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Top Ten Tips > Fighting a DUI Arrest

3. Rising Blood Alcohol

If your body is still absorbing alcohol at the time that the blood alcohol testing is administered to you by Sonoma County law enforcement, then the later test results in Santa Rosa will not be an accurate reflection of your alcohol level at the time of driving. This defense usually arises when you drank alcohol just prior to driving.

DUI Lawyer Defense Example: Rising BAC GraphA Rising Blood Alcohol example.

Your Sonoma County DUI attorney should explain a rising blood alcohol case to you this way:

Let's say you live in Cloverdale and you arrive at a party in Petaluma at 10:00 p.m. You have had nothing to drink and you have no alcohol in your body. Minutes after arriving you drink three healthy shots of tequila on a dare. Right then you see your ex at the party and decide to go home. At 10:05 p.m. you leave and drive Highway 101 North from Petaluma to Cloverdale. As time progresses during your driving, your blood alcohol concentration ("BAC") will be rising. For example, when you reach Santa Rosa, your BAC may be .04%, still below the .08% legal limit. However, by the time you reach Healdsburg, your BAC may be at .11%, and by the time you reach home, your BAC may have reached close to twice the legal limit at .15%.

But what if you are stopped by Sonoma County CHP in Windsor? Let's say that your BAC at the time of that stop is .06%. But your alcohol absorption doesn't stop just because your vehicle stopped. By the time you take a breath test, typically 15-25 minutes after the police stopped you, your BAC may have risen to risen to .13%, approaching twice the legal limit. Click here to see Scientific Examples Of Rising Curves.

The defense.

The law allows the Sonoma County prosecutor a legal presumption, to argue to the jury in a Santa Rosa courtroom that the .13% result in the above example is presumed to be your BAC at the time of your driving (because obviously the police can never test you at the time you are actually driving). This presumption is discussed in further detail in Tip #7 of this section. But if your Santa Rosa DUI attorney can show by affirmative evidence that it is more likely your BAC was below .08% at the time you were observed driving (which is the only legally relevant time -- it is not illegal to be over .08 while stopped at the side of the road) then you may win your case in Sonoma County court and at Santa Rosa DMV.

This defense is strongest for a Sonoma DUI lawyer when your test results show lower blood alcohol levels and if you offered a credible drinking history, supporting an upward absorption graph, at the time you were interviewed by the Sonoma County police prior to arrest. If you took a preliminary breath test prior to arrest that actually shows you were below .08% with later tests showing modest gains, then you may have a very strong defense.

On the other hand, if you lied when interviewed at the scene (most people do), and said you had nothing to drink all night, or "just one drink hours ago," then your Sonoma County DUI lawyer may have difficulty convincing a Santa Rosa jury or the DMV later that you are telling the truth when you testify differently than the police report account by Sonoma County law enforcement. This is why Sonoma DUI lawyers nearly always suggest that during an encounter with law enforcement, it is best to say nothing at all about your activities, but never lie.

Click here to see an example of a winning DMV Case Applying the Rising BAC Defense.


Any result portrayed was dependent on the facts of that case, and the results will differ if based on different facts.

Our DUI Lawyers

Dave Jake Schwartz is an Honors Graduate from UC Hastings Law School, and UC Davis, former Federal Judicial Clerk, and Nationally Qualified Sobriety Tests Practitioner. Member of the California Bar for 30 years, Sonoma County resident for over 20 years, handles only DUI cases, including thousands of Sonoma County DUIs and DMV hearings: first/multiple offenders, minors, seniors, tourists, undocumented immigrants, veterans, probation violations, suspended license, public intoxication, open container, minor in possession, child endangerment, collisions, hit and run, evading, resisting arrest.


Dave Jake Schwartz