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State Supreme Court Holds That Non-Expert Witnesses May Not Testify as to Whether DUI Subject Was High On Marijuana

This fall, the Massachusetts Supreme Judicial Court considered whether field sobriety tests (FSTs) could be admitted as evidence when a police officer suspects the driver has been driving while under the influence of marijuana. In determining whether a suspect is driving under the influence of alcohol, police typically administer three FSTs — the “walk and turn test,” the “horizontal gaze nystagmus test,” and the “one leg stand test.” These tests were specifically developed to measure alcohol consumption, and there is agreement in the scientific community that a strong correlation exists between insufficient performance on the FSTs and a BAC (blood-alcohol content) of over .08% (the legal limit). By contrast, there is no scientific agreement yet that FSTs, or some FSTs, can determine marijuana intoxication.

In 2016, the Illinois governor signed SB 2228, dictating that drivers will be subject to Illinois marijuana DUI charges only if they have at least 5 ng of THC in their blood, or at least 10 ng of THC in their saliva. Prior to the law, the state could bring DUI charges even when the subject had just trace amounts of THC in their system. This meant that someone who smoked marijuana weeks prior could still test positive and be charged with a misdemeanor. The fact that people could face DUIs for trace THC in their systems “was making a crime without any criminal intent,” said an Illinois public defender.

The new Illinois law did not change the pre-existing law making it a DUI to drive while under the influence of cannabis. At trial, the state must prove by the arresting officer’s expert testimony that the person was impaired due to the consumption of cannabis. As with a DUI for alcohol, a person can be found guilty even if he or she is under the “legal limit” if the court finds that he or she was impaired to the point that he or she was unable to safely operate a motor vehicle.

A legal challenge to this process came before the Massachusetts Supreme Court after Thomas Gerhardt was charged with driving under the influence of marijuana in violation of Massachusetts law. Gerhardt filed a motion for a Daubert-Lanigan hearing, in which the judge decides whether expert testimony is reliable, seeking to challenge the admissibility of the FSTs in a case of marijuana DUI. Following a hearing, the lower court reported four questions to the appeals court:  (1) whether police officers may testify about FSTs in prosecutions for DUI-marijuana; (2) whether the effects of marijuana consumption are sufficiently within the common knowledge of a layperson, such that a non-expert witness may opine about whether a person is intoxicated; (3) whether a police officer, who has not been qualified as an expert witness, may testify regarding the effects of marijuana on a person (such as bloodshot eyes, lack of balance, slow reaction times, paranoia, slow speech, lack of coordination, or relaxed responses); and (4) whether a juror may rely on his own common sense about marijuana, as he is permitted to do in a DUI-alcohol prosecution.

The Massachusetts Supreme Court granted Gerhardt’s application for direct review. It reached the following conclusions on the four reported questions. (1) Police officers may not testify regarding FSTs as they do in DUI-alcohol prosecutions. Police officers, however, may testify regarding administering “roadside assessments.” (2) A lay witness may not opine that another person is high on marijuana. (3) A police officer may testify regarding the effects of marijuana on a person. However, an officer is not allowed to opine that these characteristics indicate the driver is under the influence of marijuana. (4) Jurors can use their common sense in evaluating evidence presented at trial.

In reaching its holding, the state high court explained that the lack of scientific consensus regarding the use of FSTs in evaluating marijuana intoxication does not mean that FSTs have no probative value in DUI-marijuana cases. The court held that to the extent that they are relevant to establish a driver’s coordination, balance, and other skills necessary to safely drive a car, FSTs are admissible at trial as observations of the police officer conducting the assessment. Regarding evidence of officers’ observations of “roadside assessments,” the high court ordered, they should be given without any statement as to whether the driver “passed” or “failed,” and they will not comment on whether the performance suggested impairment. Since the effects of marijuana vary from one individual to the next, and those effects are not commonly known, neither a police officer nor a lay witness is permitted to offer an opinion as to whether a driver was under the influence of marijuana.

The Massachusetts Supreme Court remanded the case to the district court.

Research has shown that red blood cells do not fully absorb THC and that the blood content of THC spikes right after use but then drops off quickly thereafter. Similarly, saliva does not absorb THC well, and testing has not proven reliable. When it comes to blood testing for THC, there is no equivalent to portable alcohol breathalyzers, and experts say portable saliva tests are unreliable. Either way, waiting a few hours to drive after getting high is probably the smartest decision, especially since tests have shown that even the mildest buzz can correlate to blood THC levels well above the legal limit.

If you have been charged with a DUI offense in Illinois, it is crucial to speak to an experienced Illinois DUI lawyer as soon as possible. Harvatin Law Offices, PC provides knowledgeable representation to people in Springfield and throughout Illinois. We have considerable experience defending individuals charged with DUI offenses and representing drivers with revoked licenses before the Illinois Secretary of State. To learn more, and to set up a free initial consultation, contact us online or call us at 217.525.0520.

More Blog Posts:

Washington Supreme Court Holds Random Urine Testing of DUI Probationer is Constitutionally Sound, Illinois DUI Lawyer Blog, November 2, 2017.

State Appeals Court Upholds Polo Mogul’s DUI Manslaughter Conviction, Illinois DUI Lawyer Blog, October 2, 2017.

Ten-Year Court Battle Culminates in Probation for Riverdale Homicide Defendant, Illinois DUI Lawyer Blog, September 1, 2017.

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