On November 30, 2020, Arizona voters passed Proposition 207, which legalizes purchasing and using marijuana recreationally, for individuals at least twenty-one years old, codified in Arizona Revised Statute §36-2852. (While possession of any amount of marijuana remains a federal crime, federal law enforcement officers don’t make arrests involving personal use amounts of marijuana, and federal courts don’t prosecute personal use cases, but the law prohibiting the possession of marijuana remains a part of the United States Code). As part of this change in the law, the elements of a DUI marijuana charge were changed. Regarding other drugs, both illegal and prescribed, the state only needs to prove that the motorist drove with the drug in their system, and the burden then shifts to the motorist to prove that they were using the drug as prescribed. However, in the case of marijuana, Arizona Revised Statute §36-2852(B) provides that a motorist may be convicted of a DUI based on having marijuana in their system “only if the person is also impaired to the slightest degree.” (Note that while it is illegal for anyone under twenty-one years old to consume marijuana, there is no language limiting the requirement to prove impairment to those twenty-one or older).

This change in the law eliminates any distinction between a DUI impaired charge, and a drug DUI charge, in that the elements are the same – the state must prove that the driver was impaired. This is a significant advantage to a motorist charged with a marijuana DUI, as in every other type of drug DUI case the state does not have to prove anything beyond the presence of the drug in the motorist’s system, shifting the burden to the motorist to prove they were using the drug as prescribed, which, of course, does not provide a defense when the motorist has taken illegal drugs.

In addition, there is no evidence that field sobriety tests demonstrate that an individual is impaired by marijuana use. Our courts fundamentally misunderstand the purpose of field sobriety testing in general, regularly allowing law enforcement officers to testify that errors on the FSTs demonstrate “cues of impairment.”As noted by the National Highway Traffic Safety Administration, the tests are not designed to measure impairment; instead, when the tests were developed, the intent was to “provide statistically valid and reliable indications of a driver’s BAC, rather than indications of driving impairment.” Validation of the Standardized Field Sobriety Test Battery at BACs Below 0.10 Percent, DOT HS 808 839, August 1998, NHTSA, Stuster & Burns, at pp. 27-28.

In the case of marijuana use, scientists and the federal government have repeatedly acknowledged that field sobriety tests do not demonstrate that an individual using marijuana is impaired. “There are currently no evidence-based methods to detect marijuana-impaired driving.” NHTSA Marijuana-Impaired Driving: A Report to Congress, DOT HS 812 440, at pp.12-13. “There was no correlation of number of clues present [when field sobriety test was administered] with the concentration of THC found in the blood.” A 2-Year Study of Δ 9-tetrahydrocannabinol Concentrations in Drivers: Examining Driving and Field Sobriety Test Performance, K. Declues, S. Perez & A. Figueroa, Journal of Forensic Science, Vol. 61, No. 6 (Nov. 2016), at 1667. “[S]tandardized field sobriety tests commonly used to detect driving under the influence of drugs or alcohol were not effective in detecting marijuana intoxication.” Field Sobriety Tests and THC Levels Unreliable Indicators of Marijuana Intoxication, United States Department of Justice’s National Institute for Justice, at p. 3.

If you are using marijuana, be smart about it. Don’t smoke before driving, and don’t smoke while driving, or even while riding in a car. If you are going to drive with marijuana or paraphernalia (pipes, bongs, rolling papers, etc.) in the car, keep them in the trunk and not in the driver’s compartment.