Napa County Courthouse

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 Napa County law enforcement, then the later test results in Napa 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.

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

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

Let's say you live in American Canyon and you arrive at a party in Calistoga 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 29 South from Calistoga back to American Canyon. As time progresses during your driving, your blood alcohol concentration ("BAC") will be rising. For example, when you reach St. Helena, your BAC may be .04%, still below the .08% legal limit. However, by the time you reach Napa, your BAC may be at .09%, 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 CHP in Yountville? 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, let's say that your BAC has risen to .13%. Click here to see Scientific Examples Of Rising Curves.

The defense.

The law allows the Napa County prosecutor a legal presumption, to argue to the jury in a Napa 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 Napa 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 Napa County court and at Napa DMV.

This defense is strongest for a Napa 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 Napa 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 Napa County DUI lawyer may have difficulty convincing a Napa jury or the DMV later that you are telling the truth when you testify differently than the police report account by Napa County law enforcement. This is why Napa 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, Wine Country resident for over 20 years, handles only DUI cases, including thousands of North Bay 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.



Phone Hours: 6am - 6pm Everyday

Fax Only: (707) 540-6056

Dave Jake Schwartz, PC

California State Bar No. 138607

Wilber Law Offices

My Case

Dave Jake Schwartz