Tuesday marked an historic day in Washington, as the first legal marijuana shops opened for business. Now, DUI officers in Seattle and across the state are watching to see whether those cannabis customers get behind the wheel.
Officer Mike Lewis has been with the Seattle Police Department for 25 years. He currently works on the DUI squad, patrolling the streets every night looking for impaired drivers.
"If you're going to consume alcohol, don't drive. If you are planning on smoking or ingesting marijuana, don't drive," he said. "It's the only safe thing to do."
During Lewis' shift on Tuesday, he drove past Cannabis City, Seattle's first legal marijuana shop. He says the crowd in line at the store tells him it's going to be a busy few weeks and months for DUI officers.
It's not that he's never seen marijuana impaired drivers on these roads or even arrested them. Lewis says the Seattle Police DUI Squad noticed an uptick in both, ever since Washington voters approved Initiative 502, back in 2012.
Every time he pulls over a marijuana impaired driver, the excuse is the same.
"Protesting, they say 'but it's legal'," he said. "Well yeah, it's legal to possess in personal amounts, legal to smoke in private, but it's not legal to get stoned and behind the wheel of a car."
He believes that officers will start seeing many more DUI's during the day, as a result of the marijuana retail sales now being legal.
"They're daily consumers," he said. "And I expect that is going to be a trend."
His other concern is that the THC levels in the marijuana found in shops now opening up are likely much higher than the "backyard marijuana" people might be used to.
For now, he's keeping his eyes peeled for signs of impairment.
"The most obvious of course would be the smell," he said. "But they're also going to run stop signs, they're going to have the same lane travel issues as drivers impaired due to alcohol."
If someone gets high off of edibles or another form of cannabis, Lewis admits, that odor wouldn't be present. That's when officers must rely on field sobriety tests.
For drivers, a DUI arrest for marijuana impairment will also likely result in a search warrant, so that officers can take a sample of your blood and test its for traces of marijuana or other drugs.
Courtney Popp is the Washington State Traffic Resource prosecutor, and worked with law enforcement across the state to train them for this day, the day when retail marijuana sales became legal.
While a lot of the signs of impairment are the same as a driver under the influence of alcohol, there are a few more specific things to look for.
"We ask officers to identify whether they notice any eyelid tremors, that's a common sign or symptom," she said.
She says she's confident officers are trained to identify and arrest marijuana impaired drivers. That's not her biggest challenge as a prosecutor.
"The biggest problem we're having statewide is just that the juries don't understand or don't seem to be too concerned with people that are driving under the influence of marijuana," said Popp.
Both she and Officer Lewis predict the number of marijuana-related DUI's will climb over the next few weeks and months.
904 people bought marijuana from Cannabis City on its opening day, Seattle's only legal marijuana shop so far.