What is a rising BAC (Blood Alcohol Content) defense?

It is unlawful to have an excessive blood-alcohol concentration (BAC) at the time of driving — not at the time of being tested. Since it takes between 45 minutes and 3 hours for alcohol to be absorbed into the system, an individual’s BAC may continue to rise for some time after he is stopped and arrested.

Commonly, it is an hour or more after the stop when the blood, breath or urine test is given to the suspect. Assume that the result is .12%. If the suspect has continued to absorb alcohol since he was stopped, his BAC at the time he was driving may have been only .07%. In other words, the test result shows a blood-alcohol concentration above the legal limit — but his actual BAC at the time of driving was below. The other side of that is if a person is intoxicated while driving and is stopped, and is no longer absorbing alcohol, as time elapses his blood alcohol level would begin to fall. For that reason, and also to help rule out a rising BAC defense, police officers typically try to do testing as soon as possible.

In addition, this defense is why officers always ask exactly how many drinks were consumed, and most importantly, when. The prosecution is usually helped out by legislation that creates a presumption that the BAC level found at the time of testing was the same as when driving, as long as the test is done within a set time limit. This puts the burden of proof on the defendant, which means he has to hire a toxicology expert to prove his BAC at the time of driving.

Related Articles:
The Advantages of Hiring a Drunk Driving Attorney
How to Hire a DUI Attorney

Case Studies: Rising BAC (Blood Alcohol Content) Defense

Case Study 1: The Late-Night Party

John Doe was pulled over by a police officer late at night for suspected drunk driving. The officer conducted a breathalyzer test approximately an hour after the stop, which showed a BAC level of 0.12%. However, John’s attorney argued the rising BAC defense, claiming that his BAC at the time of driving might have been significantly lower.

With the help of a toxicology expert, John’s defense team demonstrated that he continued to absorb alcohol between the time he was stopped and the breathalyzer test. Ultimately, the rising BAC defense led to a reduction in charges, and John faced lesser penalties.

Case Study 2: The Responsible Driver

Jane Smith was involved in a minor car accident and was taken to the hospital for medical evaluation. Police officers arrived at the scene and later conducted a blood test approximately two hours after the accident. The test revealed a BAC level of 0.09%. Jane’s defense attorney raised the rising BAC defense, arguing that at the time of the accident, her BAC might have been below the legal limit.

To support this claim, Jane provided receipts and testimonies from witnesses at the restaurant she had dined in just before the accident. The evidence indicated that she had only consumed a small amount of alcohol and that her BAC had risen after the collision due to continued alcohol absorption. As a result, Jane’s case was dismissed, as the rising BAC defense created reasonable doubt about her level of intoxication at the time of the accident.

Case Study 3: The Timely Testing

Michael Johnson was stopped by the police on suspicion of driving under the influence. The officers administered a breathalyzer test promptly, within 30 minutes of the stop, and recorded a BAC level of 0.10%. Despite his attorney’s efforts to raise the rising BAC defense, it was challenging to establish that his BAC at the time of driving was lower.

The quick and timely testing by the police worked in the prosecution’s favor, as it made it difficult for Michael’s defense to present compelling evidence supporting the defense. The court upheld the results of the breathalyzer test, and Michael was convicted of DUI.