Impaired Driving (by Drugs)

  • How Do “Impaired Driving by Drugs” Investigations Work?
  • Penalties for Impaired Driving
  • Common Defences

How Do “Impaired Driving by Drugs” Investigations Work?

If you have been charged with Driving While Impaired by a Drug (other than alcohol or by a combination of drugs and alcohol), the investigation likely proceeded in a different way than the far more common investigation for Driving While Impaired by Alcohol. There are three phases of the investigation:

     Phase I

First of all, at roadside, the police officer, suspecting that your ability to operate a motor vehicle was impaired by a drug, probably demanded that you perform certain physical tests (possibly in addition to providing a breath sample into a roadside screening device). Those tests are:

1.  The Horizontal Gaze Nystagmus Test (“HGN”).  In this test the officer will have you follow a pen or small flashlight with your eyes.  He or she is looking for involuntary jerking of the eye as it moves side to side.

2.  The Walk-and-Turn Test.  Otherwise known as the “Heel-to-Toe” test, you will be instructed to walk heel to toe in a line while following instructions as to number of steps and when to turn.

3.  The One-Leg Stand Test in which you are required to stand with one foot off the ground and count aloud.  The officer is looking to see if you have problems maintaining your balance.

     Phase II

If you did not pass those tests in the opinion of the police officer, he or she would have made a formal demand that you go with them to the detachment and participate in a further series of tests conducted by an officer who is a certified drug recognition expert.  In addition to more “divided attention” tests similar to those just described, the drug evaluation officer would have conducted a physical examination of you including taking your blood pressure, temperature and pulse and checking muscle tone.  The officer may also have examined exposed parts of your arms, neck and legs for signs of intravenous injections.

     Phase III

If, based on the evaluation, the drug evaluating officer had reasonable grounds to believe that your ability to operate a motor vehicle is impaired by a drug or by the combination of alcohol and a drug, the officer may have made a further demand that you provide a sample of your saliva, urine or even blood to be analyzed for the presence of drugs.  In the event a blood sample was taken, it could only have been done by a qualified medical practitioner.

Refusing to abide by any of these demands is an offence, provided the demands are lawful and you don’t have a reasonable excuse for failing to comply with a demand.

What Happens Next?

At the conclusion of the evaluation and any taking of samples, you would have been released upon a Promise to Appear and required to attend court.  You will be required to personally attend court unless you provide instructions to an agent, invariably your lawyer, to appear on your behalf.  The initial appearances are not trial dates – they are pre-trial appearances to determine issues such as disclosure, type of plea and scheduling.  Unless the court otherwise requires it, it is our practice to look after all pre-trial appearances on behalf of our clients without requiring them to attend.

Penalties for Impaired Driving (By Drug)

If you are convicted of Impaired Driving by Drug, the penalties are the same as for normal Impaired Driving.  A first offence carries a criminal record and a minimum one- year driving prohibition. A second offence carries a minimum 30 days in jail and three year driving prohibition. A third offence? A minimum 90 days in jail and a lifetime driving prohibition.  Once any prohibition is over, you will have to pay for and complete the Responsible Driver’s Program.  Unlike the case of Impaired Driving by Alcohol, unless you have a history of alcohol-related Criminal Code offences, you will not have to pay for the installation and monitoring of an interlock (alcohol detection) device.

Common Defences

In cases where your ability to drive is alleged to be impaired by alcohol, breathalyzer evidence is relied upon to prove a charge of “Over .08”.  There is no equivalent charge when it comes to drugs.  The sole charge is Impaired Driving which must be proven by expert evidence.  In other words, just because you are shown to have a drug or chemical agent in your bloodstream does not mean that this caused impairment of your ability to drive.

Your defence to this charge will likely have a number of facets, including the important questions of whether there were proper grounds to make the three demands that were presumably made in the course of the investigation.  If grounds are not shown to make any of these demands, any evidence obtained following that demand may not be admissible to prove impairment.  (Note that the results of the initial roadside test are not admissible to show impairment in any event.)

Assuming that the demands are lawfully made, impairment of your ability to operate a motor vehicle must still be shown.  The reliability of the results of any tests conducted is only as good as the method used to conduct the tests and the expertise of the officer interpreting them.  These areas are generally a key focus of cross-examination in these cases.

The statement above is not legal advice. It is simply intended to give a very general understanding of this offence and some of the possible issues and defences that might be considered in defending it. For legal advice on impaired driving, click here.