When most people imagine a person charged with impaired driving in North Carolina, they think of a person who has a blood alcohol content (BAC) at 0.08 or above, as determined by a breath or blood test. However, a person can be charged with DWI with an unknown BAC, as well as with a BAC below 0.08.
The impaired driving statute in North Carolina is found in G.S. 20-138.1(a) and provides that
A person commits the offense of impaired driving if he drives any vehicle upon any highway, any street, or any public vehicular area within this State:
(1) While under the influence of an impairing substance; or
(2) After having consumed sufficient alcohol that he has, at any relevant time after the driving, an alcohol concentration of 0.08 or more. The results of a chemical analysis shall be deemed sufficient evidence to prove a person's alcohol concentration; or
(3) With any amount of a Schedule I controlled substance, as listed in G.S. 90-89, or its metabolites in his blood or urine.
Therefore, if a person’s BAC is 0.08 or more, that person violates G.S. 20-138.1(a)(2). But a person with an unknown BAC or with a BAC below 0.08 can violate G.S. 20-138.1(a)(1) if they are determined to be “under the influence of an impairing substance.”
The North Carolina Court of Appeals discussed the meaning of impairment in the 1985 case, State v. Harrington. In Harrington, they stated that
"Impairment" does not appear to have any special legal meaning, but simply means "weakening, making worse, diminishment." See Black's Law Dictionary 677 (5th ed. 1979). Under our former "driving under the influence" statutes, the test was whether the accused had "drunk a sufficient quantity of intoxicating beverage or taken a sufficient amount of narcotic drugs, to cause him to lose the normal control of his bodily or mental faculties, or both, to such an extent that there is an appreciable impairment of either or both of these faculties." State v. Carroll, 226 N.C. 237, 241, 37 S.E.2d 688, 691 (1946). The new statute 1983 N.C. Sess. Laws c. 435, s. 24, codified at G.S. 20-138.1, consolidated existing impairment offenses into a single offense with two different methods of proof, but it does not appear to have changed the basic definition of "impaired."
The court of appeals went on to explain that “the statutory BAC is not a sine qua non of DWI.” In fact, “the State may prove DWI where the BAC is entirely unknown or less than” the statutory BAC.
In another 1985 case, State v. Sigmon, the court of appeals upheld a trial court’s conviction of DWI where the defendant’s BAC was below the statutory limit. In that case, the defendant’s BAC was 0.06, but other evidence introduced at trial included a police officer’s testimony “that in her opinion, defendant was under the influence of alcohol.” The police officer based her opinion on her “observation of defendant, defendant's driving on the occasion in question, the odor of alcohol about her person and her inability to perform satisfactorily certain sobriety tests.” The court held that “[t]his constituted substantial evidence, separate and apart from the breathalyzer result, that defendant's mental and physical faculties were appreciably impaired. G.S. 20-138.1(a)(1).” Because there was not sufficient evidence of a per se violation of the statutory limit, the trial court did not err in not instructing the jury on G.S. 20-138.1(a)(2).
More recently, in 2005, the court of appeals looked at the case State v. Wood, where a period of two hours passed between when the officer initially stopped the defendant and when the defendant submitted to the breath test. The breath test results showed that at the time of the test the defendant’s BAC was 0.07. The State attempted to introduce an expert’s testimony using retrograde extrapolation to show that the defendant’s BAC at the time of the stop was 0.10. However, the State did not lay a foundation to show the relevancy of the testimony. The court of appeals upheld the defendant’s conviction of DWI because “[o]ther testimony sufficiently support[ed] the jury's conviction of defendant under N.C. Gen.Stat. § 20-138.1(a)(1) of driving ‘[w]hile under the influence of an impairing substance.’” The other evidence included the defendant’s admission that she had previously consumed alcohol, an open half-filled bottle of vodka in the defendant’s car, the odor of alcohol coming from the defendant’s vehicle, and the officer’s opinion that the defendant’s faculties were appreciably impaired.
In addition to obtaining a conviction under G.S. 20-138.1(a)(1) in cases where the BAC is below the statutory limit, a prosecutor can also turn to G.S. 20-138.1(a)(1) in cases where the BAC is unknown because a defendant refuses a breath test. In State v. Mark (2002), the court of appeals stated that “[t]he opinion of a law enforcement officer... has consistently been held sufficient evidence of impairment, provided that it is not solely based on the odor of alcohol.” In that case, the defendant refused to submit to a breath test after being arrested for impaired driving. The court held that the officer’s opinion that the defendant was impaired, which opinion was based on the performance of field sobriety tests, was sufficient evidence under G.S. 20-138.1(a)(1) to support a conviction.
If you have been charged with impaired driving, contact an attorney at Rosensteel Fleishman, PLLC (704) 714-1450, to discuss your options.