In the event that the police accuse you of driving while under the influence in Arizona, it is highly likely that one of the key pieces of evidence against you is a breathalyzer reading. A breathalyzer is a specific type of machine that requires a suspect to breathe into it to produce a reading. This reading is what the police use to determine your blood alcohol level (BAC).
These machines are generally accurate, but they are still machines. Not only does the police officer operating the machine need appropriate training on how to use it, but the device must undergo regular calibration. According to FindLaw, it is possible for a DUI defendant to challenge breathalyzer evidence by demanding that the police prove that the officer using the device properly calibrated it for use.
How often should officers calibrate a breathalyzer machine?
This depends on the laws in your particular jurisdiction, but there are many commonalities between jurisdictions and states. For instance, the breathalyzer device itself must appear on a list of acceptable devices. The officer administering the breathalyzer test must ensure that the subject has not vomited, smoked, burped or regurgitated for a preset of time prior to testing.
Finally, in most cases the courts will wish to see at least two readings that produce a BAC within a measure of .02 of each other.
How can I show that the breathalyzer was not calibrated properly?
Depending on your case, it is possible for the defendant to show that the police were not calibrating the device properly or that the device produced erroneous readings. Usually, this involves the defense attorney sending a subpoena for the calibration records of the breathalyzer device.