Can a Breathalyzer Test Have a False Positive?

Charlotte DWI Lawyer Brad Smith answers the question: “Is there more than one way for police to charge a person with DWI?”


We all know the dangers of drinking and driving. Accidents happen everyday because a driver is under the influence of drugs or alcohol and injures or kills someone else. Driving while impaired (DWI) charges are taken very seriously in North Carolina. It can be extremely frustrating to be facing these charges when you know you were not operating your vehicle while impaired. Find more resources about DWI here.


Wine-and-glasses-Charlotte-Monroe-Mooresville-DWI-Lawyer-239x300One of the ways that police detect impaired drivers is through a breathalyzer test to test a blood alcohol concentration (BAC). This is a device that the suspected impaired person will blow into and the concentration of alcohol in the driver’s system. It is illegal to operate a vehicle with a BAC of over .08%. The breathalyzer test can lead to the arrest and subsequent criminal charge of a DWI. However, breathalyzers are not always accurate. They can malfunction just like anything else. The following are reasons that a breathalyzer’s reading might be inaccurate or the reading could indicate a high BAC when you know you have not been drinking.


Consumption of Something Other Than Alcohol


A breathalyzer test measures the presence of alcohol on your breath. Alcoholic beverages are not the only things that contain alcohol. Certain mouthwashes, cough syrup, or even some breath mints could give off the impression that there is more alcohol in your system than there actually is.


Improper Training


Police officers that are administering the breathalyzer test must do so in the proper manner, according to police procedures. Officers are supposed to watch and observe the suspect for at least 15 minutes before administering the breathalyzer test. This is to make sure that the suspect does not consume anything else or do anything before providing the breath sample. If an officer skips the necessary steps before administering the breathalyzer test, the accuracy of the results can be questioned. Police officers must undergo formal training to ensure they know how to administer the test, look out for certain factors that could skew results, and overall be knowledgeable in the administration.


Equipment Malfunction


The breathalyzer machine can malfunction. Breathalyzers must be federally approved and calibrated after every use. If the device was improperly calibrated or records not kept on the maintenance of the machine, inaccurate results could happen.


Health Conditions


An individual’s health conditions can also affect the breathalyzer test results. Medical conditions, like diabetes, that produce a high number of ketones in the body, can be improperly identified as alcohol. If you have not consumed alcohol, but have a reading on a breathalyzer test, it could be a medical condition.


The criminal defense attorneys at Arnold & Smith, PLLC are here to help you following a DWI charge. Proper administration of the test via police protocol and taking into account an individual’s actions are necessary to ensure that the charges are only filed in the proper circumstances. We work to provide the best defense possible, including disputing the results of a breathalyzer test. Contact us today for a consultation. If you find yourself facing criminal charges and need the help of an experienced criminal defense attorney in or around Charlotte, Lake Norman, or our new office in Monroe, please contact Arnold & Smith, PLLC today at (704) 370-2828 or find additional resources here.








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.





Image Credit:



See Our Related Video from our YouTube channel:



See Our Related Blog Posts:

Delayed Release from Jail Causes Charlotte, NC Judge to Dismiss Drunk Driving Charges

You Need an Attorney to Help Fight a DUI

Contact Information