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Defenses Against Breathalyzer Reading Evidence

Posted on January 19, 2022 in

If you get pulled over in Massachusetts and blow a 0.08 percent or higher on a Breathalyzer test, this does not necessarily mean that you will be convicted of operating under the influence (OUI). Breath test devices are notoriously faulty and inaccurate, making them unreliable as evidence in court. There may be several ways to defend yourself against Breathalyzer reading evidence. A Middlesex County OUI attorney can help choose the right defense strategy for you. 

Illegal Traffic Stop

First, your lawyer may be able to undermine the traffic stop itself by proving that the officer did not have probable cause to pull you over. In Massachusetts, suspicion of drunk driving is not enough to pull a driver over – the driver must have committed another offense, such as running a red light. If the officer that arrested you didn’t have probable cause to stop you, violated your civil rights or didn’t read your Miranda rights, this could lead to the dismissal of the case despite Breathalyzer evidence.

Breathalyzer Test Malfunction

Breathalyzer tests are not infallible. In fact, many of these devices are old, outdated and cheap in quality. This makes them prone to malfunctions and inaccurate readings. If your lawyer can prove that the breath test failed or there is doubt about the accuracy of the test, this can make it inadmissible as evidence during your OUI case. A Breathalyzer test can give an incorrect reading for many reasons, including:

  • Faulty programming. Breathalyzer tests have sensitive hardware and software that must be carefully programmed to generate accurate readings.
  • Wrong or expired chemicals. Breath tests rely on the right chemical ingredients, correct amounts, and chemicals that are not expired or contaminated.
  • Inappropriate device modifications. A police station may reduce the accuracy of a Breathalyzer test with low-quality (unprofessional) repairs.
  • Poor device maintenance. Breath tests must be regularly inspected and maintained to ensure correct operation.
  • Improper device calibration. Breath tests are sensitive machines that must be calibrated regularly to yield accurate results.

Anything off or lacking in the maintenance, upkeep, preparation or programming of a Breathalyzer test can result in inaccurate results. Your lawyer may be able to prove this defense by hiring breath test experts to examine the device or taking other measures to demonstrate that the test results were inaccurate.

Police Officer Error

Even if a Breathalyzer test is in proper working condition and would have given an accurate alcohol content reading, the police officer could make a mistake while administering the test that renders the results useless. If the officer did not follow proper protocols when administering the Breathalyzer, did not have the proper qualifications or experience, or was not properly trained, the officer could make a mistake that leads to wrong test results. A lawyer may be able to use police department employment records, footage recorded during your traffic stop and testimony from experts to prove issues of methodology.

Biological Factors Unrelated to Alcohol

If your lawyer cannot prove that the results of a Breathalyzer test were inaccurate or incorrect, he or she may be able to base your defense on the argument that you blew a 0.08 percent or higher because of unrelated biological factors, pre-existing conditions or chemical exposure during testing. Many common biological factors can impact blood alcohol testing – especially tests performed using the driver’s breath. These factors include diet, naturally occurring mouth alcohol, acid reflux, diabetes and breathing problems.

If a pre-existing condition that you had at the time of your traffic stop reasonably could have changed the breath test results, this could be enough to get this evidence thrown out. Your lawyer may also be able to demonstrate that the Breathalyzer was exposed to chemicals during your traffic stop – such as substances that you come into contact with at your job – that may have altered the results. Common examples include gasoline, paints, paint stripper, varnish, cleaning products and mouthwash. Contact a criminal defense lawyer as soon as possible after an arrest for more information about potential defenses.