DUI testing has always been a controversial issue for drivers, lawyers, judges, and law enforcement.  The evolution of reliable, accurate technology has taken time to develop -- and the overarching consideration behind the use of said technology is to avoid false negatives and false positives, rendering only consistent, evidence-worthy measurements.  After all, nobody wants to blow twice into a breathalyzer and be given two different numbers.  

Since cannabis was legalized in Washington in 2012, law enforcement fell behind on possessing a reliable device to test for cannabis or other drugs.  The shortfall has left officers with nothing more than observing erratic driving behavior, impaired coordination, and physical cues -- coupled with standard field sobriety tests -- as the primary tool for detecting cannabis or drug impairment, making their case more difficult to prove in a court of law. Law enforcement may also seek a warrant to test a driver's blood for active THC, but results often take weeks to come back.  The warrant requirement to search a driver's blood was upheld by the Supreme Court of the United States in the case of Missouri v. McNeely, where the high court concluded that “the natural dissipation of alcohol in the bloodstream does not constitute an exigency in every case… to justify conducting a blood test without a warrant.”

Cannabis DUI Testing Technology

New machines are currently in development around the country, and even the world, to test for active THC in a more efficient manner and some of that work is underway at Washington State University. Currently, WSU researchers are busy developing a field-capable cannabis breathalyzer system.  Herb Hill, a chemistry professor at WSU, and his colleagues, are working on this device, which will be hand-held allowing officers to detect THC from a driver's breath.  The mechanism at the heart of the device is called “ion mobility spectrometry” -- it functions in a similar way to chemical warfare and explosives detectors employed by the military and airport security.  

Concerns Over Accuracy of Breath-Testing for Marijuana DUIs

Cautiously, Hill explained that initial use of the device would not function as “evidential information.”  Instead, it would act as a screening instrument, providing an officer more ground to stand on when requesting a blood sample.  The risk of wrongful arrest has heavy implications on an individual's personal liberties, so law enforcement wants to make sure that employing such technology will be objectively accurate across the board.  

Some marijuana users are fearful that drivers will be arrested even though they may not be impaired -- as scientific evidence has shown THC to exist in a person's body even though they are no longer stoned.  To combat this risk, companies are developing different methods for testing THC levels including eye-scans, sweat analysis from skin, and saliva tests.  Further testing will need to be conducted to cross-reference the accuracy of these wide-ranging systems.

Looking to Our Distant Neighbors in Colorado for Marijuana DUI Guidance

In Colorado, the State Patrol is engaging in a three-year pilot program where an oral fluid tester is utilized in sampling a driver's saliva for substances including marijuana.  The pilot program requires a driver's consent in order to have their cheek swabbed for saliva.  Five minutes later, an electronic readout provides data on the presence of drugs, including marijuana. In the effort to detect marijuana in a driver's blood, a breathalyzer has one major pitfall -- it cannot detect marijuana consumed in edible form.  

Testing driver's for marijuana is clearly already underway, but only the future can tell us what systems will be the most reliable for proving intoxication.  In the meantime, if you are facing DUI charges for marijuana, alcohol, or other substances, do not hesitate to contact Aaron Wolff, a seasoned DUI defense attorney with 15 years of courtroom experience to effectively advocate for your case.