North Carolina’s Court of Appeals recalled State v. Townsend, a decision handed down earlier in the week which seemed to suggest that all a police officer needed in order to arrest someone on suspicion of a DWI was an odor of alcohol and a positive PBT. The decision, which when against prevailing law more fully articulated by Shea Denning at the School of Government, that odor alone is not sufficient to support an arrest.

Does a “positive” result combined with an odor of alcohol, like the 0.13 result in Rogers, give rise to probable cause? Even without a specific alcohol concentration, a positive alcohol screening test result adds evidence that the defendant has consumed alcohol by ruling out other explanations for the odor (for example, that a beer spilled on the defendant). What it does not do is add evidence that the per se alcohol concentration is met or otherwise evidence impairment. In essence, the alcohol screening test bolsters the smell.