Arizona Marijuana DUI trials have become battles over the science of THC and impairment.
In 2020 Arizona ballot Proposition 207 dramatically changed the issue for Marijuana DUI trials. Under the old law if the defendant had active THC within their body (usually proven through blood testing), they were guilty as a matter of law unless they had a valid Arizona Medical Marijuana Card (AMMA), were using the marijuana for the particular medical purpose the card was issued for, and they could prove the THC within their body was below the level which would cause impairment. The problem for defendants was that unlike the .08% standard for alcohol, there were, and are, no valid scientific studies which show at what level people are impaired by THC. Thus, a defendant AMMA holder was guilty unless they could show they were below a level which scientifically does not exist.
Proposition 207 changed two elements of the law. First, any person at least 21 years old can now have active THC in their body and so no one is automatically guilty if they have active THC in their body. Second, a defendant no longer has to prove they are below the impairment level (which does not scientifically does not exist) but rather the prosecutor must prove beyond a reasonable doubt, the defendant is above the non-existent impairment level. In short, the defendant no longer has to prove anything, it is all on the State (see 36 A.R.S. § 2652.B).
To get around this problem for prosecutors some states, such as Washington and Colorado, have enacted what are known as Per Se laws which automatically make the driver guilty if their THC levels are above a certain limit even though the driver may or may not be impaired, like the 08% alcohol limit in Arizona. Proposition 207, Section 7.1, however prohibits the Arizona Legislature from creating similar Per Se limits unless and until the scientific evidence is conclusive on that limit and further, that the National Highway Traffic Safety Administration (NHTSA) recommends the adoption of that Per Se limit. So, in short, Arizona prosecutors now have a lot harder problem proving a defendant is guilty of Marijuana DUI than of an Alcohol DUI.
To try to get around this problem prosecutors like to tell juries the person who tested the blood sample (known as a criminalist) is an expert in the scientific field of THC impairment and so can tell at what level and under what circumstances a person is impaired by THC. To back up their opinion’s criminalists like to cite scientific studies which they claim back up their opinion. The problem with this is although many studies may appear superficially to be good, in reality many are not. If the defendant’s attorney is not familiar with these studies, they may not be able to correctly point out to the jury why the studies the criminalist claims are valid, are in reality not valid. If the defendant’s attorney cannot defend against these scientific studies the defendant will be found guilty of DUI.
Recently a very important article was published by eminent experts in the field of THC impairment. The experts are professors at the Yale University School of Medicine. In the article the experts explain the limitations on many studies which criminalists might cite and why scientifically there is no evidence everyone is impaired by the presence of THC. The article is in effect a blueprint on how to counter the prosecutor’s evidence. If the defendant’s lawyer is familiar with this article, they can use the article to counter the prosecutor’s argument that scientific evidence shows the defendant was impaired. If the defendant’s lawyer is not familiar with the scientific studies they are at a real disadvantage and the defendant will lose the battle over science.
Gordon Thompson
For more information about Arizona DUI and criminal law issues please contact Gordon Thompson who has used his experience to write a blog on topics of interest. You can also chat with Gordon about your specific questions.
Website: https://www.GordonThompsonAttorney.net
Blog: https://www.GordonThompsonAttorney.net/blog/
