All of our readers have heard the term “legal limit” in connection with drunk-driving charges, and know that it refers to a blood alcohol concentration of 0.08 percent. Many states besides Colorado have the same legal limit for drunk-driving, so this is fairly common knowledge.

Many people, through no fault of their own, mistakenly assume that “legal limit” refers to the maximum blood alcohol concentration a driver is allowed to have before they may be charged with drunk-driving.  The assumption here is that one can only be charged with drunk-driving if one has a blood alcohol concentration at or above the legal limit. Unfortunately, it isn’t that simple.

In reality, a motorist can be charged with DUI in Colorado not only if there is reliable evidence that he or she had a blood alcohol concentration of 0.08 or above, but whenever it is determined that he or she was “driving under the influence,” or even for “driving while ability impaired.”

To successfully pursue a DUI case, prosecutors don’t necessarily need evidence that a suspect’s BAC was at or above 0.08, but having that evidence does help. That’s because a BAC at that level gives rise to the inference that the defendant was under the influence of alcohol. That being said, even a lesser BAC–specifically, a BAC over 0.05 percent and less than 0.08 percent–can give rise to a presumption that the driver was impaired by alcohol.

In our next post, we’ll continue this discussion and look at other types of evidence prosecutors may use to pursue DUI charges in Colorado.

Skip to content