Defenses to a Failed Breathalyzer Test in North Carolina

Charlotte DWI Lawyer Brad Smith answers the question: “Are breath test results always accurate?”


If you were pulled over for driving while impaired (DWI) in Charlotte or other parts of North Carolina, a police officer might order a breathalyzer test to determine your blood alcohol concentration (BAC).

If you failed the breath test, and this led to your DWI arrest, you may be able to challenge the results of your test with the help of a Charlotte DWI criminal defense attorney.


cocktail-Charlottte-Monroe-Lake-Norman-DWI-Attorney-221x300What is a Breathalyzer Test?

A breathalyzer test is one of DWI field sobriety tests administered by police officers when a driver is suspected of impaired or drunk driving. A breathalyzer test can take two forms:

  • A portable test at the scene; or
  • At the police station after the DWI stop.

A breathalyzer is a device that is intended to assess the BAC in a driver’s body by measuring the amount of alcohol in the breath. If you failed the breath test (the result showed that your BAC is over the legal limit in North Carolina), you are likely to be arrested for impaired driving.

The results of your breathalyzer test will play a major role in your DWI case and sentencing. Although the results of breath tests are relied upon in court, the breathalyzer device is not 100% reliable, not to mention that there is no guarantee that the test was administered correctly to produce accurate results.

Either way, you may be able to challenge your breathalyzer test results.


Can You Refuse a DWI Breath Test in North Carolina?

While North Carolina law does allow drivers to refuse a breathalyzer or any other chemical test, doing so may result in the loss of your license for 12 months.

North Carolina follows the doctrine of “implied consent,” which means that every driver in the state gives automatic consent to chemical testing when charged with a DWI or DUI. However, the revocation of your license can be appealed under certain circumstances.


Defenses to a Failed Breathalyzer Test

A Charlotte criminal defense attorney will review the facts of your failed breath test case to determine how the breathalyzer test was administered and analyzed. When choosing the most appropriate defense to a failed breath test in North Carolina, your lawyer will look for the following errors:

  • The breathalyzer device was not approved by the state of North Carolina
  • The test was not administered correctly
  • The testing machine was not maintained or calibrated properly
  • The officer who administered the breath test was not trained or certified to do so
  • The officer failed to inform you of your right to refuse the test
  • You had a medical condition that affected the results
  • You followed a low-carb/high-protein or keto diet when taking a breath test
  • You smoked tobacco or used mouthwash shortly before the test
  • You burped, vomited, ate, or drank before the test was administered
  • You have acid reflux
  • You took certain medications that may render the breath test results inaccurate

If any of these errors or factors were present in your DWI case, the results of your “failed” breathalyzer test could be inadmissible in court. Speak with a results-driven Charlotte criminal defense lawyer to prove that your failed breath test cannot be used in your DWI case for sentencing. Contact Arnold & Smith, PLLC, to choose the most appropriate defense to your failed breath test. Call (704) 370-2828 to evaluate your options or fill out our contact form. Now taking cases throughout North Carolina with offices in Uptown Charlotte, Mooresville and Monroe.







The criminal defense attorneys at Arnold & Smith, PLLC make it their mission to zealously defend their clients on a wide range of criminal matters at both the state and federal levels. These matters may include any charge from traffic offenses; DWI/DUI; drug charges (from simple possession to possession with intent to distribute and trafficking); gun permit denials; weapons offenses; and property crimes (larceny, breaking and entering, robbery, fraud, embezzlement, white collar offenses); to sexually related offenses (indecent exposure; sexual assault, crimes against nature, removal from sex offender registry); and violent crimes (domestic violence; assault; manslaughter; homicide, murder). Other legal issues that Arnold & Smith, PLLC criminal clients may be facing include restraining orders, restraining order and probation violations, expungements; appeals; and immigration issues related to criminal charges. Our criminal defense attorneys are passionate about ensuring that individuals empower themselves by being informed about their constitutional rights, and stand at the ready to fight in the defense of those facing criminal charges.





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