If you got arrested for DUI in Coastal Georgia and your blood alcohol concentration came back close to the legal limit, you might have more options than you think. One defense that comes up often in these cases is called the rising blood alcohol defense. It’s based on simple biology: your body doesn’t process alcohol the instant you drink it. There’s a delay, and that delay can matter a lot when it comes to your case.
This post breaks down what the rising blood alcohol defense means, how it works in Georgia, and what factors can affect whether it applies to your situation.
How Blood Alcohol Concentration Changes Over Time
Blood alcohol concentration, or BAC, is not a fixed number. It moves. After you take a drink, the alcohol travels from your stomach into your small intestine and then into your bloodstream. This takes time. Depending on the person and what they drank, it can take anywhere from a few minutes to a couple of hours for BAC to reach its highest point.
Once your body has absorbed as much alcohol as it’s going to from that drink, your BAC starts to fall. Your liver breaks the alcohol down and your body clears it out. So at any given moment after drinking, your BAC is doing one of two things: rising or falling. It’s rarely sitting still.
This matters in a DUI case because Georgia, like other states, uses a per se law. Under Georgia Code § 40-6-391, it’s illegal to drive with a BAC of 0.08% or higher (lower limits apply for drivers under 21 and commercial drivers). The law focuses on your BAC while you were behind the wheel, not your BAC at some later point when police tested you.
What the Rising Blood Alcohol Defense Argues
The rising blood alcohol defense says that a driver’s BAC was actually under the legal limit while they were driving, but it kept climbing and crossed 0.08% by the time officers ran a breath, blood, or urine test.
Here’s why that gap can happen. A person gets pulled over. Officers might run field sobriety tests first. Then comes the arrest, the drive to the station, paperwork, and finally the chemical test. All of that takes time, sometimes an hour or more. If someone had their last drink shortly before driving, their body may still have been absorbing that alcohol the whole time. The number on the test could be higher than what it actually was on the road.
Prosecutors know this too, and they can use the same science against a defendant. If a driver’s tested BAC came back close to the limit, a prosecutor might argue the opposite: that the driver’s BAC was actually higher while driving and had already started dropping by the time of the test. This is sometimes called the falling BAC argument, and it shows this science can cut both ways depending on the timing and the numbers involved.
Factors That Affect How Fast BAC Rises
No two people process alcohol at the same speed. A number of things play into how fast someone’s BAC goes up after drinking, including:
- Body size and weight
- Whether there was food in the stomach
- How much alcohol was consumed and how strong the drinks were
- How fast the drinks were consumed
- Gender, since men and women often metabolize alcohol at different rates
- Overall health and liver function
Because of all these variables, two people who drink the same amount at the same time can end up with very different BAC readings an hour later. This is part of why an expert is usually needed to walk a jury through what happened in a specific case rather than relying on a one-size-fits-all formula.
How This Defense Gets Used in Court
To make the rising blood alcohol defense work, a defense lawyer typically needs expert testimony. A toxicologist or similar expert looks at the facts of the case, including when the person had their last drink, when they were stopped, and when the test happened. From there, the expert works backward to estimate what the driver’s BAC likely was at the actual time of driving. This process is often called retrograde extrapolation.
This defense tends to work best when the tested BAC is close to the 0.08% line, not way above it. If someone blew a 0.16%, arguing that their BAC was rising probably won’t get them under the limit at the time of driving. The defense also depends heavily on timing. A bigger gap between the stop and the test gives more room for this argument to hold up.
Frequently Asked Questions
Does Georgia Limit How Long After Driving a BAC Test Can Be Given?
Georgia law focuses on BAC at the time of driving, and chemical testing is expected to happen within a reasonable time after arrest. Longer delays between the stop and the test can actually support a rising blood alcohol argument, since more time gives a driver’s BAC more room to have changed before testing occurred.
Can the Rising Blood Alcohol Defense Work If My BAC Was Well Above the Limit?
It’s much harder to use successfully in that situation. This defense works best when a tested BAC sits close to 0.08%, since that’s where a small shift in timing could realistically move the number below the limit. If a test result is far above the limit, the math usually doesn’t work in the driver’s favor.
Do I Need an Expert Witness to Use This Defense?
In most cases, yes. Juries aren’t expected to already understand how alcohol absorption and elimination work, so an expert, often a toxicologist, explains the science and offers an opinion on what the driver’s BAC likely was while driving. Without that testimony, this defense is difficult to establish.
Talk to a Savannah DUI Lawyer About Your Case
A DUI charge doesn’t have to be the end of the story, especially if your BAC results were close to the legal limit. Jarrett Maillet J.D., PC, can look at the details of your arrest, including the timeline between the stop and the test, and let you know if a rising blood alcohol defense could apply to your case. Call 912-713-3426 for a free consultation to talk about your options and what steps to take next.
