The key ingredient in marijuana is known as “THC,” which is the component measured when testing for whether someone is above the legal limit. THC metabolites can stay within a person’s system for 30 days after smoking marijuana, leading to issues with roadside tests similar to those that test for blood alcohol levels. For THC, a test may show levels above the legal limit, but it does not necessarily mean the person is currently “impaired,” as he could have ingested the marijuana weeks before taking the test. The so-called legal limit for THC levels is 50 ng/mL. But what does that mean exactly, when a level above that could merely indicate that the person had ingested marijuana 30 days prior to the test? If that is the case, they are clearly no longer impaired and it is an inaccurate depiction of the person’s current ability to function. Whether this type of test result is therefore relevant in a car collision is one question that the Iowa Court of Appeals tried to answer when it issued a decision on March 27.
In Putnam v. Kalber decided on March 27, 2013, the Court affirmed the district court’s holding to exclude evidence of the plaintiff’s THC levels at the time of a severe vehicle collision. The reasoning is based on the thorny issue of timing – the plaintiff, Luke Putnam, could have smoked marijuana just before the accident, or it could have been weeks before and he was completely free of any influence it may have previously had on him. Mr. Putnam’s THC levels were 67 ng/mL, well over the legal limit of 50 ng/mL. For this reason, the defendants, Henry Kalber and his wife Karen, moved the Iowa Court of Appeals to reverse the lower court, arguing that evidence of Mr. Putnam’s high THC level should have been admitted to prove his liability. The collision occurred when Mr. Kalber was attempting to make a left-hand turn in an intersection when Mr. Putnam was going straight in the opposite direction. Mr. Kalber’s car collided with Mr. Putnam’s motorcycle, and Mr. Putnam was severely injured. The lower court found Mr. Kalber 70% at fault and awarded damages to Mr. Putnam.
By affirming the lower court, the Court of Appeals held that evidence of Mr. Putnam’s THC levels at the time of the accident should be excluded as it would be unfairly prejudicial to him if admitted. The Court stated that the chance that the test was detecting marijuana ingested weeks ago rather than right before the accident was too high of a risk to take. If the Court reversed the decision and allowed in evidence of Mr. Putnam’s THC level, they would have set a very far-reaching precedent. THC roadside testing would soon be the norm, and any level above the legal limit would place criminal liability on the person testing positive, and would place civil liability on him as well for any vehicle collision that may occur. All of this liability would neglect to take into account the time frame of THC ingestion, and whether the person was still experiencing impaired function. Perhaps the first issue that needs to be addressed is not how long THC stays within a person’s system, but rather how long it causes impairment. Additionally, while a test may be showing levels that came from ingesting marijuana weeks ago, who is to say that it was not immediately before testing and a contributing factor in an accident? These questions cannot be solved by an arbitrary legal limit for THC levels when that limit serves no actual purpose with regard to accident liability, nor does it adequately protect the public.