Colorado Laws On DUI Breath And Blood Tests

When law enforcement officials have reasonable cause to suspect drivers of DUI, they can request that the accused take a breathalyzer test or submit to a blood test in order to assess the blood alcohol content (BAC) of the accused (a measured BAC of .08 will result in DUI charges, according to Colorado law).

In these circumstances, whether or not to choose a breath test versus a blood test — or whether to refuse testing altogether — may not be clear to the accused, and making the right choices in these delicate situations will be a critical part of their defense (or the prosecutor’s arguments). At Flesch & Beck Law we advise our clients regarding the best possible choices in these circumstances (as the best choice can vary from case to case), and also:

  • Review the facts of the case to assess whether these tests were properly administered (and whether there was even reasonable cause to pull the accused over in the first place)
  • Challenge the results of either test if questionable circumstance are involved
  • Build the strongest possible defense cases for our clients in an effort to resolve these matters as beneficially as possible

Breathalyzer Versus Blood Tests, Consequences Of Refusing Testing

When choosing between a breath and blood test upon being pulled over for a DUI, in general, it is better for individuals to choose the breathalyzer, as these tests are typically less accurate than blood tests, and they often produce different results upon retesting. Additionally, roadside breath tests with hand-held breathalyzers are not admissible in court, as they are considered to be preliminary breath tests; only the results from table-top breathalyzer machines at police stations will be allowed for presentation in court. Should you refuse to take either the breath or blood test:

  • The DMV will likely suspend your driver’s license for up to one year (or possibly longer if you have multiple DUIs).
  • The prosecutor can use your refusal as an argument toward trying to prove guilt, implying that you had something to hide — like being under the influence of alcohol or drugs.

Regardless of the choices you make after being pulled over for a DUI, it’s vital that you retain our trusted Denver DUI attorneys in order to achieve the best possible outcome to your case. For a FREE, no-obligations evaluation of your case, contact us today by emailing us or calling 720-689-0322.

YOU Deserve 1-on-1 Representation

Please call us at 720-689-0322 or email our team to speak with an attorney. We look forward to speaking with you.


Settlement for a family who lost their oldest son in a horrible accident.

$14 Million

Verdict on behalf of a group of clients who were defrauded by a financial investment agent.

$3 Million

Kevin Flesch was lead class counsel for an action against the United States Postal Service.

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