Like ‘flipping a coin’: Why it’s so hard to test drivers for pot

The federal government plans to invest $81 million to train police officers to smoke out drivers impaired by pot across Canada while using a test experts say is flawed and that is being challenged in a U.S court.

An investigation by The Fifth Estate shows the tests done by police drug recognition experts (DREs) can lead to false arrests, are prone to police bias and according to one scientific expert are no better at detecting drug-impaired drivers than “flipping a coin.”

“You can’t hijack science in the name of law enforcement,” says David Rosenbloom, a clinical professor in the Department of Medicine at McMaster University in Hamilton, Ont.

“We know that with high enough concentrations [of marijuana] in the blood that driving is impaired so it’s not that we don’t need tests of impairment, it’s just that we need valid tests of impairment, and at this point in time we don’t have them.”

The DRE test is a 12-step process that involves examining a suspect’s vital signs, eyes, balance and ability to concentrate and then rendering an opinion.  For Rosenbloom, the science of the test simply is not there.  “It’s equivalent of flipping a coin, it’s 50/50 as to whether we know the person was impaired or not.”

Meanwhile, the American Civil Liberties Union in Georgia recently launched what is believed to be the first civil challenge in the U.S. on behalf of four drivers wrongfully arrested by police officers trained as drug recognition experts.  The ACLU has a warning for Canada.

“I think that Canadian police departments need to think twice about pouring millions or billions of dollars into a failed system that has not worked in the United States,” says Sean Young, legal director for the ACLU in Georgia.  “And the taxpayers of Canada should be outraged that their precious dollars are being wasted on this program that just results in more innocent people being thrown into jail.”

Drug recognition experts have been operating in Canada since the 1990s. However, Canada is set to significantly increase their numbers as marijuana is legalized.

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