Every state and the District of Columbia prohibits driving with an alcohol concentration of 0.08 or more though state laws vary regarding whether to establish a violation of the per se impaired driving law an alcohol concentration of .08 or more must exist at the time of driving (see, for example, Ala Code § 32-5A-191; Ark . Code Ann. § 5-65-103; Cal. Veh. Code § 23152(b); Fla. Stat. § 316.193; Iowa Code § 321J.2; Ind. Code § 9-30-6-15; Va. Code Ann. § 18.2-266) or, instead, at the time of testing (see, for example, Ariz. Rev. St. Ann. § 28-1381; D.C. Code § 50-2201.05). Some of the states that base the per se offense on the time of driving presume, subject to rebuttal by the defendant, that a 0.08 result from a chemical test performed within a designated time period after the driving establishes that the person drove with an alcohol concentration of 0.08. Some states have a hybrid system, prohibiting driving with a 0.08 alcohol concentration at the time of driving or within a specified time period after driving (see, for example, Colo. Rev. Stat. § 42-4-1301; Ga. Code Ann. § 40-6-391).
These distinctions in the time of measurement can be significant given that a person’s alcohol concentration, which depends upon the rate at which alcohol is absorbed into the bloodstream and at which it is eliminated from the body, changes over time. Alcohol absorption rates vary depending upon many individual factors including gender, whether a person has had gastric bypass surgery, whether a person consumes food with alcohol, whether a person is a heavy or light drinker, the concentration of the alcohol in the beverage, and even whether the beverage is mixed with regular or diet soda. On an empty stomach, alcohol concentration peaks about an hour after consumption, depending on the amount drunk. Alcohol is removed from the blood at a rate of about 15mg per 100ml per hour, though this rate likewise varies.
In a state that measures its per se impaired driving violations based on a person’s alcohol concentration at the time of driving, a defendant might successfully argue that he or she consumed a large quantity of an alcoholic beverage just before being stopped by police and that the alcohol had not been absorbed into his or her body at the time of the driving. Termed the “big gulp,” or delayed absorption, defense, this argument gave rise to 2004 amendments to Alaska’s impaired driving laws, which now provide that a person is guilty of impaired driving if a chemical test conducted within four hours of driving that detects an alcohol concentration of at least 0.08, regardless of the person’s alcohol concentration at the time of driving. See Valentine v. State, 215 P.3d 319 (Alaska 2009).
North Carolina neither requires the state to prove a defendant’s alcohol concentration at the time of driving nor sets a specific hourly limit in which a chemical analysis must be performed. Instead, G.S. 20-138.1(a)(2) provides that a person commits the offense of impaired driving by driving after having consumed sufficient alcohol that he or she has, at any relevant time after the driving, an alcohol concentration of 0.08 or more. A relevant time after driving is defined as “[a]ny time after the driving in which the driver still has in his body alcohol consumed before or during the driving.” G.S. 20-40.1(33a). As the state supreme court explained in State v. Rose, 312 N.C. 441 (1984), “[a] person whose blood-alcohol concentration, as a result of alcohol consumed before or during driving, was at some time after driving 0.10 or greater must have had some amount of alcohol in his system at the time he drove. The legislature has decreed that this amount, whatever it might have been, is enough to constitute an offense. “ Thus, the big gulp defense is no defense at all to a charge of impaired driving based upon an alcohol concentration of 0.08 or more in North Carolina.
To prove impaired driving based upon a per se alcohol concentration, the state of course must demonstrate that at least 0.08 of the defendant’s alcohol concentration was based on alcohol consumed before or during the driving, which can be a tricky matter when there is evidence that the defendant consumed alcohol after driving. In State v. Ferrell, 75 N.C .App. 156 (1985), the court rejected the defendant’s argument that breath test results were inadmissible given defendant’s admission that he drank several big swallows from a Jack Daniels bottle given to him by the person who picked him up after the accident where defendant also admitted that he had consumed three beers before the accident. The court, however, granted the defendant a new trial based on the prosecutor’s improper questioning of the defendant regarding his failure to testify in district court as part of the State’s effort to establish that the defendant fabricated his post-accident drinking after learning that it was a defense to the impaired driving charge. In a more recent case, State v. Mumford, ___ N.C. App. ___ (No. COA 09-300, January 5, 2010), the court likewise held that the State’s evidence was sufficient for a reasonable juror to conclude that defendant was impaired at the time of the incident where a breath test administered three hours after accident revealed a BAC of 0.09 and defendant admitted to drinking one 32-ounce beer, having a few swallows of another beer, and drinking a shot of liquor in the hours before the accident, despite the defendant’s contention that his alcohol concentration resulted from his drinking of part of a beer after the accident.
Loyal readers, what do you think? Does North Carolina’s relevant time after driving metric reflect legislative ingenuity or something less laudable?