Recreational marijuana is now legal in Missouri. How do police officers determine if someone is driving impaired—and how does that charge play out in court?

The Defense attorney Travis Noble recently wrapped up a two-week jury trial, a DWI case that he calls possibly the worst he’s seen in his 35-year career. His client was charged with a DWI felony after a car crash that killed a young couple and their infant. The defendant was traveling 107 miles per hour when he hit the other car; a blood test revealed his blood alcohol content was more than double the legal limit. “It was the most horrific thing I’ve ever seen,” Noble says. “And the jury found him not guilty of the DWI.” Noble was able to introduce doubt into the jurors’ minds that his client’s blood sample was handled correctly.

Noble has tried more than 200 DWI cases, and 95 percent of them are alcohol related, he says. But the occasion for this interview with SLM is a potential uptick in a different type of DWI case: those that are marijuana related. By the time you read this, it’s likely that recreational marijuana will be available at your local dispensary. It raises the question: If more people choose to smoke up or consume edibles and then drive, how do police officers determine that someone is driving impaired—and how does that charge play out in court?

–

-

Sergeant Tracy Panus, a public information officer with the St. Louis County Police Department, says county police officers will be prepared if they see an uptick in drivers under the influence, be it marijuana, alcohol, or prescription drugs. It’s illegal to drive impaired, even if the substance was prescribed, she points out. When someone is pulled over because they’re, say, driving 20 mph under the speed limit, Panus says police officers will assess the driver’s condition and administer different field sobriety tests based on what drugs they’re suspected of taking. The county also has four specially trained drug recognition experts who can be dispatched to scenes to assist.

Later, in court, defense attorneys like Noble will often dissect what happened at the scene. One defense that Noble sometimes employs is based on the nature of marijuana itself. “Let’s say police pull a car over, and the driver rolls the window down, and it looks like a Cheech & Chong movie: Marijuana smoke pours out of the window,” he says. “Police say, ‘I think you’re under the influence of marijuana.’” The suspect takes a blood test, and the results show that they have a certain level of nanograms of delta-9 THC in their bloodstream. “Well, if you smoke marijuana on Monday, by Wednesday it is still going to be in your system,” Noble says.

Fast Fact

According to the CDC,  marijuana is the most commonly used drug in the United States, with 48.2 million people using it at least once a year.

Police would still have to put together cases based on observations, and Noble has a defense strategy for those observations, too. He’ll look for mistakes that police make in administering field sobriety tests. “Let’s say someone is going 15 miles per hour in a 45-mile-per-hour zone,” Noble says. “He’s slurring his words, his eyes are bloodshot and watery, and he’s stuffing Taco Bell down his throat.” Police might ask him to take the one-leg-stand test. As the driver stands with one foot lifted 6 inches off the ground, they must count while the police look for swaying, lifting arms for balance, putting a foot down, or hopping. If they observe someone doing two of those four actions, it’s indicative of impairment. But certain people—those who are 50 pounds or more overweight; those 65 years old or older; or people with ankle, back, hip, knee, or inner ear issues—aren’t candidates for that test, Noble says. Sometimes, when asked in court, police don’t know those guidelines—and if they don’t, then in some cases, Noble can argue they didn’t know whether his client fit into one of those disqualifying categories and the test isn’t valid.

Why is Noble giving away such defense strategies? Because he does so regularly to the police, he says. Before he was an attorney, Noble was a police officer. Once he became a lawyer, he offered to teach police officers how to correctly administer field sobriety tests and to give them information on how defense attorneys would attack DWI cases in court. “I think drinking and driving is horrible,” he says. “If some drunk hits one of my daughters, I want the police officer who shows up to do it right so the guy goes to jail.” Police departments across the state have taken him up on his offer.

For what it’s worth, Noble doesn’t think the new law legalizing recreational marijuana in Missouri will motivate people who weren’t already smoking to start.

But he adds a startling observation: More so than people driving high on marijuana, he thinks you should be concerned about people driving while on prescription medication that slows their reaction time. “It’s probably a bigger problem than heroin, cocaine, and marijuana combined,” he says.