You Can't Tell Just from the Smell

I've been asked more than once about whether the odor of alcohol combined with a positive reading on a portable breath alcohol screening test device, such as an ALCO-SENSOR, without more, constitutes probable cause to believe that a defendant has committed the offense of impaired driving. My answer?  No.  My reasoning? First, you can't tell just from the smell. The state supreme court held in Atkins v. Moye, 277 NC 179 (1970), a civil action arising from a car crash, that "[a]n odor of alcohol on the breath of the driver of an automobile is evidence that he has been drinking [but] an odor, standing alone, is no evidence that he is under the influence of an intoxicant." The court went on to explain that evidence that a driver has been drinking (which one could tell from the smell) combined with bad driving or other conduct indicating impairment is sufficient evidence to show a prima facie violation of G.S. 20-138. Yet probable cause is a lower standard than the prima facie standard applied Atkins and requires only a fair probability that the defendant committed a crime. The court in State v. Dark, 22 N.C. App. 566 (1974), held that an officer had probable cause to arrest the defendant for impaired driving after seeing him drive, lawfully stopping him, smelling alcohol and "observ[ing] his condition." The facts recited in the opinion indicate that the officer immediately arrested the defendant upon smelling alcohol on his breath and that he made no other observations [...]