Daubert, marijuana impaired driving, cannabis impaired driving, drugged driving, field sobriety testing, blood THC concentration, expert evidence


Field sobriety and blood alcohol concentration tests are proven reliable techniques to determine whether a person us under the influence of alcohol. No such technique has been developed to reliably determine whether a person is under the influence of marijuana. However, despite a lack of scientific consensus regarding the reliability of field sobriety and blood toxicology tests to determine marijuana impairment, these methods are routinely used as evidence of guilt in marijuana impaired driving prosecutions. Twenty-four states have legalized the recreational use of marijuana, and Florida appears to be set to join them in the near future. As a result of increased access to marijuana, it is logical to assume that the percentage of car accidents involving drivers suspected of marijuana impairment will rise. This comment evaluates the current state of science’s ability to detect marijuana impairment; how different states where recreational marijuana use is legal have addressed the admissibility of field sobriety and blood toxicology tests under the Daubert expert evidence admissibility principles in marijuana impaired driving prosecutions; and recommends that Florida judges exclude such evidence from marijuana impaired driving prosecutions until the underlying science is proven to be reliable.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.