POLICE Magazine

FEB 2019

Magazine for police and law enforcement

Issue link: https://policemag.epubxp.com/i/1077915

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Page 18 of 60

16 POLICE FEBRUARY 2019 of the subject. Drivers have lost their licenses and have been given jail time to correct their behavior. Generally speaking a person is considered drunk if they have a .08% blood alcohol concentration (BAC). Most states that have established a line dividing acceptable and unacceptable levels of THC in a person's blood- stream have set the number at five nanograms of THC per milliliter present in that person's blood stream. But until very recently, no technology exist- ed for the detection of tetrahydrocannabinol (THC), which is the psychoactive ingredient in marijuana that impairs motor skills and judgement. Several companies are now nearer to intro- ducing technology that could be put to use by law enforcement in the same way as a tradi- tional Breathalyzer. One such company is Cannabix Technologies (www.cannabixtechnologies.com), a Canadian company that says that it is "working with the Yost Research Group at the University of Florida to develop a cutting edge breath-detection device based upon high-field ion mobility and mass spectrometry." Another offering comes from Hound Labs (www.houndlabs. com), a California company that says that its "solution gives law enforcement an objective way to determine if a driver has recently used marijuana and is therefore within the peak im- pairment window." TRADITIONAL SOBRIETY TESTS Emerging technologies show tremendous promise, but some difficulty will continue to exist even as the offerings of these companies—and presumably, countless others—continue to evolve. For example, unlike alcohol, THC can remain detectable in the blood stream for days or weeks, long after any impairment has passed. Frequent users have some measure of THC in their system all the time, even if they haven't gotten high in days. Further, factors like body weight, tolerance, and the con- sumption of the user could impact an individual's level of so- briety. Some individuals have very little impairment despite consuming copious volumes of the drug, while others might be on another planet despite ingesting a very small amount of marijuana. Any of these things could potentially lead to false-positives, false-negatives, or at worst an avenue of defense that could cast a shadow of "reasonable doubt" in subsequent courtroom proceedings. Keith Graves—a leading drug recognition expert and in- structor of DRE skills—says this is why officers need to contin- ue to use Standardized Field Sobriety Tests at stops where the driver is suspected of having used marijuana. "Officers should continue to use the training they have al- ready received to investigate marijuana DUIs," Graves says. "It's important, though, that they read up on current litera- ture and studies on marijuana influence and to keep seeking training on marijuana DUI investigations. Training is the key. With training, you get experience. With training and experi- ence, you make great cases. What we don't want to see is offi- cers not take action on marijuana DUIs," Graves says. Graves says many drug recognition experts have been saying for years that one can't mea- sure a quantitative level of presumed intoxica- tion by cannabis. "ere was a study done where they looked at people's impairment related to being high- er or lower than five nanograms per milliliter. at study showed that people did poorly on their field sobriety tests under five nanograms per milliliter as well as over," Graves says. A report issued by the AAA Foundation for Traffic Safety concluded, "All of the candi- date THC concentration thresholds examined would have misclassified a substantial number of drivers as impaired who did not demonstrate impairment on the SFST, and would have misclassified a substantial number of drivers as unimpaired who did demonstrate impairment on the SFST." Graves says that at least for the time being, officers should continue to rely on SFSTs, looking for things like red conjunc- tiva, dilated pupils, and nystagmus—a condition in which the eyes make repetitive, uncontrolled movements. Look for sub- jects who have a hard time multitasking. Even as private enterprises continue to develop technology to accurately detect THC levels in drivers, police officers need to keep up with their training on signs of impairment from a wide variety of drugs—both legal and illegal. In the end, the training and experience of American police officers are the most essential elements in ensuring that im- paired drivers are kept off the roads. In the end, the training and experience of American police officers are the most essential elements to ensuring that impaired drivers are kept off the roads. Testing Drivers for Marijuana Impairment PHOTO: POLICE FILE PHOTO: HOUNDL ABS Houndlabs is one of the companies developing a THC detector to measure marijuana intoxication.

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