Once the interview of the arresting officer is done, the DRE officer is armed, largely, with the knowledge needed to start the evaluation. After all, they've already been told what the subject said and did and therefore are aware of what to look for. So at this stage the DRE officer conducts a preliminary examination and takes the first in a series of pulses.
This is the step designed to create a chaotic baseline so that impairment can be inferred.
According to the training, the purpose of the preliminary examination is to determine whether the person is suffering from any injury or medical condition unrelated the use of drugs (or that will point to the drugs that might be at play.) Of course, as we have already covered in this series, the DRE officer is not a doctor and is not capable of making any type of medical diagnosis of injury or health condition. Even doctors have trouble with this.
Funny story: one time, I went to the doctor because there was a listeria outbreak and I was displaying all the symptoms. My visit to the doctor culminated in a presumptive conclusion that I had meningitis. I was sent to the emergency room, where a series of scans and blood tests were conducted, none of which ruled out meningitis. And I kept getting sicker. After two visits, I resigned myself to the fact that I would have to have a spinal tap to determine what was going on. And as I explained my ordeal to my mother, by text message, as she was in China, I was trying to spell subarachnoid hemorrhage. She corrected my spelling, likening it to spiders. I told her that I had a spider bite on my back and that is how I ended up diagnosed with Shingles. Two doctors, one nurse, and still it took days.
So a ten minute examination is not the mechanism to rule out anything but drugs.
Now, a properly trained DRE is supposed to ask the subject a series of questions about health, eating habits, alcohol and drug use, and prescriptions. This seems to make sense. However, in Canada because drivers cannot be compelled to give information to police this step is not required. Instead, under the modified Canadian version of the DRE, the preliminary examination consists only of three things: measuring the pulse, determining whether pupils are of equal size, and whether the eyes have even tracking.
These, of course, are not examinations that can or even could rule out medical conditions. Though I would say that unequal pupils is a surefire sign of a serious head or brain injury that could explain these symptoms. Police will say that it is probably drugs.
In order to check pupils and eye tracking movements the DRE officer will engage in a truncated version of the Horizontal Gaze Nystagmus test, which will be done in more detail in the next stage of the evaluation. This involves a series of specific tests tracking the pupil's ability to follow an object, the ability of the eyes to converge, and to determine whether there is any involuntary jerking of the eyes, which is known as nystagmus. Oftentimes this will be a repeat of the test done roadside, so defence lawyers should always look for differences between the roadside test and the second test, as these may suggest one or both officers did not administer it properly.
After this is completed, the DRE officer then takes the subject's pulse. This is the first of three times that pulse rate is measured. The hope is that people will have higher pulse rates, likely caused by the stress and anxiety of being in police custody and without knowledge of everything that is about to happen, and then this can be used to point to a class or category of drug. But as we all know, heart rate is also linked to anxiety and exercise level and physical health. So it says very little.
After this, it's on to the more intensive eye examinations. By now, you should be noticing a trend. Each time a step is done, it's done again later on. The reason for this is to get multiple points of data, so those that support drug use can be relied on and those that do not can be rejected as "anomalies" or "outliers."
Like I said, this test is designed so that people fail it.
Tune in next week to read Step Two!
Vancouver Criminal Lawyer with a focus on impaired driving, marijuana legalization and related issues, and immediate roadside prohibition defence.