The use of circumstantial evidence is heavily relied upon the prosecution in order to prove the elements of a crime when direct evidence such as witness observations of the crime or confessions from the defendant are not available. In DUI cases, it is important to remember that the prosecution must not only prove that you were driving the vehicle, but that you were intoxicated at the time you operated it beyond reasonable doubt.

There is a caveat to this requirement. Under Vehicle Code 23152, if a blood test or breathalyzer reveals that the defendant had a 0.08 percent blood alcohol content (BAC) within three hours after driving, there is a rebuttable presumption that the defendant had a 0.08 percent BAC at the time he or she was operating the vehicle. This means that the burden is shifted to the defense to prove that his or her client was not over the legal limit at the time the client is alleged to have been driving the vehicle, or in the alternative, that the defendant did not operate the vehicle while intoxicated. This varies significantly with the typical burden of proof that requires the prosecution, not the defense, to prove each element beyond a reasonable doubt.

To rebut this presumption, many defense attorneys have relied on what is known as the Rising Blood Alcohol defense. When you consume alcohol, it absorbs into your bloodstream causing your BAC to rise at a rate dependent upon several factors, such as the type of food and the time you ate that day, the type of alcohol you drank, and your overall pattern of drinking. Your BAC will continue to rise until it has reached “peak absorption”, meaning that your body is no longer absorbing alcohol into the bloodstream.

The defense goes somewhat like this: if you have submitted a breathalyzer sample or blood test prior to reaching your peak absorption, the results will reflect your BAC at the time the test was administered rather than at the time you were operating a motor vehicle. Thus, if your BAC is “on the rise” at the time the test is administered, your defense attorney can argue that your BAC was actually lower at the time you were operating the motor vehicle.

For example, if john submits to a blood sample two hours after he was pulled over and the results reveal a BAC of 0.12 percent, the defense will argue that at the time of actually operating the vehicle, John had a BAC lower that 0.08, since John’s BAC was rising between the time he was pulled over and the time the test was administered, his actual BAC while operating the vehicle was less than the legal limit set at 0.08 percent. Such a defense usually requires a testimony of a qualified expert witness who will testify to the validity of such scientific data and the theory behind peak absorption rates.

Keep in mind that every DUI case is unique and the outcome dependent upon the facts and circumstances surrounding each individual case. An attorney will help guide you through the process and determine whether or not it is worth your time and money to challenge a DUI in court.

Wallin & Klarich DUI lawyers have over 30 years helping clients facing DUI charges throughout Southern California. If you or a loved one is recently facing charges for driving under the influence, please contact your Wallin & Klarich DUI attorneys at (877) 4-NO-JAIL or (877) 466-5245 for immediate assistance.

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