Many people in Rocky Mount, North Carolina, may not know it, but they can be on the receiving end of a driving while impaired charge even if they have not had a drop to drink. The reason is that, in North Carolina, a person can be charged with DWI for what the law calls an impairing substance.

An impairing substance includes any illegal drug, as well as any other medicine, lawfully prescribed, that can affect a person’s mental or physical ability to drive. A combination of drugs and alcohol can also be an impairing substance.

Unlike alcohol, there is no well-established process that police use to measure how much drugs are in a person’s system and, thus, whether a person is impaired. Therefore, police frequently rely on what are called Drug Recognition Experts to give a professional opinion as to whether a motorist is under the influence of a drug.

DREs, however, are not doctors or medical professionals but police officers who are trained to recognize people who are under the influence of drugs, even if their blood alcohol content is low. They go through training that has been endorsed by a federal agency and other groups, and they must follow a defined process when examining a motorist.

However, the opinion of a DRE should not be taken as the gospel truth. A North Carolina resident who is facing a DWI may have some valid defenses to a charge that they drove under the influence of drugs, and an independent investigation may call in to question the DRE’s opinion.