What types of breath test errors can impact a DUI case?
June 25, 2015
Law enforcement officials typically use blood alcohol tests to determine the blood alcohol concentration, or BAC level, of drivers suspected of driving under the influence. If a driver has a BAC above .08 percent, there is a “per se” legal presumption that the driver was intoxicated behind the wheel.
Breathalyzer tests are one of the most common ways to determine a driver’s BAC level in California. A Breathalyzer test requires the DUI suspect to blow into an instrument which registers the BAC level. Breathalyzer results are accepted in courts as evidence of a driver’s BAC level. However, breath test errors do occur fairly regularly.
In many cases, officers fail to properly administer blood alcohol tests, thereby skewing the results. The testing devices also must be in proper working order when the test is administered. If a Breathalyzer machine is poorly maintained or not calibrated properly, the results cannot be the basis of a presumption of intoxication.
California has its own set of laws in place to address calibration of Breathalyzers. Generally, all states require that a Breathalyzer device is on the list of acceptable devices and that it is regularly checked for accuracy. The person administering the test should be certified and trained in the use of the device and must administer the blood alcohol content tests in accordance with the training. For example, Breathalyzer tests require that the suspect does not eat, vomit, burp, regurgitate or smoke for a certain period of time before the administration of the test. The test must also capture two separate readings within .02 of each other.
If a defense attorney can show that the test was calibrated incorrectly or that the test was not administered according to state laws, the court may find the Breathalyzer results to be inadmissible as evidence. Prosecutors will then have to prove their case through other evidence, such as suspect behavior. Careful scrutiny of breath test errors gives DUI defendants a way to protect their legal rights.