Menu Close Menu

BAC Over The Legal Limit

If the machine registered my BAC over the legal limit, is there any point trying to fight the DUI case?

Yes. Absolutely. Experienced California DUI attorneys help prevent DUI convictions all the time--even in cases where the BAC breath machine says the blood alcohol content is over the legal limit of .08. There are several reasons.

First, the DUI breath machines (such as the Long Beach Police Department's Intoxilyzer 5000, Los Angeles County's BAC Datamaster, Los Angeles Police Department's Intox EC/IR, and San Bernardino County's Draeger Alcotest 7110) are all prone to error. Sometimes the DUI breath machines suffer from technical problems, are improperly maintained, haven't been calibrated, or are not administered correctly by the DUI officer. Even if there are no obvious problems such as these, the breath alcohol machines also suffer from an inherent range of error.

Second, there are often biological factors and medical conditions that cause people to generate falsely high readings on the DUI breath machines. These include, among other things, GERD, acid reflux, heartburn, stomach ailments, fever, illness, braces, cavities, gingivitis, and Adkins-style low-carb diets. Any of these have the potential to cause false and exaggerated BAC results in the DUI breath machines.

Third, a person's BAC is often higher when he takes the test at the police station than it was earlier when he was actually behind the wheel. This occurs because it can take several hours for the alcohol, once consumed, to absorb fully into the DUI suspect's bloodstream. For example, a DUI suspect's BAC may be a .06 at the time he gets pulled over, then rise to a .11 an hour later when the breath test is administered.

This presents a serious challenge for DUI prosecutors. California DUI laws are based on one's BAC level at the time of driving, not at the time of the test. The subsequent DUI breath test results merely provide an inference as to what your BAC may have been at the time of driving. Extrapolating backwards from the time of the breath test to assign a BAC level at the time of driving involves assumptions, speculation and uncertainty. A conclusive inference can rarely be drawn.

And remember: The prosecutor, not citizen accused of DUI, bears the burden of proof in a DUI trial. You don't have to prove that you were below the limit at the time of driving. Rather, the DUI prosecutor must prove that your BAC was at or higher than the legal limit of .08 at the time of driving. And this proof, always, must be demonstrated beyond all reasonable doubt.

The point is this: DUI cases are rarely open and shut. A knowledgeable Los Angeles DUI defense lawyer can win many cases even though the client's BAC level is measured to be at or over the legal limit.

Southern California DUI Defense


DUI cases are rarely hopeless. DUI convictions are almost never inevitable. Clients retain our California DUI defense attorneys for one reason: they want to fight the case. And win.

Contact Us For Help

The police arrested you for DUI. You gave a blood or a breath sample. The DUI officer confiscated you drivers license. The police released you with a notice to appear in court in a few weeks. Where do you go from here? Our lawyers are here to guide you step by step.