In South Carolina, it is illegal to operate a motor vehicle if you have a blood alcohol concentration above 0.08%. If you drive under the influence of alcohol, you face a variety of criminal and other consequences. While officers from law enforcement agencies around the Palmetto State regularly stop individual motorists for suspected drunk driving, they also rely on sobriety checkpoints to catch drunk drivers.

With a routine DUI stop, an officer must have reasonable suspicion the driver is violating some law. The officer does not have to suspect a motorist has had too much to drink, though. On the contrary, violating even ordinary traffic laws is sufficient. Sobriety checkpoints, by contrast, occur when officers stop motorists who pass a certain point. When it comes to DUI roadblocks, however, neutrality is critical.

A predictable pattern 

Officers certainly have the legal ability to stop every driver at a DUI checkpoint. Because doing so would likely cause great inconvenience to both officers and motorists, law enforcement professionals typically stop a sample of passing drivers. Authorities may not be arbitrary when deciding which vehicles to stop, however. Instead, they must use a predictable pattern. For example, officers may choose to direct every fifth vehicle to the side of the road for a short inspection.

Discrimination 

When deciding which vehicles to stop during a sobriety checkpoint, officers must take extra care not to engage in discriminatory behavior. Pulling over vehicles because of the sex, race or national origin of drivers clearly violates both federal and state law. If officers have biased motivation for stopping a motorist, even if it is not clearly discriminatory, they may also run afoul of the driver’s legal protections.

If you want to avoid a DUI arrest at a sobriety checkpoint, you should not drink and drive. Still, if you suspect officers conducted a roadblock in a non-neutral way, you may have a valid defense. Accordingly, it is important to investigate whether officers followed established guidelines when conducting the DUI checkpoint.