Before issuing a DUI, law enforcement in Virginia generally first consider the suspect’s behavior during the traffic stop. Police may look for such signs as smelling like alcohol and performing poorly on a field sobriety test. However, it is possible that a person who is on a low-carb diet might have breath test results that falsely register a blood alcohol content above the legal limit.
A Texas attorney successfully argued this point for his client, who was in ketosis, and got DUI charges dismissed. He says that the portable tests carried by most law enforcement officer, which use fuel cells, read isopropyl and ethanol alcohol the same way. The former may be produced in the breath of people who are in ketosis, which is caused by a low-carb diet. It can also be caused by certain medical conditions, such as diabetes. A 2006 study examined the case of a man who was unable to start a vehicle with an ignition interlock device that used fuel cell technology despite not being drunk. He was also on a low-carb diet.
One alternative for people accused of drunk driving is going back to the station. Usually, there is a device there that uses infrared spectroscopy. Blood tests may also be more accurate.
Penalties for driving under the influence can be serious. An offender may be required to attend a class on alcohol awareness or install an ignition interlock device on their vehicle. However, an attorney may be able to assist the accused in creating a defense. The defendant may have a medical condition that made them appear as though they were drunk, or a test might be administered inaccurately.