TORONTO CRIMINAL and DUI LAWYERS
1. What is operation while impaired by a drug?
Operation while impaired by a drug is defined as operating a conveyance while the person’s ability to operate the conveyance is impaired to any degree by a drug.¹
¹“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 320.14(1)(a).
2. What is a “Conveyance” in this Context?
A conveyance is defined as a motor vehicle, a vessel, an aircraft, or railway equipment.²
²“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.htmll at s 320.11.
3. What is a “Motor Vehicle” in this Context?
A motor vehicle is defined as a vehicle that is drawn, propelled or driven by any means other than muscular power, but does not include railway equipment.³
³“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 2, “Criminal Code, RSC 1985, c C-46” (5 June 2026)
4. What is “Operation” in this Context?
To operate is defined as in respect of a motor vehicle, to drive the motor vehicle or to have care or control of the motor vehicle;⁴ in respect of a vessel or aircraft, to navigate the vessel or aircraft, to assist in the vessel’s or aircraft’s navigation or to have care or control of the vessel or aircraft;⁵ and in respect of railway equipment, to participate in the direct control of the railway equipment’s motion, or to have care or control of the railway equipment as a member of the equipment’s crew, as a person who acts in lieu of a member of the equipment’s crew by remote control, or otherwise.⁶
⁴“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 320.11.
⁵“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 320.11.
⁶“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 320.11.
5. Does the fact that an accused has a blood drug concentration sufficient to make the accused’s operation of a conveyance unlawful always prove that the accused’s operation of the conveyance is impaired by a drug?
Although it is an offence for an accused to have a blood drug concentration equal to or exceeding the blood drug concentration for the drug that is prescribed by regulation within two hours after ceasing to operate a conveyance,⁷ the fact that an accused has a blood drug concentration sufficient to make the accused’s operation of a conveyance unlawful does not always prove that the accused’s operation of the conveyance is impaired by a drug.⁸
⁷“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.14(1), 320.14(1)(c).
⁸See, e.g., “R. v. Senthilgumar, 2025 ONCJ 202 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj202/2025oncj202.html at paras 1-2, 7-12, 16-17, 20, 28, 33, 39-40.
6. What are the Essential Elements of "Operation While Impaired by a Drug"?
The essential elements of "Operation While Impaired by a Drug" have been defined as
1. That the accused operated a conveyance⁹
2. While the accused’s ability to operate the conveyance was impaired to any degree by a drug.¹⁰
⁹“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 320.14(1)(a).
¹⁰“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 320.14(1)(a).
7. What is the Actus Reus of "Operation While Impaired by a Drug"?
The actus reus of operation of a conveyance while impaired by a drug is the act of operating a conveyance when the voluntary consumption of a drug has impaired the accused’s ability to operate the conveyance.¹¹
¹¹Cf, “R. v. Castelblanco Velasco, 2019 ONCJ 84 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2019/2019oncj84/2019oncj84.html at para 115.
8. What is the Mens Rea of "Operation While Impaired by a Drug"?
The mens rea of operation of a conveyance while impaired by a drug is the intent to operate a conveyance after voluntarily consuming a drug¹² while having knowledge of, or reckless indifference to, the fact that the drug could impair the ability to operate a conveyance.¹³
¹²Cf, “R. v. Castelblanco Velasco, 2019 ONCJ 84 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2019/2019oncj84/2019oncj84.html at para 115.
¹³“R. v. Norris, 2023 ONSC 4622 (CanLII)” https://www.canlii.org/en/on/onsc/doc/2023/2023onsc4622/2023onsc4622.html at para 115, read in context with “Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.14(1), 320.14(1)(a).
9. How is impairment by a drug defined in this Context?
Before convicting an accused of operation while impaired by a drug, the trier of fact must be satisfied that the accused's ability to operate a conveyance was impaired by a drug, and if the evidence establishes any degree of impairment ranging from slight to great, the offence of impaired operation has been made out.¹⁴ If the ability to operate a conveyance is impaired even slightly by a drug, it is not necessary that the degree of that impairment be marked.¹⁵ But the Court must not fail to recognize the subtle but crucial distinction between slight impairment generally and slight impairment of a person’s ability to operate a conveyance.¹⁶ It is a misinterpretation of the jurisprudence to read the jurisprudence as requiring only proof of an accused’s slight degree of impairment by a drug rather than a slight degree of impairment of an accused’s ability to operate a conveyance as a result of the consumption of a drug.¹⁷
Slight impairment of the ability to operate a conveyance relates to a reduced ability, in some measure, to perform a complex motor function and can affect perception or field of vision, reaction or response time, judgment, or regard for the rules of the road.¹⁸
The impairment of an accused’s ability to operate a conveyance is generally understood as meaning the alteration of one’s judgment and the decrease in one’s physical abilities.¹⁹
Before a trier of fact can make a finding of guilt about a charge of operation while impaired by a drug, the trier of fact must be satisfied beyond a reasonable doubt that the accused’s ability to operate a conveyance was impaired to some degree by a drug.²⁰
The Crown is not required to prove which drug caused the impairment or that the drug was the impairment’s sole cause in order to convict the accused as long as the Crown can establish beyond a reasonable doubt that the accused’s impairment was caused in part by a drug beyond a de minimis influence.²¹
Whether an accused was impaired while operating a conveyance is essentially a question of fact which a trier of fact must determine based upon the evidence.²²
¹⁴Cf, “R. v. Stellato, 1993 CanLII 3375 (ON CA)” https://www.canlii.org/en/on/onca/doc/1993/1993canlii3375/1993canlii3375.html, “R. v. Stellato, [1994] 2 S.C.R. 478” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/1146/index.do, “R. v. Stellato, 1994 CanLII 94 (SCC), [1994] 2 SCR 478” https://www.canlii.org/en/ca/scc/doc/1994/1994canlii94/1994canlii94.html, read in context with “Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.11, 320.14(1)(a).
¹⁵Cf, “R. v. Andrews, 1996 ABCA 23 (CanLII)” https://www.canlii.org/en/ab/abca/doc/1996/1996abca23/1996abca23.html at para 18, read in context with “Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.11, 320.14(1)(a).
¹⁶Cf, “R. v. Andrews, 1996 ABCA 23 (CanLII)” https://www.canlii.org/en/ab/abca/doc/1996/1996abca23/1996abca23.html at para 19, read in context with “Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.11, 320.14(1)(a).
¹⁷Cf, “R. v. Thompson, 2012 ONCJ 377 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2012/2012oncj377/2012oncj377.html at para 13, read in context with “Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.11, 320.14(1)(a).
¹⁸Cf, “R. v. Dupuis, 2020 ONCJ 80 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2020/2020oncj80/2020oncj80.html at para 20, read in context with “Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.11, 320.14(1)(a).
¹⁹Cf, “R. v. Castelblanco Velasco, 2019 ONCJ 84 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2019/2019oncj84/2019oncj84.html at para 117.
²⁰Cf, “R. v. Castelblanco Velasco, 2019 ONCJ 84 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2019/2019oncj84/2019oncj84.html at para 118.
²¹“R. v. Greenwood, 2010 ONSC 912 (CanLII)” https://www.canlii.org/en/on/onsc/doc/2010/2010onsc912/2010onsc912.html at paras 1-2, 35-36.
²²Cf, “R. v. Ramroop, 2021 ONCA 642” https://coadecisions.ontariocourts.ca/coa/coa/en/item/19954/index.do at para 11.
10. What is acceptable proof that an accused is impaired in ability to operate a conveyance by a drug?
There is no special test for determining impairment of the ability to operate a conveyance by a drug.²³
Courts have considered a number of factors in determining whether an accused’s ability to operate a conveyance was impaired as a result of a drug, including lay opinions from witnesses, accidents, speech, appearance of eyes and face, gross and fine motor skills, mental ability and emotional state, alternative explanations for indicia of impairment, and admissions of consumption of drugs by the accused.²⁴
In any proceedings for impaired operation, evidence that the accused, without reasonable excuse, failed or refused to comply with a demand to provide a sample or to submit to testing for the purpose of providing evidence that the accused’s operation of a conveyance was unlawful due to intoxicants is admissible, and the Court may draw an inference adverse to the accused from that evidence.²⁵ Whether the Court draws this inference should depend upon the circumstances because there may be times when the refusal occurs for reasons which, although not legally valid, fall short of satisfying the Court that the refusal arose from consciousness of guilt.²⁶
²³Cf, “R. v. Ramroop, 2021 ONCA 642” https://coadecisions.ontariocourts.ca/coa/coa/en/item/19954/index.do at para 11.
²⁴Cf, “R. v. Castelblanco Velasco, 2019 ONCJ 84 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2019/2019oncj84/2019oncj84.html at para 122.
²⁵“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.14(1)(a), 320.27(1), 320.27(1)(a), 320.27(1)(b), 320.27(1)(c), 320.27(2), 320.28(1), 320.28(1)(a), 320.28(1)(a)(i), 320.28(1)(a)(ii), 320.28(1)(b), 320.28(2), 320.28(2)(a), 320.28(2)(b), 320.28(3), 320.28(4), 320.28(4)(a), 320.28(4)(b), 320.31(10).
²⁶“R v McGinnes, 2020 ABPC 269 (CanLII)” https://www.canlii.org/en/ab/abpc/doc/2020/2020abpc269/2020abpc269.html at paras 127-129.
11. How are drugs detected in an accused?
If a peace officer has reasonable grounds to believe that a person has operated a conveyance while the person’s ability to operate the conveyance was impaired to any degree by a drug, the peace officer may, by demand, made as soon as practicable, require the person:
1. to submit, as soon as practicable, to an evaluation conducted by an evaluating officer to determine whether the person’s ability to operate a conveyance is impaired by a drug or by a combination of alcohol and a drug, and to accompany the peace officer for that purpose;²⁷
or
2. o provide, as soon as practicable, the samples of blood that, in the opinion of the qualified medical practitioner or qualified technician taking the samples, are necessary to enable a proper analysis to be made to determine the person’s blood drug concentration.²⁸
If, after completion of the evaluation, the evaluating officer has reasonable grounds to believe that one or more of certain types of drugs is impairing the accused’s ability to operate a conveyance, the evaluating officer shall identify the type or types of drugs in question and may, by demand made as soon as practicable, require the accused to provide, as soon as practicable,
1. a sample of oral fluid or urine that, in the evaluating officer’s opinion, is necessary to enable a proper analysis to be made to ascertain the presence in the person’s body of one or more types of drugs;²⁹ or
2. he samples of blood that, in the opinion of the qualified medical practitioner or qualified technician taking the samples, are necessary to enable a proper analysis to be made to ascertain the presence in the person’s body of one or more types of drugs or to determine the person’s blood drug concentration for one or more of those types of drugs.³⁰
The types of drugs are a depressant;³¹ an inhalant;³² a dissociative anaesthetic;³³ cannabis;³⁴ a stimulant;³⁵ a hallucinogen;³⁶ or a narcotic analgesic.³⁷
²⁷“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.28(2), 320.28(2)(a).
²⁸“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.28(2), 320.28(2)(b).
²⁹“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.28(4), 320.28(4)(a).
³⁰“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.28(4), 320.28(4)(b).
³¹“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.28(4), 320.28(4)(a), 320.28(4)(b), 320.28(5), 320.28(5)(a).
³²“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.28(4), 320.28(4)(a), 320.28(4)(b), 320.28(5), 320.28(5)(b).
³³“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.28(4), 320.28(4)(a), 320.28(4)(b), 320.28(5), 320.28(5)(c).
³⁴“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.28(4), 320.28(4)(a), 320.28(4)(b), 320.28(5), 320.28(5)(d).
³⁵“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.28(4), 320.28(4)(a), 320.28(4)(b), 320.28(5), 320.28(5)(e).
³⁶“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.28(4), 320.28(4)(a), 320.28(4)(b), 320.28(5), 320.28(5)(f).
³⁷“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.28(4), 320.28(4)(a), 320.28(4)(b), 320.28(5), 320.28(5)(g).
12. What is an evaluating officer?
An evaluating officer is a peace officer who has the qualifications prescribed by regulation that are required in order to act as an evaluating officer.³⁸ An evaluating officer must be a certified drug recognition expert [“DRE”] accredited by the International Association of Chiefs of Police.³⁹
³⁸ “Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 320.11.
³⁹“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at s 1.
13. What are “reasonable grounds to believe”?
The standard of reasonable grounds to believe is a standard of credibly-based probability, not the equivalent of a prima facie case, balance of probabilities, or any other numerical formula.⁴⁰ The standard of reasonable grounds to believe only requires a credibly-based probability.⁴¹ The standard of reasonable grounds to believe is a practical, non-technical standard based on factual and practical considerations of everyday life on which reasonable and prudent people act.⁴² The standard of reasonable grounds to believe defies precise definition or quantification into percentages and is neither a scientific nor a metaphysical exercise.⁴³ The standard of reasonable grounds to believe requires a judge to consider whether there is an objective basis which is based upon compelling and credible information.⁴⁴ The standard of suspecting on reasonable grounds is lower than the standard of reasonable grounds to believe.⁴⁵
⁴⁰“R. v. Hayatibahar, 2026 ONCA 507” https://coadecisions.ontariocourts.ca/coa/coa/en/item/24338/index.do at paras 57-58.
⁴¹“R. v. McNeill, 2020 ONCA 313” https://coadecisions.ontariocourts.ca/coa/coa/en/item/18763/index.do at para 32.
⁴²Cf, “R. v. Hayatibahar, 2026 ONCA 507” https://coadecisions.ontariocourts.ca/coa/coa/en/item/24338/index.do at paras 57-58.
⁴³“R. v. Hayatibahar, 2026 ONCA 507” https://coadecisions.ontariocourts.ca/coa/coa/en/item/24338/index.do at paras 57-58.
⁴⁴“Charkaoui v. Canada (Citizenship and Immigration), [2007] 1 S.C.R. 350, 2007 SCC 9” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/2345/index.do at para 39.
⁴⁵“R. v. Poirier, 2016 ONCA 582” https://coadecisions.ontariocourts.ca/coa/coa/en/item/15004/index.do at para 45.
14. What is a way to acquire reasonable grounds to believe that an accused’s ability to operate a conveyance was impaired to any degree by a drug?
If a peace officer has reasonable grounds to suspect that an accused has a drug in the body and that the accused has, within the preceding three hours, operated a conveyance, the peace officer may, by demand, require the person to immediately perform the physical coordination tests prescribed by regulation and to accompany the peace officer for that purpose.⁴⁶ These physical coordination tests, which are known as a Standard Field Sobriety Test, are a way to acquire reasonable grounds to believe that an accused’s ability to operate a conveyance was impaired to any degree by a drug.⁴⁷
⁴⁶“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.27(1), 320.27(1)(a).
⁴⁷Cf, “R. v. Cosentino, 2025 ONCJ 616 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj616/2025oncj616.html at paras 48-52.
15. What are reasonable grounds to suspect?
Although reasonable grounds to suspect and reasonable and probable grounds to believe both must be grounded in objective facts, reasonable grounds to suspect are a lower standard which engages the reasonable possibility rather than probability of crime.⁴⁸
A police officer’s observations of the accused’s driving a motor vehicle, the presence of marijuana in the motor vehicle, the accused’s prescription to use marijuana, and a police officer’s observation of the appellant’s manner of speech are sufficient to meet the required reasonable grounds to suspect justifying subjecting the accused to physical coordination tests.⁴⁹
⁴⁸“R. v. Chehil, 2013 SCC 49, [2013] 3 S.C.R. 220” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/13264/index.do at para 27.
⁴⁹“R. v. Pera, 2023 ONCA 160” https://coadecisions.ontariocourts.ca/coa/coa/en/item/21281/index.do at paras 6, 30-31, read in context with “R. v. Cosentino, 2025 ONCJ 616 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj616/2025oncj616.html at paras 50-51.
16. Who can administer the physical coordination tests?
Although jurisprudence says that only a Standard Field Sobriety Test officer can administer the physical coordination tests,⁵⁰ I have found no statutory or regulatory basis for this limitation. The only limitation imposed by the Criminal Code is that only a peace officer can demand physical coordination tests.⁵¹
⁵⁰“R. v. Cosentino, 2025 ONCJ 616 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj616/2025oncj616.html at paras 50-51.
⁵¹“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.27(1), 320.27(1)(a).
17. What is a peace officer?
A peace officer includes a mayor, warden, reeve, sheriff, deputy sheriff, sheriff’s officer and justice of the peace; a member of the Correctional Service of Canada who is designated as a peace officer pursuant to Part I of the Corrections and Conditional Release Act, and a warden, deputy warden, instructor, keeper, jailer, guard and any other officer or permanent employee of a prison other than a penitentiary as defined in Part I of the Corrections and Conditional Release Act; a police officer, police constable, bailiff, constable, or other person employed for the preservation and maintenance of the public peace or for the service or execution of civil process, a designated officer as defined in section 2 of the Integrated Cross-border Law Enforcement Operations Act, when participating in an integrated cross-border operation, as defined in section 2 of that Act, or engaging in an activity incidental to such an operation, including travel for the purpose of participating in the operation and appearances in court arising from the operation; an officer within the meaning of the Customs Act, the Excise Act or the Excise Act, 2001, or a person having the powers of such an officer, when performing any duty in the administration of any of those Acts; an officer authorized under subsection 138(1) of the Immigration and Refugee Protection Act; a person designated as a fishery guardian under the Fisheries Act when performing any duties or functions under that Act and a person designated as a fishery officer under the Fisheries Act when performing any duties or functions under that Act or the Coastal Fisheries Protection Act; the pilot in command of an aircraft registered in Canada under regulations made under the Aeronautics Act, or leased without crew and operated by a person who is qualified under regulations made under the Aeronautics Act to be registered as owner of an aircraft registered in Canada under those regulations, while the aircraft is in flight; and officers and non-commissioned members of the Canadian Forces who are appointed for the purposes of section 156 of the National Defence Act, or employed on duties that the Governor in Council, in regulations made under the National Defence Act for the purposes of this paragraph, has prescribed to be of such a kind as to necessitate that the officers and non-commissioned members performing them have the powers of peace officers.⁵²
⁵²“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 2.
18. What are the physical coordination tests?
The physical coordination tests are the horizontal gaze nystagmus test;⁵³ the walk-and-turn test;⁵⁴ and the one-leg stand test.⁵⁵
The horizontal gaze nystagmus test involved first ensuring that a subject’s eyes’ pupils are of equal size and then holding a stimulus such as a pen twelve to fifteen inches from the eyes and moving that stimulus across the plane of each eye in order to test equal tracking of the eye twice with both eyes.⁵⁶
The walk-and-turn test requires a person to walk heel to toe with hands by the side for side nine steps, turn, and then take nine steps back.⁵⁷
The one leg stand test is a divided-attention test in which an accused is required to stand on one leg for thirty seconds with the alternate leg raised in front of the accused six inches off the ground and to count to thirty seconds and only then put the raised foot down.⁵⁸
Peace officers are entitled to rely on an accused’s poor performance on any one of the three physical coordination tests as an indicium of impairment sufficient to make lawful a further demand.⁵⁹
⁵³“R. v. Cosentino, 2025 ONCJ 616 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj616/2025oncj616.html at para 51, read in context with “Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 2, 2(a).
⁵⁴“R. v. Cosentino, 2025 ONCJ 616 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj616/2025oncj616.html at para 51, read in context with “Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 2, 2(b).
⁵⁵“R. v. Cosentino, 2025 ONCJ 616 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj616/2025oncj616.html at para 51, read in context with “Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 2, 2(c).
⁵⁶“R. v. Snelgrove, 2012 BCPC 218 (CanLII)” https://www.canlii.org/en/bc/bcpc/doc/2012/2012bcpc218/2012bcpc218.html at paras 16-17.
⁵⁷“R. v. Jurcevic, 2010 ONCJ 577 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2010/2010oncj577/2010oncj577.html at para 16.
⁵⁸“R. v. Conron, 2012 ONCJ 171 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2012/2012oncj171/2012oncj171.html at para 10, read in context with “R. v. D.A.H., 2016 ONCJ 585 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2016/2016oncj585/2016oncj585.html at para 95.
⁵⁹“R. v. Cosentino, 2025 ONCJ 616 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj616/2025oncj616.html at paras 50-51, read in context with “R. v. Kranz, 2021 ONSC 25 (CanLII)” https://www.canlii.org/en/on/onsc/doc/2021/2021onsc25/2021onsc25.html at para 80.
19. For what purpose can the evidence from the physical coordination tests be used?
The evidence from the physical coordination tests is only admissible to provide grounds to make a demand for the evaluation and not for proof of impairment.⁶⁰
⁶⁰“R. v. Imrie, 2017 ONCJ 383 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2017/2017oncj383/2017oncj383.html at para 363, read in context with “R. v. Cosentino, 2025 ONCJ 616 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj616/2025oncj616.html at paras 48-52.
20. Is it legal to refuse to submit to the physical coordination tests in this Context?
A person who knows that a demand for the physical coordination tests has been made who fails or refuses to comply, without reasonable excuse, with such a demand commits an offence.⁶¹
⁶¹“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.15(1), 320.27(1), 320.27(1)(a).
21. What does the evaluation to determine whether an accused’s ability to operate a conveyance is impaired by a drug involve?
The regulation defines the evaluation to determine whether an accused’s ability to operate a conveyance is impaired by a drug [“evaluation”] as consisting of the following tests:
1. a preliminary examination, which consists of measuring the pulse⁶² and
2. determining that the pupils are the same size and that the eyes track an object equally;⁶³
3. eye examinations, which consist of the horizontal gaze nystagmus test,⁶⁴
4. the vertical gaze nystagmus test,⁶⁵ and
5. the lack-of-convergence test;⁶⁶
6. divided-attention tests, which consist of the Romberg balance test,⁶⁷
7. the walk-and-turn test,⁶⁸
8. the one-leg stand test,⁶⁹ and
9. the finger-to-nose test, which includes the test subject tilting the head back and touching the tip of the subject’s index finger to the tip of their nose in a specified manner while keeping the subject’s eyes closed;⁷⁰
10. an examination, which consists of measuring the blood pressure, temperature and pulse;⁷¹
11. an examination of pupil sizes under light levels of ambient light, near total darkness, and direct light⁷² and
12. an examination of the nasal and oral cavities;⁷³
13. an examination, which consists of checking the muscle tone and pulse;⁷⁴ and
14. a visual examination of the arms, neck and, if exposed, the legs for evidence of injection sites.⁷⁵
The regulation establishing this evaluation does not refer to current Criminal Code provisions,⁷⁶ potentially making the evaluation not a lawful way to investigate an accused for impairment by a drug. But the Ontarian case R v Takov⁷⁷ has created controversy about what the evaluation consists of, rather than about whether the evaluation as defined is a lawful way to investigate an accused for impairment by a drug. Takov noted that even though the regulation says that the evaluation has a total of fourteen steps to be performed, the Supreme Court of Canada has referred to Canada’s establishing a twelve-stepped evaluation procedure,⁷⁸ and held that despite the fact that the regulation says that the evaluation has a total of fourteen steps to be performed, the statutory scheme’s overall result is to require a different twelve-stepped evaluation procedure established by the International Association of Chiefs of Police.⁷⁹
An evaluating officer does not have the ability or the expertise to change the standardized process in this twelve-step evaluation.⁸⁰
The twelve steps in this evaluation are as follows:
1. breath alcohol test;
2. interview of arresting officer;
3. preliminary examination and first pulse;
4. eye examinations;
5. divided attention tests (Modified Romberg Balance test, walk and turn test, one leg stand test, finger to nose test);
6. vital signs and second pulse;
7. dark room examinations;
8. check for muscle tone;
9. check for injection sites and third pulse;
10. interrogation, statements, and other observations;
11. opinion of evaluator;
12. toxicological examination.⁸¹
When the police officer who arrested the accused also performs the twelve-step evaluation, the police officer skips this step because there is no need to gather information from the arresting police officer.⁸²
The preliminary examination consists of a series of questions dealing with possible injuries or medical problems, observations of the person’s face, speech, and breath, and an initial examination of the person’s eyes for pupil size, resting nystagmus (involuntary eye movement), and whether the eyes track together.⁸³
The eye examinations consist of a testing for horizontal gaze nystagmus, vertical gaze nystagmus, and lack of convergence.⁸⁴ The lack of convergence test determines if a person’s eyes are able to converge as the person attempts to focus on a stimulus as it is pushed slowly toward the bridge of the person’s nose.⁸⁵
A Modified Romberg Balance test requires a person to estimate thirty seconds while standing with feet together, head back, and eyes closed.⁸⁶ The walk-and-turn test requires a person to walk heel to toe with hands by the side for side nine steps, turn, and then take nine steps back.⁸⁷
The finger to nose test requires a person to keep heels and toes together, arms by the side, head tilted back, and eyes closed and then touch the tip of the person’s index finger to the tip of the person’s nose which whichever hand is ordered on command.⁸⁸
The one leg stand test is a divided-attention test in which an accused is required to stand on one leg for thirty seconds with the alternate leg raised in front of the accused six inches off the ground and to count to thirty seconds and only then put the raised foot down.⁸⁹
⁶²“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(a).
⁶³“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(a).
⁶⁴“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(b), 3(b)(i).
⁶⁵“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(b), 3(b)(ii).
⁶⁶“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(b), 3(b)(iii).
⁶⁷“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(c), 3(c)(i).
⁶⁸“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(c), 3(c)(ii).
⁶⁹“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(c), 3(c)(iii).
⁷⁰“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.htmll at ss 3, 3(c), 3(c)(iv).
⁷¹“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(d).
⁷²“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(e).
⁷³“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(e).
⁷⁴“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(f).
⁷⁵“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at ss 3, 3(g).
⁷⁶“Evaluation of Impaired Operation (Drugs and Alcohol) Regulations (SOR/2008-196)” (14 June 2026) https://laws-lois.justice.gc.ca/eng/regulations/SOR-2008-196/FullText.html at s 3.
⁷⁷“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html
⁷⁸“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at paras 63-65.
⁷⁹“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at paras 42-43, 51-54, 65, 69-71.
⁸⁰“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at para 144.
⁸¹“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at Appendix A.
⁸²“R. v. Biagi, 2014 ONCJ 153 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2014/2014oncj153/2014oncj153.html at paras 50, 53.
⁸³“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at paras 115-116.
⁸⁴“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at paras 128, 132, 137, Appendix A.
⁸⁵“R. v. Wilson, 2026 ONCJ 211 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2026/2026oncj211/2026oncj211.html at paras 152-153.
⁸⁶“R. v. Kler, 2016 ONCJ 630 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2016/2016oncj630/2016oncj630.html at para 24.
⁸⁷“R. v. Jurcevic, 2010 ONCJ 577 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2010/2010oncj577/2010oncj577.html at para 16.
⁸⁸“R. v. Jurcevic, 2010 ONCJ 577 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2010/2010oncj577/2010oncj577.html at para 16, as supplemented by “R. v. Biagi, 2014 ONCJ 153 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2014/2014oncj153/2014oncj153.html at para 64.
⁸⁹“R. v. Conron, 2012 ONCJ 171 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2012/2012oncj171/2012oncj171.html at para 10, understood in context with “R. v. D.A.H., 2016 ONCJ 585 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2016/2016oncj585/2016oncj585.html at para 95.
22. What presumptions apply to this evaluation?
An evaluating officer’s opinion relating to the impairment by a type of drug that the evaluating officer identified of a person’s ability to operate a conveyance is admissible in evidence without qualifying the evaluating officer as an expert.⁹⁰
It is recognized and declared that an evaluation conducted by an evaluating officer is a reliable method of determining whether a person’s ability to operate a conveyance is impaired by a drug.⁹¹
If the analysis of a sample collected from a person due to an evaluating officer’s reasonable grounds to believe that at least one type of drug is impairing a person’s ability to operate a conveyance demonstrates that the person has a drug in the body that is of a type that the evaluating officer identified as impairing the person’s ability to operate a conveyance, then that drug is presumed, in the absence of evidence to the contrary, to be the drug that was present in the person’s body at the time when the person operated the conveyance and, on proof of the person’s impairment, to have been the cause of the impairment.⁹²
⁹⁰“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 320.31(5).
⁹¹“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.12, 320.12(d).
⁹²“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.28(4), 320.31(6).
23. What limitations apply to these presumptions?
The declaration that an evaluation conducted by an evaluating officer is a reliable method of determining whether a person’s ability to operate a conveyance is impaired by a drug is not a requirement that a Court must accept an evaluating officer’s conclusion about impairment.⁹³
The focus of any challenge must be upon the evaluating officer’s administration of the evaluation’s twelve steps rather than upon the reliability of the steps underlying the evaluation.⁹⁴
Limitations, such as the absence of a standardized approach to weighing the various tests in reaching a determination, may affect the evaluating officer’s opinion evidence’s probative value.⁹⁵ If the evaluating officer’s evidence’s probative value is so diminished that the benefits in admitting the evidence are outweighed by the potential harm to the trial process, a trial judge retains the discretion to exclude that evidence.⁹⁶ An evaluating officer may be unable to explain how the evaluating officer made the determination based upon applying the twelve-step evaluation.⁹⁷
An evaluating officer is only an expert in the administration of the twelve-stepped evaluation procedure established by the International Association of Chiefs of Police,⁹⁸ not an expert in recognizing an accused’s indicia of drugs,⁹⁹ An evaluating officer cannot give an opinion that a given trait is an indicium of impairment by a drug when that trait is not listed as an indicium in the twelve-step evaluation.¹⁰⁰
Deviations by the evaluating officer from the twelve-step evaluation can affect the evaluating officer’s evidence’s reliability and in turn affect the weight given to the evaluating officer’s testimony when considering whether the Crown has proven that the evaluating officer identified a type of drug as impairing an accused’s ability to operate a conveyance.¹⁰¹
An evaluating officer who skips even one of the twelve steps in the twelve-step evaluation does not complete an evaluation and therefore the evaluating officer’s opinion about what drug the accused was impaired by becomes inadmissible opinion evidence.¹⁰²
The presumption that a drug is the drug that was present in the person’s body at the time when the person operated the conveyance and, on proof of the person’s impairment, to have been the cause of the impairment¹⁰³ is not a presumption of guilt.¹⁰⁴
The presumption that a drug is the drug that was present in the person’s body at the time when the person operated the conveyance and, on proof of the person’s impairment, to have been the cause of the impairment¹⁰⁵ has the following obstacles preventing an accused from being convicted when an evaluating officer and a bodily sample’s analysis agree that the accused had a drug in the body.
Firstly, the Court can avoid concluding, despite this evidence and the presumptions, that the accused’s ability to operate the conveyance was impaired.¹⁰⁶
Secondly, evidence to the contrary, such as evidence that creates reasonable doubt about the validity of the presumption, can be adduced in order to rebut this presumption.¹⁰⁷ One form of evidence to the contrary is evidence from which the trier of fact can conclude that the accused’s apparent impairment had a more benign explanation than a drug.¹⁰⁸
Thirdly, the Court can conclude that because the evaluating officer performed the twelve-step evaluation so poorly, the evaluating officer’s opinion should not be accepted as true, meaning that the presumption does not apply.¹⁰⁹
⁹³“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at paras 31-33.
⁹⁴Cf, “R. v. Bingley, 2017 SCC 12, [2017] 1 S.C.R. 170” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/16417/index.do at para 30.
⁹⁵Cf, “R. v. Bingley, 2017 SCC 12, [2017] 1 S.C.R. 170” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/16417/index.do at para 30.
⁹⁶Cf, “R. v. Bingley, 2017 SCC 12, [2017] 1 S.C.R. 170” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/16417/index.do at para 30, “R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at para 341.
⁹⁷Cf, “R. v. Bingley, 2017 SCC 12, [2017] 1 S.C.R. 170” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/16417/index.do at para 30.
⁹⁸“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at paras 61, 71, 215, 285.
⁹⁹“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at para 285.
¹⁰⁰“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at paras 214-217.
¹⁰¹“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at paras 310-311, 313, 326, read in combination with “Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 320.31(6).
¹⁰²“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at paras 75, 78-79, 82-86.
¹⁰³Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 320.31(6).
¹⁰⁴See, e.g., “R. v. Amarelo-Gemus, 2019 ONSC 2675 (CanLII)” https://www.canlii.org/en/on/onsc/doc/2019/2019onsc2675/2019onsc2675.html at paras 57-58.
¹⁰⁵“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 320.31(6).
¹⁰⁶See, e.g., “R. v. Culp, 2025 ONCJ 698 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj698/2025oncj698.html at paras 12-13.
¹⁰⁷See, e.g., “R. v. Culp, 2025 ONCJ 698 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj698/2025oncj698.html at paras 12-13.
¹⁰⁸See, e.g., “R. v. Allison, 2024 YKTC 11 (CanLII)” https://www.canlii.org/en/yk/yktc/doc/2024/2024yktc11/2024yktc11.html at paras 7-9.
¹⁰⁹“R. v. Takov, 2025 ONCJ 316 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj316/2025oncj316.html at paras 287-293, 313-332.
24. Is an evaluation of lesser probative value for an accused who has medical issues?
When an accused has clear and observable disabilities, the Court can and should consider how and whether the accused’s clear and observable disabilities may impact the twelve-step evaluation’s reliability;¹¹⁰ but without expert evidence to confirm that the accused’s disability nullifies the twelve-step evaluation’s results, the fact that the accused has a medical issue does not mean that the Crown cannot meet its standard of proof through the accused’s performance in the twelve-step evaluation.¹¹¹ However, an accused is not required to present expert evidence about the accused’s disabilities in order for the accused to benefit from doubt about whether the accused’s performance in the twelve-step evaluation was affected by the accused’s clear and observable disabilities.¹¹²
¹¹⁰“R. v. Crossman, 2026 ONCJ 155 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2026/2026oncj155/2026oncj155.html at paras 11, 38.
¹¹¹“R. v. Crossman, 2026 ONCJ 155 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2026/2026oncj155/2026oncj155.html at paras 11, 38-39.
¹¹²“R. v. Crossman, 2026 ONCJ 155 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2026/2026oncj155/2026oncj155.html at paras 11, 38.
25. How can evidence from other witnesses strengthen an accused’s defence when the accused is subjected to an evaluation?
An accused can have the accused’s physician testify about the accused’s poor health as part of the accused’s effort to provide an explanation for the accused’s poor performance in the evaluation aside from being impaired by drugs without having to have the accused’s physician qualified as an expert witness to testify about how or whether the accused’s impairments might have affected the accused’s ability to perform well in the evaluation.¹¹³
An accused can have a witness qualified as an expert witness about narcotics and narcotics’ effects on the human body in order to provide alternative innocent explanations for the signs of impairment observed by witnesses in an accused charged with operation while impaired.¹¹⁴ An accused can have a witness qualified as an expert witness about the clinical effects of drugs on people and the research methods in determining those effects, including any alternate explanations for some of the effects noted by the DRE during an evaluation of an accused who was charged with operation while impaired by a drug.¹¹⁵
¹¹³“R. v. Culp, 2025 ONCJ 698 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj698/2025oncj698.html at paras 1-2, 4, 11, 16, 30, 40, 46.
¹¹⁴See, e.g., “R. v. Tucker, 2016 ONCJ 371 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2016/2016oncj371/2016oncj371.html at paras 1, 20, 127, 129.
¹¹⁵See, e.g., “R. v. Biagi, 2014 ONCJ 153 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2014/2014oncj153/2014oncj153.html at paras 1, 13, 17, 119-120, 124-129, 183-184.
26. What are an expert witness’s limitations?
Where, in any trial or other proceeding, criminal or civil, it is intended by the defence to examine as witnesses professional or other experts entitled according to the law or practice to give opinion evidence, not more than five of such witnesses may be called on either side without the leave of the Court or judge.¹¹⁶
In any proceedings, the evidence of a person as an expert may be given by means of a report accompanied by the affidavit or solemn declaration of the person, setting out, in particular, the qualifications of the person as an expert¹¹⁷ if the Court recognizes that person as an expert¹¹⁸ and the party intending to produce the report in evidence has, before the proceeding, given to the other party a copy of the affidavit or solemn declaration and the report and reasonable notice of the intention to produce it in evidence.¹¹⁹
The Court may require the person who appears to have signed an affidavit or solemn declaration setting out, in particular, the qualifications of the person as an expert to appear before the Court for examination or cross-examination in respect of the issue of proof of any of the statements contained in the affidavit or solemn declaration or report.¹²⁰
For the purpose of promoting the fair, orderly and efficient presentation of the testimony of witnesses, a party who intends to call a person as an expert witness shall, at least thirty days before the commencement of the trial or within any other period fixed by the justice or judge, give notice to the other party or parties of the party’s intention to call a person as an expert witness,¹²¹ accompanied by the name of the proposed witness,¹²² a description of the area of expertise of the proposed witness that is sufficient to permit the other parties to inform themselves about that area of expertise,¹²³ and a statement of the qualifications of the proposed witness as an expert.¹²⁴
Expert witnesses are permitted to provide expert opinion evidence about matters requiring specialized knowledge.¹²⁵ An expert evidence’s purpose is to assist the trier of fact by providing special knowledge that the ordinary person would not know, not to substitute the expert witness for the trier of fact.¹²⁶ Trials should not devolve into trials by expert witnesses.¹²⁷ A contest of expert witnesses can distract rather than assist the trier of fact.¹²⁸
Expert witnesses have a special duty to the Court to provide fair, objective and non-partisan assistance.¹²⁹ A proposed expert witness who is unable or unwilling to comply with this duty to provide fair, objective and non-partisan assistance is not qualified to give expert evidence and should not be permitted to give expert evidence.¹³⁰ Once an expert witness meets this threshold requirement to give fair, objective, and non-partisan opinion evidence, concerns about an expert witness’s independence or impartiality should be considered as part of the overall weighing of the costs and benefits of admitting the expert evidence.¹³¹
The expert witness’s opinion must be impartial in the sense that the expert witness’s opinion reflects an objective assessment of the matter in dispute.¹³² The expert witness’s opinion must be independent in the sense that the expert witness’s opinion is the product of the expert’s independent judgment, uninfluenced by who has retained the expert witness or the outcome of the litigation.¹³³ The expert witness’s opinion must be unbiased in the sense that the expert witness’s opinion does not unfairly favour one party’s position over another.¹³⁴ The key issue is whether the expert witness’s opinion would not change regardless of which party retains the expert witness.¹³⁵
The test for admitting expert evidence has two steps.
Firstly, the expert evidence must be admissible.¹³⁶ Expert evidence is admissible when the expert evidence meets the threshold requirements of admissibility, which are: that the evidence is logically relevant; the evidence is necessary to assist the trier of fact; the evidence is not subject to any other exclusionary rule; the expert witness is properly qualified, which includes the requirement that the expert witness is willing and able to fulfil the expert witness’s duty to the Court to provide evidence that is impartial, independent, and unbiased.¹³⁷ When the opinion is based upon novel or contested science or science used for a novel purpose, the underlying science also must be reliable for that purpose.¹³⁸
Although an expert witness’s independence and impartiality should not be presumed absent challenge, without a challenge, the expert’s attestation or testimony recognizing and accepting the duty to provide evidence that is impartial, independent, and unbiased is generally sufficient to establish that the threshold requirement is met.¹³⁹
Once the expert witness attests or testifies under oath to recognizing and accepting the duty to provide evidence that is impartial, independent, and unbiased, the burden is on the party opposing the expert evidence’s admission to show that there is a realistic concern that the expert witness’s evidence should not be received because the expert witness is unable and/or unwilling to comply with the duty to provide evidence that is impartial, independent, and unbiased.¹⁴⁰ If the opponent to admitting the evidence does so, the burden to establish on a balance of probabilities this aspect of the admissibility threshold remains on the party proposing to call the expert evidence.¹⁴¹ Proof on a balance of probabilities means that the trier of fact must scrutinize the relevant evidence with care in order to determine whether it is more likely than not that an alleged event occurred.¹⁴² If this is not done, those parts of the expert evidence which are tainted by a lack of independence or impartiality should be excluded.¹⁴³
The mere fact that an expert witness is retained, instructed, and paid by one of the sides in the litigation does not automatically undermine the expert witness’s independence, impartiality and freedom from bias.¹⁴⁴
In most cases, an employment relationship between the expert witness and the party calling the expert witness is insufficient to make the expert witness inadmissible.¹⁴⁵
The fact that an expert witness discovers what the expert witness thinks is or may be professional negligence does not, on its own, disqualify the expert witness from offering that opinion as an expert witness.¹⁴⁶ Provided that the initial work is done independently and impartially and the person put forward as an expert witness understands and is able to comply with the duty to provide fair, objective and non-partisan assistance to the Court, the expert witness meets that threshold qualification.¹⁴⁷
An expert witness does not lack the threshold qualification in relation to the duty to give fair, objective and non-partisan evidence merely because the expert witness relies upon the work of other professionals in reaching the expert witness’s opinion.¹⁴⁸
Secondly, the trial judge must determine that the benefits of admitting the expert evidence outweigh the potential risks of admitting the expert evidence, considering such factors as legal relevance, necessity, reliability, and absence of bias.¹⁴⁹ The trial judge must decide whether expert evidence that meets the preconditions to admissibility is sufficiently beneficial to the trial process to warrant expert evidence’s admission despite the potential harm to the trial process that may flow from the expert evidence’s admission.¹⁵⁰
Even after determining that the expert witness meets the minimum threshold of being sufficiently unbiased, the trial judge must still take concerns about the expert witness’s independence and impartiality into account in determining whether the expert witness is permitted to testify in the second step for determining the expert witness’s admissibility.¹⁵¹
When an accused is convicted after a trial in which evidence reveals that the trier of fact applied no scrutiny to expert evidence provided by the Crown and intense scrutiny to countering expert evidence provided by the accused, a new trial is necessary because this uneven scrutiny wrongly shifted the burden of proof onto the accused.¹⁵²
An accused is permitted to have an expert witness testify about a drug’s effects upon the accused.¹⁵³
¹¹⁶“Canada Evidence Act (R.S.C., 1985, c. C-5)” (14 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 7.
¹¹⁷“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 657.3(1).
¹¹⁸Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 657.3(1)(a).
¹¹⁹“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 657.3(1)(b).
¹²⁰“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 657.3(1), 657.3(2).
¹²¹“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 657.3(3), 657.3(3)(a).
¹²²“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 657.3(3)(a)(i).
¹²³“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 657.3(3)(a)(ii).
¹²⁴“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 657.3(3)(a)(iii).
¹²⁵“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 15.
¹²⁶“R. v. J.‑L.J., [2000] 2 S.C.R. 600” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/1815/index.do at para 56.
¹²⁷“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 118.
¹²⁸“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 18.
¹²⁹“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 2.
¹³⁰“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 2.
¹³¹“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 2.
¹³²“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 32.
¹³³“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 32.
¹³⁴“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 32.
¹³⁵“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 32.
¹³⁶“R. v. Abbey, 2017 ONCA 640” https://coadecisions.ontariocourts.ca/coa/coa/en/item/16013/index.do at paras 47-48.
¹³⁷ “R. v. Abbey, 2017 ONCA 640” https://coadecisions.ontariocourts.ca/coa/coa/en/item/16013/index.do at paras 47-48.
¹³⁸“R. v. Abbey, 2017 ONCA 640” https://coadecisions.ontariocourts.ca/coa/coa/en/item/16013/index.do at paras 47-48.
¹³⁹ “White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at paras 2, 32, 46-47.
¹⁴⁰“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at paras 2, 32, 46-48.
¹⁴¹“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at paras 2, 32, 46-48.
¹⁴²“F.H. v. McDougall, [2008] 3 S.C.R. 41, 2008 SCC 53” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/6211/index.do at para 49.
¹⁴³“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 48.
¹⁴⁴“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 32.
¹⁴⁵“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 49.
¹⁴⁶“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 60.
¹⁴⁷“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 60.
¹⁴⁸“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at para 61.
¹⁴⁹“R. v. Abbey, 2017 ONCA 640” https://coadecisions.ontariocourts.ca/coa/coa/en/item/16013/index.do at paras 47-48.
¹⁵⁰“R. v. Abbey, 2017 ONCA 640” https://coadecisions.ontariocourts.ca/coa/coa/en/item/16013/index.do at para 49.
¹⁵¹“White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23, [2015] 2 S.C.R. 182” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/15328/index.do at paras 10, 46-49.
¹⁵²“R. v. Awer, 2017 SCC 2, [2017] 1 S.C.R. 83” https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/16344/index.do at paras 3-8.
¹⁵³See, e.g., “R. v. Bhogal, 2025 ONCA 487” https://coadecisions.ontariocourts.ca/coa/coa/en/item/23416/index.do at paras 30, 47-48, 59.
27. What is a qualified technician in this Context?
A qualified technician means, in respect of blood samples, a person who is, or a person who is a member of a class of persons that is, designated by the Attorney General to take samples of blood.¹⁵⁴
¹⁵⁴“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.11, 320.4, 320.4(b), 320.4(b)(i).
28. What is a qualified medical practitioner in this Context?
A qualified medical practitioner means a person who is qualified under provincial law to practise medicine.¹⁵⁵
¹⁵⁵“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at s 320.11.
29. Do the different types of bodily sample produce equally good evidence?
A drug’s presence in a urine sample demonstrates only prior drug use or exposure and drugs present only in urine in no way impair a person's ability to operate a conveyance, nor do drugs present only in urine prove the drugs’ presence in a person’s blood when the sample was collected.¹⁵⁶
A drug can be detected in a person’s urine sample after the drug’s effects are gone.¹⁵⁷
A blood sample provides better evidence of what, if any, drugs were active in an accused’s body than a urine sample.¹⁵⁸
¹⁵⁶Cf, “R. v. Culp, 2025 ONCJ 698 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj698/2025oncj698.html at para 9.
¹⁵⁷See, e.g., “R. v. Crossman, 2026 ONCJ 155 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2026/2026oncj155/2026oncj155.html at para 26.
¹⁵⁸“R. v. Culp, 2025 ONCJ 698 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2025/2025oncj698/2025oncj698.html at paras 9-10.
30. What happens when an accused is neither subjected to an evaluation nor subjected to testing of bodily fluids in this Context?
The Crown can try to convict an accused of operation while impaired by a drug even when the accused is not subjected to an evaluation or to testing of bodily fluids by adducing evidence that the accused’s behaviour was consistent with being impaired by a drug.¹⁵⁹ But when the Crown is unable to provide any evidence that the accused was associated with drugs and no evidence that the only explanation for the accused’s behaviour is the accused’s use of drugs, the accused must be acquitted of operation while impaired by a drug on the basis that there remains a reasonable doubt about whether the accused was impaired by a drug.¹⁶⁰
¹⁵⁹See, e.g., “R. v. Langfeld, 2017 ONCJ 382 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2017/2017oncj382/2017oncj382.html at paras 1-2, 10, 17-21, 25-27.
¹⁶⁰See, e.g., “R. v. Langfeld, 2017 ONCJ 382 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2017/2017oncj382/2017oncj382.html at paras 1-2, 10, 17-21, 25-27, 31-33, 39-40, 43-45.
31. Is it legal to refuse to submit to an evaluation or to testing of bodily fluids in this Context?
A person who knows that a demand for an evaluation or for testing of bodily fluids has been made who fails or refuses to comply, without reasonable excuse, with such a demand commits an offence.¹⁶¹
¹⁶¹“Criminal Code (R.S.C., 1985, c. C-46)” (5 June 2026) https://laws.justice.gc.ca/eng/acts/C-46/FullText.html at ss 320.15(1), 320.28(2), 320.28(2)(a), 320.28(2)(b), 320.28(4), 320.28(4)(a), 320.28(4)(b).
32. Can an accused be convicted for operation while impaired by a legal drug used for a medicinal reason?
An accused can be convicted for operation while impaired by a legal drug used for a medicinal reason, even when the drug is prescribed to the accused and the accused follows the prescription’s instructions.¹⁶²
¹⁶²See, e.g., “R. v. Ahola, 2025 ONSC 2614 (CanLII)” https://www.canlii.org/en/on/onsc/doc/2025/2025onsc2614/2025onsc2614.html at paras 1-2, 43.
33. How should claims that an accused involuntarily consumed a drug be dealt with?
An accused is presumed to have become intoxicated voluntarily.¹⁶³ Involuntary intoxication occurs when an accused either unknowingly takes a drug or knowingly takes drugs whose effects are unknown to the accused.¹⁶⁴
The defence of involuntary intoxication, although often conflated and/or confused with the defence of automatism, is separate from the defence of automatism.¹⁶⁵
Any degree of intoxication, even if not intoxication causing automatism, can support a defence of involuntary intoxication.¹⁶⁶
Because intoxication’s voluntariness is assumed, absent evidence to the contrary, the accused must raise a reasonable doubt about voluntary consumption before a defence of involuntary intoxication can succeed.¹⁶⁷ Although the presumption of voluntary intoxication is rebuttable, the defence only needs to point to evidence that raises a reasonable doubt about the intoxication’s voluntariness and does not need to prove anything on a balance of probabilities.¹⁶⁸ This means that when the accused raises the defence of involuntary intoxication, the accused has no burden to prove anything, and the burden remains with the Crown to prove beyond a reasonable doubt that the accused’s act was voluntary.¹⁶⁹
When an accused raises the defence of involuntary intoxication to the charge of impaired operation, the accused is, for the defence’s purposes, conceding that the accused’s actions fulfilled the actus reus of the charge of impaired operation but is alleging that the accused lacked the mens rea sufficient to be convicted of impaired operation.¹⁷⁰
If the accused can raise a reasonable doubt about the intoxication’s voluntariness and whether the accused realized impairment before operating a conveyance, then the accused must be acquitted of offences related to operating a conveyance unlawfully due to intoxicants.¹⁷¹
An accused’s recklessness about a substance’s impairing effects on the ability to operate a conveyance is sufficient to establish mens rea for impaired operation.¹⁷² But when an accused is genuinely involuntarily impaired, that very impairment may serve as a legitimate explanation for why the accused, having become impaired, failed to avoid unlawfully operating a conveyance.¹⁷³
¹⁶³See, e.g., “R. v. Rutherford, 2015 ONCJ 275 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2015/2015oncj275/2015oncj275.html at paras 1, 155-170.
¹⁶⁴“R. v. McGrath, 2013 ONCJ 528 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2013/2013oncj528/2013oncj528.html at para 6.
¹⁶⁵“R. v. Hallahan, 2021 ONCJ 156 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2021/2021oncj156/2021oncj156.html at paras 4, 24-28.
¹⁶⁶“R. v. McGrath, 2013 ONCJ 528 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2013/2013oncj528/2013oncj528.html at para 8.
¹⁶⁷“R. v. McGrath, 2013 ONCJ 528 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2013/2013oncj528/2013oncj528.html at para 12.
¹⁶⁸“R. v. Magdallah, 2024 ONSC 3660 (CanLII)” https://www.canlii.org/en/on/onsc/doc/2024/2024onsc3660/2024onsc3660.html at paras 1, 11.
¹⁶⁹“R. v. Hallahan, 2021 ONCJ 156 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2021/2021oncj156/2021oncj156.html at para 23.
¹⁷⁰“R. v. White, 2022 ONCJ 600 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2022/2022oncj600/2022oncj600.html at paras 1-2, 5, 27.
¹⁷¹“R. v. McGrath, 2013 ONCJ 528 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2013/2013oncj528/2013oncj528.html at para 13.
¹⁷²“R. v. White, 2022 ONCJ 600 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2022/2022oncj600/2022oncj600.html at para 37.
¹⁷³“R. v. Domb, 2011 ONCJ 756 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2011/2011oncj756/2011oncj756.html at paras 1-6, 86, 88.
34. What is useful to know about a defence of involuntary intoxication involving medicine?
Those who take medications must be vigilant in recognizing when their prescribed medications are impairing them, and cannot put other people at risk just because they believe that since their doctor prescribed the medications and they have been taking the medications for a long time and have felt fine before, they can continue to operate conveyances and ignore the symptoms when their medications are impairing them on a particular day.¹⁷⁴
A trier of fact is permitted to take into account an accused’s actual and reasonably expected expertise about medicine when deciding whether the accused’s allegation of involuntary intoxication arising from medicine succeeds as a defence.¹⁷⁵
A trier of fact does not need to accept completely an accused’s evidence that the accused was not aware that the accused’s taking certain combination of medicines could cause impairment in order for the defence of involuntary intoxication to succeed when all of the evidence leaves the accused with a reasonable doubt about whether the accused was aware of or reckless to the fact that taking the accused’s prescribed medications alone or in combination with another medicine could cause impairment.¹⁷⁶
An accused who takes an impairing type of medicine while thinking that the accused is taking a non-impairing medicine in circumstances revealing that the accused’s mistake was reasonable can benefit from the defence of involuntary intoxication.¹⁷⁷
¹⁷⁴“R. v. Imrie, 2017 ONCJ 383 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2017/2017oncj383/2017oncj383.html at paras 1, 361-362, 369-370.
¹⁷⁵Cf, “R. v. Nash, 2012 ONSC 4604 (CanLII)” https://www.canlii.org/en/on/onsc/doc/2012/2012onsc4604/2012onsc4604.html at paras 72, 75, 89-90.
¹⁷⁶See, e.g., “R v. Blais, 2018 ONCJ 784 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2018/2018oncj784/2018oncj784.html at paras 1-3, 44-54.
¹⁷⁷“R. v. Rusnov, 2009 ONCJ 564 (CanLII)” https://www.canlii.org/en/on/oncj/doc/2009/2009oncj564/2009oncj564.html at paras 1-2, 35-36, 42-44, 51, 84-87.