Occasionally, it is readily apparent when someone has driven under the influence of alcohol or drugs. That was the case for one North Carolina woman recently who plowed her vehicle into a crowd of concertgoers. One man sustained injuries while police arrested the woman for DUI, leaving the scene of a crash involving injuries, DUI with damage to a person or property and refusal to submit to DUI testing.

In other instances, the police will pull over a vehicle when they suspect the driver is under the influence. The cops may need to administer a breath test to determine if the person has alcohol in his or her system. The problem with this is that those tests are not always accurate. In fact, there can be several reasons for why a breath test device would provide a false positive report, and a driver could build a defense around that.

The officer did not calibrate the device

All police officers must use federally approved breath test devices on drivers. They must also recalibrate the device according to the manufacturer schedule. Additionally, law enforcement must maintain accurate records showing they did, in fact, calibrate the device when necessary. These records can come up in a court of law to show negligence on the side of the authorities.

The driver consumed something besides alcohol

A false positive can be the result of the driver consuming something that contains alcohol. This includes breath mints, cough syrup and mouthwash. Any of these could show there is some alcohol in the bloodstream even though it is not enough to affect a driver’s abilities to operate the vehicle.

The driver has a medical condition

Some health conditions can impact the accuracy of breath test results. For instance, diabetics have increased levels of ketones in their bloodstream, which breath test devices mistakenly read as ethyl alcohol. Similar results can happen to people with GERD or acid reflux due to increased acidity in their mouths.