Proving the Per Se Prong of Impaired Driving without a Chemical Analysis

The usual way for the State to establish that a person drove while impaired under the per se prong of G.S. 20-138.1 is to introduce the results of a chemical analysis demonstrating that the person had an alcohol concentration of 0.08 or more at any relevant time after the driving. Not only are the results of a chemical analysis “deemed sufficient evidence to prove a person’s alcohol concentration,” but they also may be admitted at trial without the foundation required for similar types of scientific evidence.  G.S. 20-139.1. Not just any test of a person’s breath, blood or bodily fluid, however, constitutes a “chemical analysis.” G.S. 20-4.01(3a). To qualify, the test must be performed in accordance with G.S. 20-139.1.

A breath test “administered pursuant to the implied-consent law,” and performed in accordance with rules of the Department of Health and Human Services (DHHS) by a person with a current DHHS permit for the type of instrument employed is an admissible chemical analysis. G.S. 20-139.1(b). A blood or urine test likewise is deemed an admissible chemical analysis if: (1) a law enforcement officer or chemical analyst requested a blood and/or urine sample from the person charged; and (2) a chemical analysis of the person’s blood was performed by a chemical analyst possessing a DHHS permit for the type of analysis performed. G.S. 20-139.1(c4). Before it was amended by the Forensic Sciences Act of 2011, G.S. 20-139.1(c2) required that a test of blood or urine be performed in accordance with rules or procedures adopted by the State Bureau of Investigation, or by another laboratory accredited by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB). For offenses committed on or after March 31, 2011, such tests must be performed by a laboratory that is accredited by an accrediting body that requires conformance to forensic specific requirements and which is a signatory to the International Laboratory Accreditation Cooperation (ILAC) Mutual Recognition Arrangement for Testing.

The State is not limited, however, to proving a defendant’s alcohol concentration by means of a chemical analysis performed in accordance with G.S. 20-139.1. Instead, the State also may prove a defendant’s alcohol concentration by introducing the results of other reliable tests showing the presence of a controlled substance. G.S. 20-139.1(a). One circumstance in which the State might rely upon a test that is not a chemical analysis occurs when a defendant is hospitalized after an incident of suspected impaired driving and his or her blood or urine is analyzed for purposes of medical treatment.  In such a case, testing is performed pursuant to hospital laboratory procedures rather than the procedures required by G.S. 20-139.1. In State v. Drdak, 330 N.C. 587 (1992), the state supreme court determined that the trial court did not err by denying the defendant’s motion to suppress blood test results from a hospital laboratory proffered by the State at defendant’s trial on impaired driving charges to prove his alcohol concentration. The court characterized the defendant’s contention that the blood test results were inadmissible because the test was not performed in accordance with the procedures set forth in G.S. 20-16.2 and G.S. 20-139.1 as “fl[ying] squarely in the face of the plain reading of [G.S.20-139.1(a)],” id. at 592, which states that “[t]his section does not limit the introduction of other competent evidence as to a person’s alcohol concentration or results of other tests showing the presence of an impairing substance, including other chemical tests,” G.S. 20-139.1(a).

Of course, results of tests performed outside the scope of implied consent laws are not afforded the presumptive admissibility of chemical analyses satisfying the requirements of G.S. 20-139.1. Instead, the State must provide a proper foundation for the introduction of such results, including demonstrating their reliability.

The Drdak court determined that the State established a proper foundation for introduction of hospital blood test results by showing, among other facts, that “the hospital’s blood test was performed less than an hour after the defendant’s car crashed into the tree, that an experienced phlebotomist withdrew the blood sample under routine procedure pursuant to the doctor’s orders, and that a trained laboratory technician analyzed the blood sample using a Dupont Automatic Clinical Analyzer which was capable of testing either whole blood or serum.” Id. at 607. The court of appeals in State v. Mac Cardwell, 133 N.C. App. 496 (1999), likewise concluded that the trial court, in denying defendant’s motion to suppress evidence of hospital blood test results in an impaired driving trial, did not abuse its discretion in determining that the Dupont ACA Star Analyzer (“Analyzer”) used by the hospital to measure the defendant’s alcohol concentration was a “reliable scientific method of proof.” Id. at 506. The Mac Cardwell court further noted that the trial court properly allowed the defendant to present evidence to the jury attacking the reliability of the Analyzer and defendant’s results. Id. at 507.

Hospital laboratories sometimes calculate a patient’s plasma-alcohol concentration rather than the alcohol concentration in whole blood. To prove a specific alcohol concentration based on such results, the State must provide testimony from an expert capable of converting the results to grams of alcohol per 100 milliliters of blood in order to prove that the defendant had a specific alcohol concentration. See G.S. 20-4.01(1b) (requiring that the concentration of alcohol be expressed either as: “a. Grams of alcohol per 100 milliliters of blood; or b. Grams of alcohol per 210 liters of breath.”). The Mac Cardwell court held that the trial court did not abuse its discretion in finding the conversion ratio of 1 to 1.18 utilized by a forensic chemist at the SBI laboratory reliable. 133 N.C. App. at 506-07. As it had with respect to the test results, the court noted the propriety of permitting the defendant to present evidence attacking the conversion ratio used by the State. Id. at 507.

Have you litigated a case involving the introduction of hospital blood test results? Was there a battle of the experts? Did the court adopt the 1 to 1.18 ratio or some other formula? Please share your thoughts on these and any other issues related to this post.

4 thoughts on “Proving the Per Se Prong of Impaired Driving without a Chemical Analysis”

  1. What about tests for other potentially impairing substances such as prozac, valium, percocet, zanex, etc.? I have a case coming up with a 76-year-old female client who took one zanex a little before 9 a. m. She had some facial cosmetic surgery that morning in a physician’s office. She says they used topical anesthetics on the places where they operated — no shots or pills.

    She was in a fender-bender wreck at 1 p. m. and charged with DWI. A blood sample was sent to the SBI lab. No results yet. Her zanex prescription says two tablets every four hours. She had one four hours earlier.

    Are there any cases dealing with prescription medications?

  2. See State v. Highsmith, 173 N.C. App. 600 (2005) (rejecting defendant’s claim that evidence was insufficient to establish that he knowingly consumed an impairing substance, stating that “[d]efendant knew or should have known that a prescription medication such as Floricet could impair him, and was thus on notice that, by driving after taking Floricet, he risked cross[ing] over the line into the territory of proscribed conduct” (internal quotations omitted)).

  3. Mr. Mooney, Unfortunately, prescription drugs being the impairing substance only provide a mitigator in the equation rather than a defense.

    Generally, the best success I have had with hospital blood tests or records not being allowed into evidence are when there is no records custodian or affidavit of such custodian to authenticate the records. It is certainly worth looking through what the state has from the hospital in order to see if this is the case.

  4. I have seen cases where police did not test the defendant but the hospital did. The defendant did not think they were over the limit and allowed to police to view the results which were then used in court.


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