A Strategic Guide for Clients of Beltz Law Group
Texas DWI Defense Attorney
In many Texas DWI cases, the State’s primary evidence is a single number—your Blood Alcohol Concentration (BAC) at the time of the test. However, there is a fundamental scientific flaw in relying solely on that number: Your BAC at the station is not necessarily your BAC while you were driving.
Under Texas law, the State must prove you were intoxicated at the moment you were operating a vehicle. At Beltz Law Group, we use the “Rising BAC” defense to show that while you may have been over the limit during the test, you were legally sober behind the wheel.
The Science of the Alcohol Curve
Alcohol is not absorbed into your bloodstream instantly. It follows a predictable scientific path known as the Alcohol Concentration Curve. This curve consists of three distinct phases:
The Absorption Phase (Rising): After you take a drink, your BAC begins to climb as the alcohol moves from your stomach into your bloodstream. This can take anywhere from 30 minutes to two hours.
The Peak: The point where your BAC reaches its maximum level.
The Elimination Phase (Falling): Your liver begins to process and remove the alcohol, causing your BAC to drop.
How the “Rising BAC” Defense Works
The “Rising BAC” defense is based on the Absorption Phase. Because there is always a delay between your traffic stop and the breath or blood test at the station—often an hour or more—it is scientifically possible that:
- At 11:00 PM (Driving): Your BAC was 0.06% (Under the legal limit).
- At 12:00 AM (Testing): Your BAC has risen to 0.09% (Over the legal limit).
If we can prove that your BAC was still rising during that hour you spent in the back of a patrol car, we can create reasonable doubt as to whether you were actually intoxicated while driving.
Factors That Influence the Rise
DWI Attorney North Texas
Every body processes alcohol differently. To build a successful Rising BAC defense, we look at several critical variables:
- The “Chug-a-lug” Factor: Did you finish your last drink right before getting into the car? This often leads to a sharp rise in BAC after the stop.
- Food in the Stomach: A full meal can slow down the absorption of alcohol, causing your BAC to peak much later than it would on an empty stomach.
- Type of Drink: Carbonated drinks or high-concentration spirits are absorbed at different rates.
Retrograde Extrapolation: The State’s Counter-Attack
Prosecutors often try to combat this defense using Retrograde Extrapolation—a mathematical attempt to “guess” your BAC at the time of driving by working backward from your test result.
However, the Texas Court of Criminal Appeals (in the landmark case Mata v. State) has ruled that this science is only reliable if the expert knows a variety of personal factors, such as your weight, when you last ate, and exactly when you stopped drinking. If the State’s expert doesn’t have these details, their “math” is often little more than guesswork, and we can move to have their testimony excluded.
Why You Need a Science-Based Defense
A DWI trial in North Texas is often a battle of experts. At Beltz Law Group, we don’t just accept the State’s numbers at face value. we work with toxicologists to analyze your specific timeline and body chemistry, aiming to prove that the “snapshot” taken at the police station doesn’t tell the whole story.
Did you finish your last drink shortly before your traffic stop? The timing of your consumption is the key to your defense. Let us help you use the science of the human body to fight for your freedom.
