Many drivers accused of DUI / DWI in California are charged with violating the state’s “per se” laws in addition to being charged with driving under the influence. Per se is just another way of saying that someone arrested for drunk driving is accused of having a blood-alcohol level higher than allowed – in California, the limit is .08 percent. It’s separate from the accusation that a driver was mentally or physically impaired behind the wheel, or driving under the influence.
Many people accused of DUI fear that a breath test or blood or chemical test reading of .08 percent or higher means that their case is doomed. But an experienced California DUI / DWI attorney, especially one who has advanced training in field sobriety testing, can effectively challenge the results of both tests, and help accused drunk drivers to win their cases.
In many cases, the blood alcohol content (BAC) of a suspected drunk driver is tested hours after the driver was last behind the wheel of a car. It’s not against the law to have a BAC of .08 or .14 at the police station, where the test is given, but many prosecutors try to use that information to convict suspected drunk drivers of violating California’s per se laws.
An attorney skilled at defending DUI / DWI cases knows that a driver whose BAC is above the legal limit at the police station may well have been below the legal limit while behind the wheel. This is because the complex process of absorption and elimination of alcohol in the human body often causes a person’s BAC to rise long after he or she takes that last drink.
Prosecutors get information about a suspected DUI driver’s blood alcohol content from two sources – breath tests and blood tests. Both have big potential for error. Breath tests are conducted both at roadside and at the police station. Roadside breath testers are the worst – the handheld machines have no way of detecting mouth-alcohol, which can substantially increase the reading on a breath test. Mouth-alcohol is especially present in people who may have just left a bar or restaurant where they’ve been drinking.
Police station breath testers aren’t much better. They don’t take the temperature of a person’s breath, even though higher breath temperature can greatly inflate the BAC reading. The biggest problem with both types of breath tester – the portable machines and the ones found in the police station – is that they are calibrated to test an “average” person. Anyone who looks around can see that there is no such thing as an average person – people come in all shapes and sizes, with all different rates of metabolism.
Blood test results can be just as flawed. The integrity of a blood sample can be compromised in a number of ways. Although blood should always be drawn into a tube with white powder in the bottom – the powder is a preservative and anti-coagulant – the powder-filled tubes come from a factory somewhere, and are never checked. Also, in real life, forensic labs don’t work the way they do on TV. Often there’s a delay of days or weeks before the blood gets tested, and mix-ups are more common than most people believe. There have been documented cases of blood samples with different blood types than the individuals from whom they were supposedly drawn.
Although prosecutors don’t want the public to know this, there are several effective ways to challenge evidence in a pro se DUI /DWI case. The best way to fight a per se drunk driving case is to consult with an experienced lawyer skilled in DUI / DWI and drunk driving defense.