutor from introducing some or all of the evidence against you in the first place.
You cannot be found guilty of driving under the influence, in any form, if you were not driving the vehicle. In most cases, the officer makes an arrest after pulling the driver over, in which case, there is no defense based on the idea that you were not driving. However, you may still be charged with DUI even in situations where you were not directly observed to be driving by the officer. The police can use circumstantial evidence to show that you were driving the vehicle recently, though this may make proving the case more difficult for the prosecutor in Denver.
If the arresting officer did not have the legal authority to stop your' vehicle, or did not have probable cause to arrest you, then the judge may rule that the evidence against you cannot be admitted at trial. This will effect the outcome of your case, even in the event the case is resolved before jury trial. Excluding evidence in this way can make it difficult, if not impossible, for the district attorney to prove you guilty. For example, if the breath test results and the officer's statements against you are suppressed by the judge, the prosecutor may not be able to offer enough proof that you were under the influence to win the case.
The Denver police officers must have reasonable suspicion to pull you over, and then must have probable cause to arrest you. If you are pulled over without there being adequate reasonable suspicion, then any evidence that the officer obtained after that should be suppressed by the judge, and therefore cannot be used by the prosecutor. Your attorney will be able to examine the evidence to determine if the officer had probable cause at the time of the arrest. If the officer did not, then a skilled attorney may file a motion to suppress the illegal arrest and all of the evidence that came as a result of it.
Should your case go to trial, you will be allowed to call witnesses to testify on behalf of your defense case. If such a witness is not willing to come to court voluntarily, they can be subpoenaed to come to your trial. A witness may be asked to testify to the fact that you did not drink before you drove, that you appeared to be sober, that you didn't stop at a stop sign because you were distracted by a conversation – not because you were under the influence.
Explanations for Your Appearance or Actions
The officer in your case may claim that you appeared to have blood-shot eyes, or were slow retrieving your license and registration, etc. Your defense case may present information to counter the police officer's claims. For example, a doctor may testify that you have a physical impairment that prevented you from doing the field sobriety tests correctly. It may be that you had bloodshot eyes because you had not slept, have bad allergies, or wear contact lenses. You may have performed poorly on the field sobriety tests because the instructions were not properly given – or because the tests were given in poor weather conditions.
Breath and Blood Test Defenses
In Colorado, the blood or breath test must produce a BAC result of 0.08 or higher in order for you to be convicted of DUI (unless the case is based on drug consumption). Police officers will ask you to provide a blood or breath sample in nearly every drunk driving case. The results are obviously a critical part of the prosecutor's case against you. If there is a way to effectively challenge the test results, it may result in the evidence being thrown out in your case. Colorado law establishes requirements as to how the blood and breath tests must be given to a driver. There are rules about how the machines must be maintained, serviced, and calibrated. If these procedures were not followed, or if there is evidence that the machine was not working properly, the test result may be thrown out. Likewise, if there is information that the technician giving the test was not competent, did something wrong, or was not properly certified, the BAC test result may be suppressed by the judge in your case. Even in cases where the judge does not suppress the evidence, and it is used by the prosecutor at trial, your lawyer may be able to show the jury that it is not a reliable test result.