The “Rising BAC” Defense

Facing DUI charges can be extremely stressful. Like other major events in life, there are likely people around us who have gone through the process or know someone else who has gone through it and draw upon those experiences to provide us with advice. Advice often includes the type of defense strategies that worked for other individuals. One such defense strategy is the “rising BAC” defense. While there is a place for this type of defense strategy in a DUI case, it is important to remember that every single case is unique and different, and what works in some may not be useful in others. Understanding the nuances of different defense techniques can help you understand why an experienced criminal defense attorney considers using certain strategies and not others, such as the “rising BAC” defense.

Understanding “Rising BAC”

BAC refers to your blood alcohol concentration, or the amount of alcohol present in your bloodstream. Alcohol takes time to be absorbed into your body. This is why you do not always stop getting more intoxicated simply by virtue of not drinking more. Basically, a “rising BAC” is a term used to refer to the alcohol absorption process which could indicate that an individual was not drunk when he or she was arrested under suspicion of DUI, but only attained the level of intoxication required for a DUI after their BAC continued to rise naturally as more alcohol was absorbed.

Common Circumstances

A “rising BAC” defense can most appropriately be applied to the following types of DUI circumstances:


  • Delays Before Chemical Testing: If law enforcement officials delay the chemical testing process by having you perform roadside sobriety tests, gathering background information about you, arresting you, then having you wait additional time between the arrest and chemical testing, there could be an argument that this delay allowed your BAC to continue to rise to an illegal level;
  • Testing Close to Legal Limit: If your BAC tests close to the legal limit of a DUI, which in Colorado is 0.08%, then it is possible that a defense strategy including the “rising BAC” argument could be employed; and/or
  • Lack of Aggravating Circumstances: If you did not exhibit clear signs of intoxication at the time you were pulled over and arrested, such as slurred speech and/or swerving while driving, then it can sometimes be more difficult for prosecutors to prove their case and there may be room for a “rising BAC” defense.


It is also important to remember that Colorado law also allows Colorado law enforcement officers to issue citations for Driving While Ability Impaired (“DWAI”) if your blood alcohol concentration is between 0.05 and 0.08%. While conviction for a DWAI is less severe than for a DUI, it still carries serious criminal penalties.

Legal Assistance with Your Colorado DUI

Whether you are facing your first DUI charges or are considered a repeat offender, it is important that you work with an experienced Colorado criminal defense attorney who understands the nuances of DUI law and the individuality of each client. A “rising BAC” defense may not be right for you, and another strategy could line up more with your needs. Contact the criminal defense team at Tiftickjian Law Firm to schedule a consultation where you can find out more information about the charges you are facing as well as what options might be available to you in your defense.

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(image courtesy of Andrew Peloso)