Skip to Content
Schedule your Case Evaluation

Breathalyzer Calibration: How it can Affect Your DWI Charge


Police typically employ a breath analyzer machine to estimate the blood alcohol content (BAC) of a driver suspected of drunk driving. These machines, or breathalyzers, receive a breath sample and register the driver's BAC level. While these machines lend evidence regarding a person's BAC, they are not flawless devices.

Many DWI cases have turned on the defense's challenging of the breathalyzer evidence used against the accused. These challenges concern questions over whether the machine is in proper working order and accurate. Poorly maintained devices will give inaccurate results which could be thrown out.

For reliable breathalyzer results which can be faithfully admitted in court, the device must be properly maintained by someone qualified to do so. If it can be proved that law enforcement did not properly calibrate the breathalyzer or that the machine consistently gave false readings, the court will in all likelihood declare the results of the breathalyzer test in question be inadmissible and thrown out of court.

A Dallas criminal defense lawyer can ask for the maintenance and calibration records of the breathalyzer which tested you towards showing that the device was not maintained as it should have been. The burden of proof lies with the state to prove you were intoxicated at this point and they will have to rely on circumstantial evidence such as your appearance when stopped and results of any field sobriety tests.

If you have been arrested for DWI, turn to Mathur Law Offices, P.C. for comprehensive and dedicated representation. Our firm can contest your breathalyzer results no matter what they were.