Breathalyzer tests may be used by police officers to help determine whether probable cause exists to make a DUI arrest. Breath tests measure the blood alcohol level in a driver's system. The intoxication limit in all 50 states is 0.08 percent.
What some Prince Georges County residents may not know is that Maryland law forbids results of alcohol breath tests to be used to prosecute someone charged with driving under the influence of alcohol. The prosecution must support its case by producing other evidence of drunk driving, like a blood test, to obtain a conviction.
The results of a breath test remain important to a criminal defendant's case. Even though the results aren't admissible in court for prosecutors, they can be used by a criminal defense attorney to help clear a client's name. Test results must be accurate for the evidence to be effective for a defendant.
Breathalyzers can measure blood alcohol levels accurately when the devices are maintained properly and BAC tests are administered correctly. A breath testing device must be calibrated and tested regularly to ensure reliable results. The officer who asks a driver to take a breath test must be certified to operate the device and conduct the test without errors.
An inaccurate Breathalyzer reading can influence whether a Maryland driver is arrested - a serious legal situation for anyone. A legal defense also could suffer when a dismissal or reduction of charges is dependent upon a breath test's accuracy. The maintenance records of a breath testing device can show whether a Breathalyzer was in good working order at the time a BAC test was administered.
Defense attorneys can argue a faulty breath test led to a wrongful arrest and DUI charge. Defendants' lawyers are also prepared to challenge other evidence like poor operation of a motor vehicle, physical signs of intoxication and failure of field sobriety or blood tests.
Source: FindLaw, "Breathalyzer Calibration," accessed May. 14, 2015