Proving Drugged Driving

Drunk driving has long been a phrase in the national lexicon of terms related driving and public safety. Over the past decade, a companion term—drugged driving—has entered into common usage as policy makers have focused their attention on reducing the incidence of driving while impaired by substances other than alcohol.

The problem, of course, is not new. North Carolina law has long prohibited driving while under the influence of an impairing substance. See G.S. 20-138.1(a)(1). The term impairing substance is broadly defined to include the following substances:

  • Alcohol;
  • A controlled substance under Chapter 90;
  • Any drug or psychoactive substance capable of impairing a person’s physical or mental faculties; or
  • Any combination of these substances.

G.S. 20-4.01(14a).  Thus, prescription as well as illicit drugs may qualify as impairing substances as may over-the-counter medications and other psychoactive substances, like inhalants, depending upon their potential effect on the body. The fact that person is legally entitled to use a particular drug is not a defense to a charged of impaired driving, see G.S. 20-138.1(b), though it may be a mitigating factor at sentencing, see G.S. 20-179(e)(5).

A person is considered to be under the influence of an impairing substance when the person’s “physical or mental faculties, or both, are appreciably impaired” by the substance. G.S. 20-4.01(48b).

How does the State prove that a person was appreciably impaired by an impairing substance other than alcohol?  While no particular form of evidence is required, “evidence of some impairing substance is essential . . . by some means.” Ben F. Loeb, Jr. and James C. Drennan, Motor Vehicle Law and the Law of Impaired Driving in North Carolina 78 (2000 ed.). The State does not have to prove the specific drug consumed.

Drug Recognition Expert combined with chemical analysis. In the State’s ideal case, it would elicit testimony from an officer certified as a Drug Recognition Expert (DRE) regarding the defendant’s impairment and its cause along with testimony from a chemical analyst corroborating the DRE’s conclusions. In many cases, however, no DRE will be available to examine the defendant. The results of a chemical analysis, standing alone, may be inconclusive. The analysis may not reveal how recently the substance was ingested or the level of concentration of a particular drug. In addition, the chemical analyst may lack the necessary expertise to testify about the impairing effects of a particular substance.  (If I’ve overstated the limitations of a chemical analyses or the expertise of forensic chemists in the preceding sentences, I trust that more informed readers will set me straight.) Fortunately for the State, it can establish impairment by drugs in a less ironclad way.

Opinion testimony from experienced officer. In State v. Lindley, 286 N.C. 255 (1974), the state supreme court held that the trial court in an impaired driving case properly allowed a patrol officer with five years’ experience to testify that in his opinion the defendant was under the influence of some drug. The officer in Lindley stopped the defendant for erratic driving. When the defendant got out of his car, the officer saw that he was unsteady on his feet, the pupils of his eyes were contracted nearly to pinpoints, and there was a white substance on his lips. Two passengers in the car were in the same condition. The officer smelled no alcohol on the defendant, who subsequently performed poorly on dexterity tests and appeared to be in a mental stupor. The officer ruled out other causes of the defendant’s condition by asking whether he had diabetes, had physical defects, was sick, limped, had been injured, had seen a doctor or dentist lately, or had taken any medication. The defendant answered no to all of these questions. Based on this knowledge, the officer concluded that the defendant was under the influence of a drug. The state supreme court held that the officer was competent to express that opinion as he was better qualified than the jury to draw inferences and conclusions from what he heard. The court also held that the State’s evidence, which consisted solely of the officer’s testimony, was sufficient to establish a prima facie case.

Defendant’s admission corroborated by expert testimony. State v. Highsmith, 173 N.C. App. 600 (2005) illustrates another manner in which the State might establish impairment by drugs. After an officer stopped the defendant in Highsmith for erratic driving, the defendant said he was on the way home from the dentist and had taken a pain medication known as Floricet.  The officer testified that the defendant’s movements were sluggish and his speech was slurred, but that he did not smell alcohol. At trial, the officer testified to his observations and the defendant’s statements. The State also elicited testimony from an expert in pharmaceuticals, who testified that Floricet was an impairing substance and that a healthcare professional should have warned the defendant of its effects.  The court of appeals held that this evidence was sufficient to establish that the defendant drove while under the influence of an impairing substance.

Even given the variety of ways that the State can prove drugged driving, it seems to me that proving impairment by drugs is significantly more difficult than proving that the defendant violated a per se prong of the impaired driving statute (0.08 alcohol concentration or presence of Schedule I controlled substance) or that a defendant was appreciably impaired by alcohol.

Have you litigated many cases involving allegations of drugged driving? If so, let us hear from you about methods for proving and defending against such allegations.