Rizio and Nelson California Law Blog

When an individual is tested by a police officer to determine whether they are drunk, it is common for them to use a breathalyzer test. These are devices that the individual blows air into and they measure the amount of alcohol in the blood by using a mathematical formula. The problem, though, is that these devices are not precisely accurate for each individual. There are many factors that can affect the accuracy of these devices:
the calibration and precision of the device, as well as the type of device used

• the sex of the individual
• atmospheric pressure
• temperature
• the individual’s tolerance to alcohol
• if the individual is a smoker
• if the individual has inhaled fumes such as paint, lacquer, or glue
• if the individual is undergoing fasting or is on a weight loss diet
• the health of the individual, particularly if they have any medical conditions such as alcoholism or untreated diabetes

Because of all of these factors, the California Supreme Court ruled that defendants can challenge the results of a breathalyzer test if they feel that the test did not accurately reflect the amount of alcohol in the individual’s blood. It is important to remember that these devices are calibrated to test the “average” person’s blood alcohol levels. But, because each individual’s body processes alcohol in its own way, and because each individual breathalyzer machine converts it differently, it is nearly impossible to prove what an “average” person’s acceptable levels should be. Justice Carol A. Corrigan wrote, “Evidence casting doubt on the accuracy of the breath-to-blood conversion ratio is just as relevant as other evidence rebutting the presumption of intoxication from a breath test result, such as evidence that the defendant had a high tolerance for alcohol or performed well in field sobriety testing.”
Prosecutors will have a more difficult job of presenting evidence to the court to support convictions. Unless the individual had a blood test taken, it will be difficult to convict an individual based on the results of a breathalyzer test alone. Some prosecutors believe that this ruling will confuse jurors. Justice Corrigan also wrote, “Defense evidence is relevant to rebut the presumption that the defendant was intoxicated, but not to remove the presumption altogether.” This means that jurors will have to consider all evidence carefully, otherwise they may assume that the breathalyzer test was inaccurate.
It will be more important than ever to have experienced legal counsel. Let the attorneys at Rizio and Nelson help you with your case.