Proof of Impairment by Drugs

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General Principles

See also: Proof of Impairment by Alcohol

The standard to proving impairment by drugs is the same as impairment by alcohol. The main difference involves the manner of detecting the presence of drugs and presenting evidence that there is impairment.

The investigation of an impaired by drugs case commences with the initial investigation wherein an officer forms a reasonable suspicion of impairment by drugs.

Under s. 254(3.1), the officer may demand that the driver submit to screening test to determine if there is reasonable grounds to believe that the driver is committing an offence under s. 253 regarding drugs:

253.
...
Evaluation
(3.1) If a peace officer has reasonable grounds to believe that a person is committing, or at any time within the preceding three hours has committed, an offence under paragraph 253(1)(a) as a result of the consumption of a drug or of a combination of alcohol and a drug, the peace officer may, by demand made as soon as practicable, require the person to submit, as soon as practicable, to an evaluation conducted by an evaluating officer to determine whether the person’s ability to operate a motor vehicle, a vessel, an aircraft or railway equipment is impaired by a drug or by a combination of alcohol and a drug, and to accompany the peace officer for that purpose.
Video recording
(3.2) For greater certainty, a peace officer may make a video recording of an evaluation referred to in subsection (3.1).


...


CCC

The investigating officer will generally have a Drug Recognition Expert (or Drug Recognition Evaluator) attend the scene of the investigation to perform a Standardized Field Sobriety Test (SFST) to determine if the driver may be impaired by drugs.

If the driver presents sufficient indicia of impairment then they will be given a demand to attend the police station to undergo the full 12 step assessment as set out in the Regulations.[1]

Form of Demand

The officer must issue a demand such as the following:[1]

I demand that you submit to an evaluation, conducted by an evaluating officer, to determine whether your ability to operate a motor vehicle is impaired by a drug or a combination of a drug and alcohol, and that you accompany me for this purpose. Do you understand?



  1. R v Forgarty, 2015 NSCA 6 (CanLII) at para 11

Standardized Field Sobriety Test

The Standardized Field Sobriety Test will frequently take place at the roadside, when it is safe to do so and where the officer has not already formed the requisite grounds to believe that an offence under s. 253 has been committed.

The SFST will involve the examination of the driver's eyes for signs of Horizontal Gaze Nystagmus, a heel-to-toe walk, and a one-legged standing test.

Drug Assessment

The Drug Recognition Expert follows a 12 step assessment process that is generally uniform across all of North America.[1]

  1. Breath Alcohol Test
  2. Interview of the Arresting Officer
  3. Preliminary Examination and First Pulse
  4. Eye Examination
  5. Divided Attention Psychophysical Tests
  6. Vital Signs and Second Pulse
  7. Dark Room Examinations
  8. Examination for Muscle Tone
  9. Check for Injection Sites and Third Pulse
  10. Subject’s Statements and Other Observations
  11. Analysis and Opinions of the Evaluator
  12. Toxicological Examination
CNS Dep. Inhalants PCP Cannabis CNS Stim. Halluc. Narc./Analg.
HGN Y Y Y N N N N
VGN Y Y Y N N N N
LOC Y Y Y Y N N N
Pulse Lower Raised Raised Raised Raised Raised Lower
Blood Pressure Lower Raised Raised Raised Raised Raised Lower
Body Temp. N N N Y Y Y Down
Muscle Tone Flaccid Flac./Norm. Rigid Normal Rigid/Tremors Rigid Flaccid
Key Duration

HGN = horizontal gaze nystagmus
VGN = vertical gaze nystagmus
LOC = lack of ocular convergence

CNS Depressants:

  • Anti-anxiety / traquilizers
    • Xanax/Alprazolam
    • Valium
    • most drugs ending in -pam
  • Anti-Depressants
    • Wellbutrin
    • Lexapro
    • Paxil
    • Zolof
  • GHB
  • Barbiturates

CNS Stimulants:

  • Cocaine

Analgesics:

  • Heroin
  • Oxycontin
  • Demerol
  • Codeine

Cocaine (CNSS):

  • Effect: 30-40 minutes (smoking) 60-90 minutes (nasal)

Detection

  • Urine: 12 hours post dose. Benzoylecgonine metabolite present for 3 days
  • Blood: 5-6 hours after dose

Methamphetamine:

  • Effect:2-8 hours

Detection

  • Blood: 1-3 days
  • Urine: 1-5+ days

THC (Cannabis):

  • Effect:2-5 hours

Detection

  • Blood:3-4 hours post dose
  • Urine: several days or weeks

PCP:

  • Effect: 4-6+ hours

Detection

  • Blood: 1-3 days
  • Urine:3-7+ days

See: [1]

Opinion of Impairment by Drug

There is no need for a "Mohan" qualification, including notice under s. 657.3 of the Code, before a certified drug expert can give opinion evidence.[1]

254
...
Evaluation
(3.1) If a peace officer has reasonable grounds to believe that a person is committing, or at any time within the preceding three hours has committed, an offence under paragraph 253(1)(a) as a result of the consumption of a drug or of a combination of alcohol and a drug, the peace officer may, by demand made as soon as practicable, require the person to submit, as soon as practicable, to an evaluation conducted by an evaluating officer to determine whether the person’s ability to operate a motor vehicle, a vessel, an aircraft or railway equipment is impaired by a drug or by a combination of alcohol and a drug, and to accompany the peace officer for that purpose.


  1. R v Parada, 2016 SKCA 102 (CanLII)
    R v Bingley, 2017 SCC 17 (CaLII)

Blood or Urine Sample

Either a blood or urine sample will be taken after the Drug Assessment. The purpose of the sample is largely confirmatory of the independent conclusion of the DRE on whether there is impairment.

Section 254(3.4) of the Code authorizes the taking of a blood sample:

Samples of bodily substances
(3.4) If, on completion of the evaluation, the evaluating officer has reasonable grounds to believe, based on the evaluation, that the person’s ability to operate a motor vehicle, a vessel, an aircraft or railway equipment is impaired by a drug or by a combination of alcohol and a drug, the evaluating officer may, by demand made as soon as practicable, require the person to provide, as soon as practicable,

(a) a sample of either oral fluid or urine that, in the evaluating officer’s opinion, will enable a proper analysis to be made to determine whether the person has a drug in their body; or
(b) samples of blood that, in the opinion of the qualified medical practitioner or qualified technician taking the samples, will enable a proper analysis to be made to determine whether the person has a drug in their body.

Condition
(4) Samples of blood may be taken from a person under subsection (3) or (3.4) only by or under the direction of a qualified medical practitioner who is satisfied that taking the samples would not endanger the person’s life or health.
...
R.S., 1985, c. C-46, s. 254; R.S., 1985, c. 27 (1st Supp.), s. 36, c. 1 (4th Supp.), ss. 14, 18(F), c. 32 (4th Supp.), s. 60; 1999, c. 32, s. 2(Preamble); 2008, c. 6, s. 19.


CCC

Procedure

There is division of opinion of whether an evaluating officer (DRE) requires that the officer be qualified as an expert entitled to give opinion evidence.[1]

  1. R v Cripps, 2014 ONCJ 189 (CanLII) - court says no expert evidence necessary
    c.f. R v McCarthy, 2014 ONCJ 75 (CanLII) - court requires qualification for expert evidence

Case Digests