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Evidence that level of THC in blood wouldn’t have impaired driver may be admissible in injury case

State v. Joshua J. Luther, 2016AP1879-CR, 5/3/18, District 4 (not recommended for publication); case activity (including briefs)

This is a pretrial interlocutory appeal. Luther is charged with causing injury by driving with a detectable amount of THC in his blood. He wants to present expert testimony that the levels of THC would not have impaired him at the time of the crash–he says he last smoked pot the night before. He argues this evidence can help him meet the statutory affirmative defense in § 940.25(2)(a), (the “even-if” defense) which requires a defendant to show the crash would have happened even if he was exercising “due care” and had no controlled substances in his blood. The court of appeals holds the evidence inadmissible on the record as it stands, but cautions the trial court that if facts emerge supporting the defense, that could change.

On a clear afternoon, Luther pulled his van out from a stop sign and into the path of a motorcyclist who had the right of way. The motorcyclist was badly injured.

The state move to exclude testimony that Luther sought to introduce at trial: an expert witness who would opine that Luther’s blood level of THC was “inconsistent with impairment.” The trial excluded the evidence, evidently believing lack of impairment is never relevant to the “even-if” defense.

The “even-if” defense has two elements: the defendant must show both that the accident would have happened in the absence of drug (or alcohol use) and that it would have happened if the defendant had exercised due care in driving. Luther argues that because the jury, as part of the state’s case, will hear that he had THC in his blood, he is entitled to present evidence that it was a sub-impairment amount to rebut the jury’s likely inference that he was under the influence and thus less likely to have exercised due care.

The court of appeals disagrees, because it concludes the evidence, as it now stands, doesn’t offer enough support for the affirmative defense, making the issue of due care irrelevant.

All that is known is that, on a clear day in the early afternoon, Luther pulled away from his stopped position at a stop sign, proceeded into a crossing lane of traffic that had the right of way, and broadsided a motorcyclist who had been approaching from Luther’s left. As the witness recounted, “when the motorcycle got to the intersection the van pulled out and struck the motorcycle with the front corner of the van.”

The evidence above, even combined with Luther’s lack-of impairment evidence, is not enough to entitle Luther to an even-if-defense jury instruction. The lack-of-impairment evidence might help Luther show that he was able to exercise due care, but it does not supply a reason why the collision would have occurred even if Luther had exercised due care. It follows that there is no reason to think, at this pretrial stage, that Luther will be entitled to an instruction on the even-if defense and, thus, no reason why he would be entitled to present his lack-of-impairment evidence.


The court of appeals rejects Luther’s case law-based argument that the defense requires him to show only that the THC did not contribute to the accident, disagreeing with his reading of State v. Gardner, 2006 WI App 92, 292 Wis. 2d 682, 715 N.W.2d 720, and State v. Turk, 154 Wis. 2d 294, 453 N.W.2d 163 (Ct. App. 1990) (¶¶26-28). It also distinguishes its recent decision in State v. Raczka, 2018 WI App 3, 379 Wis. 2d 720, 906 N.W.2d 722 (2017), saying the defendant there had presented substantial evidence that he acted with due care, and thus was entitled to a jury instruction on the defense. (¶¶38-43).

But the court also rejects the state’s claim that that, in all cases, “[w]hether the defendant was impaired by the controlled substance is not relevant to this affirmative defense.” It relies on a hypothetical provided by the state to illustrate its point:

Imagine that Luther had THC in his system while he drove his van down the highway at a legal speed, and was passing through the intersection with the right of way, when a motorcyclist that had stopped at a stop sign pulled out and drove directly into the van, and the motorcyclist suffered great bodily harm. Luther would have an affirmative defense to a charge of causing great bodily harm while operating with a restricted controlled substance, because he was driving with due care, albeit with THC in his system, and he could not have avoided the crash. Faced with these hypothetical facts, it is not apparent to us why Luther could not present evidence that the amount of the controlled substance in his system was so slight that it would not have affected his ability to act with due care. That is, in the State’s hypothetical, jurors might still reasonably wonder whether Luther would have swerved to avoid the motorcyclist—thus avoiding the injury—if only he had not had a controlled substance in his system.


{ 1 comment… add one }
  • Tom Aquino May 25, 2018, 11:31 am

    While the court notes that in the Raczka case the defendant had shown “substantial evidence” that the defendant exercised due care, this should not be read as requiring the defendant to produce “substantial evidence” to get the instruction. Last year’s supreme court opinion in Steitz reiterated that the burden is only to produce “some evidence” to support a jury instruction. The court here note that the defendant had not produced any evidence that he exercised due care, and I believe used the phrase “substantial evidence” to characterize the evidence in Raczka, not to indicate that the defendant here must produce substantial evidence. At least, that’s what I would argue to the circuit court.

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