If you are pulled over and suspected of DUI while your body is still absorbing alcohol, your blood alcohol concentration (BAC) will continue rising after your arrest. Any breathalyzer test or blood test given at this time or later will not accurately reflect how drunk you were while driving. This is what we call the “rising alcohol defense.”
How does alcohol absorption work?
When you have a drink, the alcohol is not all absorbed into your body at once. It’s absorbed slowly, and only the amount of alcohol in your blood (your BAC) affects how intoxicated you are—not the alcohol in your stomach. When you drink, your BAC will slowly rise, plateau for a while, and then fall again as your body eliminates the alcohol. This is why you sometimes feel more drunk after you’ve stopped drinking. In some cases, it can take up to 2 hours for alcohol to reach its BAC peak.
This delay affects your DUI case. Under the law, it’s illegal to be intoxicated while driving. But, even if you had some drinks before getting in the car, you may have been legally sober while at the wheel. Only much later, by the time police were able to test you, had your BAC risen to a point where it would be illegal to drive.
When you are arrested for DUI, police often don’t take these factors into account. Likewise, prosecutors look at your breath test results and make assumptions about what happened. If you can prove that their assumptions are false, the “rising BAC” defense could win your case.
What factors affect the rate of alcohol absorption?
The three biggest factors include:
- How much food you’ve eaten
- How long it’s been since you started drinking
Gender matters because men and women absorb alcohol differently. On average, women have less water in their bodies than men do, which means alcohol does not get as diluted in the body. Thus, women’s BAC typically rises faster than men’s.
Food matters because a full stomach slows the absorption of alcohol. Contrary to popular belief, a full stomach does not make you “less drunk” or prevent intoxication. However, it does slow absorption so that it takes longer to become intoxicated, and you then potentially feel intoxicated longer. This is particularly important in defending against a DUI.
Time matters because it’s the key to the BAC defense. If you had a drink and then immediately got in the car, your BAC probably had not risen much yet. If you only drove a short distance, you may never have been legally intoxicated while behind the wheel.
How does “rising BAC” defend me from a DUI charge?
Under California Vehicle Code 23152(b), it is illegal to drive when you have a BAC of .08% or greater. However, authorities cannot measure your BAC while you were driving. They can only measure it at the time of arrest or later. In some cases, two or more hours go by between being pulled over and having a breath test/blood test. That means the results are wildly inaccurate.
Most California DUIs are charged under VC 32152(b), and the prosecution must prove your BAC at the time of driving in order to convict you. If you can disprove their BAC estimate, they do not have the proof they need and you cannot be convicted.
How can I prove that my BAC was rising?
Experienced DUI attorneys will first construct a timeline of what happened: when you were drinking, how much you had, and when you were pulled over and tested. If the timeline suggests that rising BAC was a factor, they will bring in a professional toxicologist to show that your BAC must have been lower than .08% at the time you were actually pulled over.
What kind of evidence can I use to prove my case?
Any evidence that supports your timeline can be useful. The most common evidence includes:
- Receipts from the restaurant or bar (if any) showing what food and drinks you ordered and when
- Eyewitness testimony stating that you acted sober at the time you got in your car
- A police report that does not describe any erratic or seemingly impaired driving behavior prior to the arrest
Your attorney can help you identify the best evidence to use.
Have you been charged with DUI? We can connect you with an experienced Los Angeles DUI lawyer and get you a FREE consultation. Fill out the form to the right or call (310) 862-0199 and get your free consultation today.