Two and a half months ahead of the legalization of marijuana in Canada, Saskatchewan police explained in detail how they lay impaired driving charges against motorists driving while high or under the influence of alcohol.

In order to lay impaired driving charges, police use Drug Recognition Evaluators, officers who have completed a specialized two year training course.

If an officer believes a driver may be impaired by drugs or alcohol, they are first subjected to a field sobriety test. If the driver fails the field sobriety test, they are taken to a police station where a DRE will conduct an evaluation.

“Drug Recognition Evaluators undergo extensive training and use a rigorous, scientific 12-step procedure in performing the evaluation,” Cpl. Brian Ferguson, Provincial DRE Training Coordinator, said. “The evaluation must show impairment, signs and symptoms consistent with one or more drug categories, and the evaluator's findings must be supported by the toxicology.”

Some of the 12 steps in the evaluation include a breath test if applicable, checking pupils, muscle tone and looking for injection marks. If the DRE believes the driver is impaired based on those factors, they can compel a blood or urine test.

If the DRE determines the driver is impaired after the 12 steps have been concluded, an impaired driving charge can be laid.

According to officers, one question that is commonly asked is how police will deal with a driver who may have used marijuana several days before a traffic stop.

“The officer has to see a sign of impairment,” Cpl. Ferguson said. “If you do something two days ago, and it’s not affecting you now, then it’s not going to show up. I’m not going to see it.”

There are currently 74 DRE certified officers in Saskatchewan, and police anticipate they will have 40 more by 2019. Certified officers also have to be recertified every two years.

It costs between $3,000 and $4,000 to train a DRE officer, and Saskatchewan Government Insurance is helping to foot the bill for training. SGI says they have spent $500,000 over the past three years to support DRE training.

According to SGI, results from DRE tests have been recognized as legally binding evidence in court.