The Twelve Weeks of DRE-mas: Interview of the Arresting Officer

Last week, we talked about idiot-proofing in the DRE test. This week, we address another step in the Drug Recognition Evaluation that is designed to make sure the police do not completely bungle the test. This is known as the interview of the arresting officer.

In many cases, though not all, the person who makes the arrest of a supposed impaired driver is not trained in the Drug Recognition Evaluation program. As a result of the lack of training, this person cannot administer the test and another officer must be summoned to do it. This will be common in Canada, as after cannabis legalization we will still have very few trained officers in Canada.

So the interview is a very important step.


In the interview with the arresting officer stage, the evaluating officer is required to ask the arresting officer about the driving behaviour, the appearance of the driver, and their behaviour. Essentially, the DRE officer is asking to borrow the observations of the arresting officer to add to their grounds and the framework of material before them.

This may seem like a logical step. It may seem good that a person conducting an evaluation have all the facts. But the DRE officer is not reviewing the police dash cam video to see what really went down at the roadside. Instead, they are getting a skewed interpretation of events from a person who has already made their mind up that the driver is impaired by a drug.

What this means is that the information conveyed to the DRE officer is likely to be skewed to justify the arrest, rather than to undermine it or present all the facts. There is no obligation on the DRE to cross-examine the arresting officer, or to ask about mitigating factors. Balance poor? Doesn’t matter if you ask what type of footwear the person was wearing. Slurred speech? That the driver was sucking on a penny is irrelevant.

And so what you get is a retroactive justification of symptoms of impairment, rather than a full picture of the events. It would be helpful if the training required these types of inquiries, or if police were trained to present inculpatory and exculpatory information to the DRE officer when laying out the foundation for arrest, but alas. That would be too much justice.

Look, I’m not saying that police are liars and skew the truth in order to best support their version of events. I’m saying that police are human beings and are going to do what we all do when questioned by someone who is more senior to us. The arresting officer in these cases is subordinate to the DRE, and as such there is a power imbalance. It is only natural to justify yourself when questioned about a decision by a superior.

This step of the DRE evaluation preys on human nature with the goal of crafting impairment where there may not be any at all. It is designed to trick police, and not to support reliable results. It is designed to guarantee a conviction and not to identify the innocent.

Whenever possible in a DRE case, it is useful to get the video of the police officers at the detachment, discussing the observations roadside. Deviation from those behaviours at the station may suggest untruthfulness on the part of the officer, while the absence of them may signal an officer who is exaggerating, even unintentionally. A good impaired driving lawyer will be able to cross-examine the investigating officer and the DRE officer and poke holes in the information on which the DRE was predicated.

This is why you need a good lawyer who understands the DRE testing if you are facing an impaired driving charge involving drugs.

To read the first post in this series on Drug Recognition Evaluation, click here. A new step is published every Thursday leading up to legalization of cannabis.

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