Portable breath tests don’t go very far anymore in proving whether a suspect is impaired from alcohol. That’s because the legislature amended G.S. 20-16.3(d) in 2006 to provide that the alcohol concentration results from such a test, termed an alcohol screening test by statute, are not admissible in court— not even for purposes of determining probable cause—and may not be relied upon by a law enforcement officer. An officer may rely upon, and a court may receive evidence of, whether the result from such a test was positive or negative. But since a positive result merely establishes the presence of alcohol, and driving after drinking by a person who is over 21 is not a crime, such evidence doesn’t add much proof of impairment.
The court of appeals applied this rule in two cases decided today: State v. Overocker and State v. Townsend. In Overocker, the court concluded that evidence that a defendant smelled “faint[ly]” of alcohol, had consumed drinks at a bar, registered a positive result on a portable breath test and backed over a motorcycle in a parking lot that was parked illegally behind his sports utility vehicle were not sufficient to establish probable cause that the defendant was driving while impaired. In Townsend, the court determined that though the trial court erred in admitting the numerical results of the portable breath test at a pre-trial hearing on the defendant’s motion to suppress, other evidence was sufficient to establish probable cause that the defendant was driving while impaired, and the violation did not entitle the defendant to a new trial.
Somewhat oddly, the alcohol concentration results of a portable breath test are admissible for purposes of establishing probable cause in the one context in which evidence of a positive or negative result would be just as probative, namely to prove any of the several zero tolerance offenses under State law. See G.S. 20-138.2A(b2), 20-138.2B(b2), 20-138.3(b2). It is unclear why the General Assembly amended G.S. 20-16.3 to preclude reliance upon and admission of alcohol concentration results from portable breath testing instruments at pre-trial hearings for other offenses. The amendments were part of an Act that otherwise facilitated the State’s prosecution of impaired driving offenses and broadened the rules governing the admissibility of evidence by, for example, approving the admission of expert testimony regarding the result of a Horizontal Gaze Nystagmus (HGN) test when the test is administered by a person trained in HGN. Presumably the reliability of portable breath test results was the General Assembly’s concern. See, e.g., People v. Aliaj, 36 Misc. 3d 682, 693 (N.Y. Sup. Ct. 2012) (noting that “tests given in the field are prone to multiple possibilities for interference which may not exist at police stations” including varying lighting conditions, radio interference, temperature, and the location’s physical layout).
Former G.S. 20-16.3 (2005), like the current statute, required that tests be made on approved devices and in accordance with applicable regulations and permitted the admission of alcohol concentration results only for purposes of determining probable cause. Other courts have considered those safeguards sufficient. See, e.g., Der v. Connolly, 666 F.3d 1120, 1131 (8th Cir. 2012) (noting that while a portable breath test lacks sufficient reliability to be admitted as substantive evidence, it is admissible to establish probable cause). North Carolina is not, however, alone in further limiting the use of such evidence. See Greene v. Commonwealth, 244 S.W.3d 128, 134-35 (Ky. Ct. App. 2008) (concluding that though the results of a portable breath test are inadmissible to prove guilt or for sentencing purposes, the pass/fail result of a portable breath test is admissible for the limited purpose of establishing probable cause for an arrest at a hearing on a motion to suppress). Whatever the legislature’s reasoning, the limits exist and they unquestionably diminish the probable value of evidence from portable breath tests.
Overocker highlights the effect of this limitation. Though there was no dispute that the defendant in Overocker had consumed alcohol, he showed no outward signs of impairment and performed satisfactorily on field sobriety tests. Indeed, he only came into contact with law enforcement officers because of a traffic accident that was not his fault. Because of the rule in G.S. 20-16.3(d), no evidence appears in the record or was introduced in court of the alcohol concentration result that registered on the portable breath test. One might speculate, based on the officer’s subsequent arrest of the defendant, that the result approached a minimum level of 0.08. If there was in fact such a result, and it had been admitted, one might have expected a different ruling from the trial court. Under G.S. 20-16.3(d), however, the precise results were inadmissible, and the positive result revealed nothing that was not already known, i.e. that the defendant had consumed alcohol. Thus, there was no probable cause for the arrest.