What is a 'Rising Blood Alcohol' Defense in a DUI Case?

There are a number of DUI defenses that may be argued when representing an individual charged with a DUI offense. The prosecution must be able to prove that the defendant’s BAC was 0.08 percent or above at the time that he or she was driving a vehicle. However, if the defendant was experiencing a “rising blood alcohol,” the defense may be able to show that the driver’s BAC at the time of driving was actually under the legal limit.

When a person drinks alcohol, his or her blood alcohol content will slowly rise as the alcohol enters the person’s system, plateau, and then fall back down to zero as the body eliminates the alcohol. The BAC rise does happen instantaneously and person’s BAC will slowly rise after alcohol has been consumed.

In order to prove a DUI case, the prosecution will present the results of breath or blood tests that show the defendant’s BAC. However, these tests only show the driver’s BAC at the time the test occurred. Sometimes, the test is not conducted until hours later. If a driver was experiencing a rising blood alcohol, the results of the test may show a BAC of 0.08 percent or higher while the true BAC at the time of driving may have been below 0.08 percent. If the defense can establish that the defendant’s BAC was below the legal limit at the time of driving, there may be grounds to have the DUI charges rejected or dismissed.

In pursuing a rising blood alcohol defense, it may be necessary to use the services of a toxicology expert who can perform an analysis based on the available evidence to determine the driver’s actual BAC at the time of driving. The expert will look at evidence such as the timing of alcohol consumption and the amount of alcohol consumed, the defendant’s age, sex and weight, the results of the preliminary alcohol sensor (“PAS”) test, if available, and the results of the breath or blood test. Based on this evidence, the toxicologist may be able to perform a retrograde extrapolation analysis to show that the defendant had a rising BAC and was actually under the legal limit at the time of driving.

In many cases the results of the PAS test taken during the DUI investigation will be lower than the results of the breath or blood test taken later after the driver has been arrested. This would be clear evidence that the defendant was experiencing a rising blood alcohol level.

The prosecution may present their own expert witness to show that the defendant’s BAC was actually above the legal limit at the time of driving. The defense would be able to cross-examine the expert and present its own expert to testify about the defendant’s BAC at the time of driving.

Where there is a strong rising blood alcohol defense, the prosecution may consider offering a reduced DUI charge, such as wet reckless pursuant to California Vehicle Code Section 23103/23103.5 VC, “dry reckless” under California Vehicle Code Section 23103 VC or exhibition of speed in violation of California Vehicle Code Section 23109(c) VC.

If you have been charged with a DUI offense and want more information about the rising blood alcohol defense, it is critical that speak with a knowledgeable DUI attorney as soon as possible. As a former Deputy District Attorney with over 14 years of prosecutorial experience, Michael Kraut understands how to effectively fight DUI charges. Mr. Kraut works with the top toxicology experts in the area in order to ensure every avenue of defense is fully explored.

For more information about DUI and the rising blood alcohol defense, and to schedule your free consultation, contact Michael Kraut at the Kraut Criminal & DUI Lawyers located at 6255 Sunset Boulevard, Suite 1520, Los Angeles, CA 90028. Mr. Kraut can be reached 24/7 at 888-334-6344 or 323-464-6453.