free consultation
Experienced and Affordable DUI Defense for the Denver Metro Area

Blood Alcohol Content and BAC Test

In Colorado, three methods are used by police to measure a driver’s Blood Alcohol Content, or “BAC.” Only two of those are admissible as evidence in court.

The Preliminary Breath Test:
The small hand-held breath test that the officer makes you blow into while you are still at the scene of your arrest is not admissible at trial. This “Preliminary Breath Test,” or “PBT,” cannot be used either by the District Attorney or your defense lawyer to prove their case. This is because the Colorado courts have decided that that test is not reliable and accurate enough to be used as evidence. You have a right to refuse this test and should politely decline when you are asked to do so.

The Test that Counts:
The officer will ask you if you will submit to a blood or breath test at the police station or hospital. You should be given the option of taking a blood test or a breath test. The breath test will be performed on a large machine that rests on a table-top (as opposed to the hand-held type). The blood test is performed by drawing two vials of blood. It is better to choose the breath test over the blood test.

You also have a right to refuse this test. However, in most cases you are better off agreeing to take the test. First time DUI offenders will lose their license to drive for a full year, without the possibility of getting a probationary license, if they refuse to take this test. In addition, the prosecutor will be allowed to tell the jury who decides your case that you refused to take the test, and imply that you knew that you were guilty.

Please keep in mind, you can remain silent, and not answer any questions, and the District Attorney will not be allowed to tell the jury that you refused to speak. However, your refusal to take the BAC test is an exception to your Constitutional Right against self-incrimination. As a result, if you refuse the test, the District Attorney is going to tell that to the jury, and that is not great evidence for your defense case. Since your refusal will become an issue at trial, it is better to show the jury that you complied with that particular request. Leave it to your DUI attorney to challenge the legality or the accuracy of the breath test.

Your attorney will study all aspects of your blood or breath test to determine if it was performed in line with all legal requirements, including such things as what time it was taken, who took it, how the sample was handled – just to name a few. Additionally, your attorney can examine the statistical history of the machine that tested you, and see data about the machine at the exact time of your test. A machine’s errors can be uncovered by your DUI lawyer, and help you to avoid a conviction based on inaccurate blood alcohol data.