With the growing number of states in the US legalizing cannabis for recreational purposes, are law enforcement officers making the correct arrest decision? Studies have shown cannabis does not impair the same as alcohol. Performance on field sobriety tests may not correlate with chemical testing results. This presentation will break down SFST results during a green lab and discuss concerns around prosecuting the cannabis impaired driver based on SFSTs.

Recent trends in cannabis legalization have resulted in an unprecedented volume of research on its effects and how impairment from cannabinoids can be understood and detected. This session will help law enforcement officers, prosecutors, and toxicologists be prepared to understand such research and its implications on the detection of cannabis impairment and prosecution of impaired driving cases. Learners will explore strengths and limitations in research methodology and examples from recent publications, along with previous literature on acute and chronic cannabis intoxication for important context. Critical toxicology limitations in studies will also be reviewed. The conceptual basis of screening tests versus diagnostic tests and appropriate statistical analyses will be discussed, as will the impact of prevalence on positive and negative predictive values, the effect of combining multiple tests on a pseudo-Bayesian approach to investigative judgement, and how these factors are relevant to laboratory evaluation of impairment field tests. Understanding the science, how it is presented, and what limitations apply to research will improve equitable case adjudication and offer insight to criminal justice professionals on how to critically evaluate impairment studies.