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Calibration of Breath Machines

In a report on Fox News today, the Supervisor of the Washington DC Police Department Breathalyzer Unit has called into question the reliability of hundreds if not thousands of breath tests. According to the report, police officers have been arresting people for DUI in DC based on the results of breath machines that were not calibrated. This may open the door to defense motions to set aside the DUI convictions of hundreds of people based on breath machines that were potentially inaccurate.
In California, the regulations require that breath machines be checked for accuracy at least every ten days or following the testing of 150 subjects, whichever comes sooner. Many law enforcement agencies post the results of these accuracy checks on their website. Orange County Crime Lab does this, as does the Long Beach City Prosecutors Office. In any event, it is a routine step for DUI lawyers in California to obtain a copy of the accuracy checks and maintenance history of breath machines used in DUI cases. If a machine has not been checked for accuracy frequently enough, a motion may be made to exclude the results of the test in evidence. However, most judges view a violation of the rules relating to calibration as relevant to the weight to be given to a test result as opposed to the question of admissability.
Most toxicologists would testify that breath alcohol testing is only accurate of performed on a breath machine that has been properly and frequently checked for accuracy.