What Can Medical Cannabis Users Do To Protect Themselves From DUI Charges?

A recent article published by Manisha Krishnan for VICE told a harrowing tale. A woman, who uses medical
cannabis to treat her Multiple Sclerosis, was arrested and investigated for impaired driving on the basis of a positive test for cannabis.

​The facts are simple: the woman went out to celebrate her son’s birthday. Before she left, she smoked half a tiny joint. She was pulled over on the way home. She admitted to having one drink, and was given a breathalyser. She passed. She was then asked to do a roadside saliva test for cannabis. The test came up positive for THC.

On the basis of that, she was arrested, taken to the police detachment, and subjected to the Drug Recognition Evaluation Program. Despite her medical condition, she managed to pass the DRE test. She was then released. But not before her vehicle was impounded and she was given a roadside suspension for cannabis use.


Because she had failed the saliva tester and produced a positive reading for THC. Despite the fact that she was clearly not impaired and the police’s own test had demonstrated that, she did not get to go free because of provincial laws  that imposed penalties on the basis of a roadside THC detection.

Never mind the fact that the roadside saliva tester was used in zero degree weather when its operating temperature is 4 degrees Celsius and up. Never mind the fact that she clearly was not impaired by a drug. Because she had failed the roadside test, she was served a penalty.

There are two problems with this. First, how can medical cannabis users protect themselves from DUI charges? And second, why are the police enforcing a discretionary roadside suspension when they know they are not obligated to do so?

Dealing with the latter issue first, one needs look no further than the Immediate Roadside Prohibition scheme in British Columbia for guidance about this. In BC, the Immediate Roadside Prohibition scheme was challenged on the basis of the fact that the scheme effectively served as a replacement for criminal law.

In late 2015, the Supreme Court of Canada finally determined that it did not. The Court ruled that while the police can choose to either issue criminal charges or a roadside prohibition, they were not obligated to do either and any decision made to charge criminally or proceed by way of the administrative penalties was merely discretionary.

I argued, in a companion case to the constitutional challenge, that the police needed more than a roadside breath test result to issue the prohibition. I argued that the law required the police to have reasonable grounds to believe the driver’s ability to drive is affected. The Supreme Court of Canada dismissed those arguments, noting that a requirement for reasonable grounds exists so that the officer has an out in cases where the machine was wrong and they do not want to prohibit a sober person.

Cases like this one.

So if the Supreme Court of Canada has already said that police discretion exists when it comes to roadside suspensions, and this was a case where the police knew they weren’t dealing with an impaired driver why was she punished? She certainly should not have been.

Back when this law was introduced, the police promised that they would use roadside discretion to only enforce it in a sensible way. That medical users who are not impaired would not be impacted under the cannabis impaired driving law, because their subsequent testing would determine who was impaired and who was merely using their medicine in accordance with a prescription.

But that turned out to be a lie. It took the police in this country less than four months of legalization to go back on what they promised would not happen. It took less than four months for a medical user, with a legitimate and serious medical condition, to miss days of work because some device, used outside manufacturer’s specifications said she was impaired, when nothing else said that.

Trust us, they said. They called me cynical.

So what do medical cannabis users need to do to protect themselves from a DUI? And what if this woman had not passed the tests as the police station? What if her MS had a flare-up that caused her to exhibit poor balance and slur her speech such that the police determined she was impaired?

My best advice to medical users is to document as much as possible every dose of cannabis you take. It can be as simple as keeping a little journal with your dosage amount, the date and time you took it, and what (if any) affects you felt afterward. Ensure that you write “TO MY LAWYER” at the top of the document, otherwise it may be seized as evidence against you.

If you are being prescribed your cannabis by a doctor, keep a copy of each prescription. Consider getting a letter from your doctor to the effect that over the number of years you have been taking cannabis, you have taken it in accordance with the prescription and that in the doctor’s opinion you are not using cannabis recreationally. If your doctor is so inclined, see if they will provide a medical opinion that based on your prescription and dosages, you have no impairment including in the ability to drive.

When the police ask you anything about cannabis, always remember to remain silent. Do not lie, but also do not admit to using cannabis. As soon as you make those statements, the police will likely have grounds to ask you to provide samples which will then start the process and expose you to more risk. It may seem awkward and unnatural, but it is what you need to do in order to best protect yourself against an impaired driving charge.

And of course the last thing a medical cannabis user should consider doing if facing a DUI charge is contact a skilled lawyer to challenge the case. Our office is ready and prepared to defend medical users wrongly accused of impaired driving, and wrongfully punished on the basis of bad testing and flawed laws.

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