The Defence Toolkit – November 1, 2025: The Good Samaritan



Experts | Fresh Evidence | Good Samaritan



Posted On 1 November 2025

This week’s top three summaries: R v Wilson, 2025 SCC 32: #GoodSamaritan, R v Ukuqtunnuaq, 2025 NUCA 8: #fresh evidence, R v Liu, 2025 SKCA 98: #expert evidence

R. v. Wilson, 2025 SCC 32

[October 24, 2025] The Good Samaritan Exception to Drug Possession [Majority Reasons by Karakatsanis J. with Wagner C.J. and Martin, Kasirer, O’Bonsawin and Moreau JJ. concurring and Jamal, Cote, and Rowe dissenting JJ. dissenting]

AUTHOR’S NOTE: Immunity from Arrest under the Good Samaritan Drug Overdose Act

The Good Samaritan Drug Overdose Act amended the Controlled Drugs and Substances Act (CDSA) to provide immunity from being charged or convicted for simple possession when a person seeks emergency assistance or remains at the scene of an overdose. The legislative purpose is straightforward and compassionate: saving lives takes precedence over drug possession enforcement.

In this case, the Crown argued that the statutory immunity applied only to being “charged or convicted”, not to being arrested. The Supreme Court of Canada — affirming the Saskatchewan Court of Appeal — rejected that interpretation. The majority held that arrest powers cannot be used to arrest individuals for offences that cannot lawfully result in a charge or conviction. To hold otherwise would defeat the very object of the Act.

Because Mr. Wilson was immune under s. 4.1(2) CDSA when arrested for possession, the police lacked lawful authority to arrest him. All evidence obtained as a result of that unlawful arrest was excluded, and an acquittal on all charges was entered.

Takeaway:
The Good Samaritan Drug Overdose Act provides true immunity, not merely a defence to prosecution. Police cannot lawfully arrest individuals for possession offences when the Act applies — and any evidence derived from such an arrest is subject to exclusion.

I. Overview

[1] In response to a national public health crisis of overdoses and deaths caused by opioids, Parliament has sought to encourage people to call for emergency assistance and remain at the scene of a drug overdose when a life is endangered. In 2017, it enacted the Good Samaritan Drug Overdose Act, S.C. 2017, c. 4 (GSDOA), which added s. 4.1 to the Controlled Drugs and Substances Act, S.C. 1996, c. 19 (CDSA ). Section 4.1(2) provides immunity from being “charged or convicted” for possession of a controlled substance to those good Samaritans1 who call for help or remain at the scene of a drug overdose where evidence of that offence is discovered at the scene. This appeal is about the scope of the immunity offered by the provision — in immunizing individuals from being “charged or convicted”, did Parliament also intend to provide an immunity from arrest?

[2] Paul Eric Wilson was one of four people who remained at the scene of an overdose after 9-1-1 was called. Police arriving at the scene arrested them for the offence of possession of a controlled substance. A search incident to those arrests revealed evidence of other offences for which Mr. Wilson was later tried and convicted. Those convictions were overturned by the Court of Appeal, which found that the arrest was unlawful due to the immunity in s. 4.1(2) of the CDSA . Consequently, it concluded that Mr. Wilson’s right to be free from arbitrary detention under s. 9 of the Canadian Charter of Rights and Freedoms had been infringed. Further, the search incident to that arrest breached Mr. Wilson’s right to be secure from unreasonable search or seizure under s. 8 of the Charter. The Court of Appeal excluded the evidence found during that search under s. 24(2) of the Charter and entered acquittals.

[3] The Crown appeals, arguing before this Court that police officers have lawful authority to arrest people for the offence of simple possession, and to search them incidentally to that arrest, even if those people are immune from charge and conviction for that offence because of s. 4.1(2)…

[4] I would dismiss the Crown’s appeal. The immunity from charge and conviction for simple possession explicitly mentioned in s. 4.1(2) of the CDSA includes, by necessary implication, immunity from arrest for that offence. This interpretation best serves the clear purpose of the provision: to save lives.

[5] An arrest is a significant infringement of personal liberty. It can give rise to searches incident to arrest and to the prosecution of other criminal offences based on those searches. An interpretation of s. 4.1(2) which allows arrests for possession, and intrusive searches incident to those arrests, would maintain a strong disincentive to seek emergency assistance in life-threatening overdose situations. Parliament did not intend this result.

[7] Finally, an interpretation of s. 4.1(2) that provides immunity not only from charge and conviction, but also from arrest on that charge, reflects the fact that our law has never permitted arrest purely for the purposes of investigation and tightly circumscribes the power to arrest and the power to search incidentally to arrest…

[8] This interpretation of s. 4.1(2) does not create a threat to public or officer safety. When responding to the scene of a drug overdose, the police still retain all their usual powers to respond to evidence of crimes other than the specific offence for which s. 4.1(2) offers an immunity and to ensure both their own safety and the safety of the public. For example, the police can still seize controlled substances in plain view. They can conduct certain warrantless searches in exigent circumstances or if necessary to protect their own safety and that of the public. The police can still detain individuals if reasonably necessary in all the circumstances, conduct investigative detentions, or arrest them where there are sufficient grounds to do so outside the scope of the immunity. These powers all have their own thresholds and preconditions for use. Parliament did not intend to allow the police to bypass these preconditions by permitting arrests for an offence that cannot be charged.

II. Facts

[11] By the time the first police officer arrived at the scene, Ms. Delorme was already receiving medical attention from emergency medical services. The officer, Constable Heidi Jo Marshall, observed two men — one of them being Mr. Wilson — lying under the truck, seemingly attempting to repair something, and another woman near the truck. She also saw a small bag containing a white substance on the ground near the driver’s side of the truck, smelled marijuana, and noticed signs of drug impairment in the individuals who had not overdosed

[12] As a result, Constable Marshall detained Mr. Wilson and the other two individuals to investigate possession of a controlled substance contrary to s. 4(1) of the CDSA . During that detention, Constable Marshall observed Mr. Wilson handling something in his pocket and saw some white powder on the ground near Mr. Wilson which was not there before. After some questioning, Mr. Wilson produced a small case from his pocket, which contained syringes.

[13] Constable Marshall arrested Mr. Wilson and the other individuals, including Ms. Delorme, for possession of a controlled substance contrary to s. 4(1) of the CDSA . Two other officers who had arrived at the scene then conducted a search incident to those arrests, searching the truck and the individuals’ belongings, during which they discovered drugs and drug paraphernalia. In a backpack located inside the truck, the police also discovered modified handguns, parts for firearms, and ammunition. While Ms. Delorme was being taken to a hospital, the three individuals who had remained at the scene were rearrested for possession for the purpose of trafficking and firearms offences. Once at the station, Mr. Wilson admitted to the police that the backpack was his, along with the ammunition and guns, although he denied owning the drugs, apart from those found on his person.

B. Court of Appeal for Saskatchewan, 2023 SKCA 106, 429 C.C.C. (3d) 454 (Schwann, Leurer and Drennan JJ.A.)

[20] Because there were no explicit findings of fact in the reasons of the trial judge with respect to Mr. Wilson’s first arrest, the Court of Appeal first examined the record to determine the reason for this arrest. It found that Mr. Wilson and his companions were first detained for the purposes of an investigation into possession of a controlled substance contrary to s. 4(1) of the CDSA and were arrested for that offence soon after. The Court of Appeal also found that the police searches which discovered the hidden firearms and evidence of drug trafficking were incidental to that first arrest. The Court of Appeal held that it was “impossible to read the testimony of th[e] officers in any way other than that the search of Mr. Wilson’s backpack was incidental to his arrest for simple possession of a controlled substance” (para. 36). It further stated that while it interpreted the trial judge as having made the same finding of fact, had he found otherwise, that finding would be a palpable and overriding error.

[21] The Court of Appeal concluded that s. 4.1(2) of the CDSA , read in its grammatical and ordinary sense, means that simple possession remains an offence but that Parliament exempts a person from being charged with or convicted of that offence. Thus, while Mr. Wilson may have been found committing a crime, he could not be arrested under s. 495(1)(b) of the Criminal Code for committing that offence…

[22] The Court of Appeal excluded the evidence under s. 24(2) of the Charter, finding that its admission would bring the administration of justice into disrepute. It entered acquittals on all charges.

[25] This appeal thus requires us to answer these questions:

1. Does the immunity from being “charged or convicted” of the offence of possession of a controlled substance in s. 4.1(2) of the CDSA include an immunity from arrest for that charge?

2. Were Mr. Wilson’s ss. 8 and 9 Charter rights violated by his arrest and the search incident to that arrest?

3. If Mr. Wilson’s Charter rights were violated, should the evidence obtained thereby be excluded under s. 24(2) of the Charter?

V. Analysis

A. The Good Samaritan Drug Overdose Act Amendments

[27] In 2017, Parliament amended the CDSA through the GSDOA. That Act added s. 4.1 to the CDSA . Sections 4.1(2) and 4.1(3) as amended state:

(2) No person who seeks emergency medical or law enforcement assistance because that person, or another person, is suffering from a medical emergency is to be charged or convicted of an offence under subsection 4(1) if the evidence in support of that offence was obtained or discovered as a result of that person having sought assistance or having remained at the scene.

(3) The exemption under subsection (2) also applies to any person, including the person suffering from the medical emergency, who is at the scene on the arrival of the emergency medical or law enforcement assistance.

[28] Section 4.1 creates circumscribed immunities for people who seek emergency assistance or remain at the scene of a medical emergency. A “medical emergency” is defined as “a physiological event induced by the introduction of a psychoactive substance into the body of a person that results in a life-threatening situation and in respect of which there are reasonable grounds to believe that the person requires emergency medical or law enforcement assistance” (s. 4.1(1)). Evidence gathered as a result of having sought assistance or remained at the scene of this kind of emergency cannot be used to support a simple possession charge (s. 4.1(2) and (3)) or to support a charge of violating a condition in a pre-trial release or probation order relating to simple possession (s. 4.1(4)). Moreover, conditions of pre-trial release, probation orders, conditional sentences, or parole which relate to simple possession are deemed not to have been violated at all (s. 4.1(5)), removing the possibility of other legal consequences that may be imposed without charge

[29] The GSDOA began as a private member’s bill, introduced by Ron McKinnon. Speaking in the House of Commons, Mr. McKinnon explained the statute’s goals, stating: “Unfortunately, with drug overdoses, many people are afraid to call 911 for fear of getting charged. People die. Saving lives needs to come first” (House of Commons Debates, vol. 148, No. 22, 1st Sess., 42nd Parl., February 22, 2016, at p. 1196). Ultimately, the bill passed with unanimous support in the House of Commons and Senate

B. Immunity From Arrest Under Section 4.1(2) of the CDSA

[33] The Crown argues that notwithstanding the public health purpose of the provision, the scope of the immunity does not include arrest…

[34] It is true that s. 4.1(2) of the CDSA does not explicitly include the word “arrest” and only references immunity from being “charged” and “convicted”. However, the words of a statutory provision can never be interpreted in isolation (see La Presse inc. v. Quebec, 2023 SCC 22, at para. 23). This Court has long recognized that, despite apparent plainness in language, a provision must be interpreted considering its entire purpose and context — the text is not in itself determinative (ATCO Gas and Pipelines Ltd. v. Alberta (Energy and Utilities Board), 2006 SCC 4, [2006] 1 S.C.R. 140, at para. 48; R. v. Alex, 2017 SCC 37, [2017] 1 S.C.R. 967, at paras. 31-33; La Presse, at para. 30). This is why a phrase in a statute cannot be definitively understood by simply examining definitions of each individual word (see Telus Communications Inc. v. Federation of Canadian Municipalities, 2025 SCC 15, at para. 43; see also R. Sullivan, The Construction of Statutes (7th ed. 2022), at § 3.03[3]).

[35] More specifically, legal change, such as a change in the availability of arrest powers, is not always effected through express statutory language. The Crown is wrong to suggest that “[i]n the absence of clear statutory language to the contrary” the power to arrest must necessarily be unaffected (outline of argument, at para. A(5), in condensed book, tab 1). It is “clear legislative intention”, not clear statutory language, that is required to rebut the presumption against substantial legislative change to existing law (R. v. D.L.W., 2016 SCC 22, [2016] 1 S.C.R. 402, at para. 21; see also R. v. Basque, 2023 SCC 18, at para. 49). In Basque, Kasirer J. noted that statutes can displace pre-existing law without express language, “by necessary implication” (para. 42). The question is not, therefore, whether arrest is expressly referenced in the language of the provision, but whether, correctly interpreted, s. 4.1 of the CDSA limits the power to arrest by necessary implication.

[36] A reading of the provision in its entire context, which reflects Parliament’s purpose to save lives along with Parliament’s understanding of the relationship between charge, conviction, and arrest, demonstrates that the words “charged or convicted” were not used in the narrow sense urged by the Crown. To the extent these words have technical legal meanings in some contexts, those meanings are clearly rebutted by other indicators of intent (see, by analogy, Celgene Corp. v. Canada (Attorney General), 2011 SCC 1, [2011] 1 S.C.R. 3). As I shall explain, where evidence of an offence of possession was discovered as a result of a person having sought emergency assistance or having remained at the scene of an overdose, s. 4.1(2), properly interpreted, means this evidence cannot be grounds for a lawful arrest on that possession charge.

(1) Immunity From Arrest Is Necessary To Achieve Parliament’s Life-Saving Purpose

[38] It has been repeatedly recognized by this Court that arrests and searches incident to arrest are an inherently significant infringement of an individual’s personal liberty and autonomy. As this Court held in Fleming v. Ontario, 2019 SCC 45, [2019] 3 S.C.R. 519, “few police actions interfere with an individual’s liberty more than arrest — an action which completely restricts the person’s ability to move about in society free from state coercion” (para. 65).

[39] Searches incident to arrest are also intrinsically intrusive and can proceed in highly invasive fashions, such as strip searches (R. v. Golden, 2001 SCC 83, [2001] 3 S.C.R. 679), searches of cell phones (R. v. Fearon, 2014 SCC 77, [2014] 3 S.C.R. 621), or searches of individuals’ homes, including those areas outside the arrested person’s physical control (R. v. Stairs, 2022 SCC 11, [2022] 1 S.C.R. 169). As seen in this case, those searches can provide the foundation for charges for offences other than simple possession

[41] Given the well-understood consequences of an arrest, an interpretation of s. 4.1(2) of the CDSA which allows for arrest would greatly undermine Parliament’s intent to save lives by promoting resort to emergency services following a drug overdose. It intended to do so by reducing individuals’ fear of legal consequences should they call 9-1-1…

[43] In endorsing the GSDOA, the Parliamentary Secretary to the Minister of Health made several statements which reflect an intention to immunize from arrest. For example, she stated:

I recognize that problematic drug use is a complex issue for which there are no easy answers, but we cannot arrest our way out of this problem. . . .

. . .

. . .rather than arresting those who are suffering from a disease of addiction, an overdose is an important opportunity for first responders to intervene and help direct individuals toward community and social services to obtain treatment for their illness. [Emphasis added.]

(House of Commons Debates, May 4, 2016, at pp. 2898-99; see also House of Commons Debates, October 28, 2016, at p. 6301.)

[44] Together, these statements reflect a clear understanding that the s. 4.1(2) immunity includes immunity from arrest for the charge of simple possession. It is trite law that courts must not place undue weight on the legislative history of an enactment (see R. v. I.M., 2025 SCC 23, at para. 127; R. v. Khill, 2021 SCC 37, [2021] 2 S.C.R. 948, at para. 111; Rizzo, at para. 35). However, legislative history that, viewed as a whole, provides “a full and consistent picture of the thinking behind a provision” can receive “considerable weight” in the interpretative exercise (Sullivan, at § 23.03[4][b]). This is particularly so when, as here, members of all parties evidenced a similar understanding in Hansard (see, e.g., R. v. Morgentaler, [1993] 3 S.C.R. 463, at p. 485; 1704604 Ontario Ltd. v. Pointes Protection Association, 2020 SCC 22, [2020] 2 S.C.R. 587, at para. 13)

[47] By contrast, other than the absence of an explicit reference to the word “arrest”, there is nothing to support the Crown’s contention that Parliament chose to allow the police to arrest the good Samaritans for the offence of possession. Nothing suggests that Parliament intended for the police to be able to arrest people who are immune from charge, either as a tool for the seizure of drugs (not in plain view) or for the investigation of other potential crimes (for which there are no reasonable suspicions or grounds).

(2) The Broader Context of Section 4.1 Is Consistent With Immunity From Arrest

[50] In addition to conferring immunity from charge and conviction for the offence of simple possession, s. 4.1 of the CDSA provides additional immunities regarding the breach of conditions that relate to simple possession. Sections 4.1(4) and 4.1(5) state:

(4) No person who seeks emergency medical or law enforcement assistance because that person, or another person, is suffering from a medical emergency, or who is at the scene on the arrival of the assistance, is to be charged with an offence concerning a violation of any condition of a pretrial release or probation order relating to an offence under subsection 4(1) if the evidence in support of that offence was obtained or discovered as a result of that person having sought assistance or having remained at the scene.

(5) Any condition of a person’s pre-trial release, probation order, conditional sentence or parole relating to an offence under subsection 4(1) that may be violated as a result of the person seeking emergency medical or law enforcement assistance for their, or another person’s, medical emergency, or as a result of having been at the scene on the arrival of the assistance, is deemed not to be violated.

[52] These additional protections reflect Parliament’s clear goal to remove disincentives to seek emergency assistance that could save lives. Section 4.1(5) goes beyond providing immunity for condition violations — it deems the violations not to have occurred. Deeming such conditions not to have been breached is necessary to immunize eligible individuals from the consequences arising from their breach that do not require a criminal charge (see I.F., John Howard Society of Saskatchewan, at para. 22). For example, violating pre-trial release conditions can result in cancellation of the release order (Criminal Code , s. 524). Since those consequences are specific to these condition violations, it is unsurprising that a similar deeming provision was not enacted for the offence of possession.

(3) Parliament Would Not Have Preserved Arrests for Offences Immune From Charge and Conviction as a Pretext for Investigating Other Offences

[57] …In enacting s. 4.1(2), Parliament did not intend to allow the police to arrest individuals for the offence of simple possession, despite those individuals being immune from charge and conviction, to further other law enforcement goals. Parliament is presumed to know the law, and our law has long prohibited a warrantless arrest under s. 495 of the Criminal Code for purely investigative purposes. Accepting the Crown’s position would expand the s. 495 power to arrest contrary to the jurisprudence of this Court. It would permit the exercise of the power of arrest in a way that is disconnected from the purposes for which that power was granted to the police.[Emphasis by PJM]

[58] Arrest is not a power to be exercised lightly. It is a significant deprivation of personal liberty. As this Court stated in Kosoian v. Société de transport de Montréal, 2019 SCC 59, [2019] 4 S.C.R. 335, “[i]n a free and democratic society, no one should accept — or expect to be subjected to — unjustified state intrusions. Interference with freedom of movement, just like invasion of privacy, must not be trivialized” (para. 139; see also Fleming, at paras. 65 and 91).[Emphasis by PJM]

[59] An arrest is also a very specific exercise of police powers, which in turn gives rise to other police powers, most notably search incident to arrest. In this sense, arrest is distinct from other powers which may be exercised by the police, such as investigative detention (see R. v. Mann, 2004 SCC 52, [2004] 3 S.C.R. 59) or the general police power to detain if reasonably necessary (see R. v. Clayton, 2007 SCC 32, [2007] 2 S.C.R. 725; R. v. Aucoin, 2012 SCC 66, [2012] 3 S.C.R. 408). While more limited detentions may give rise to their own powers to search, those powers are much more circumscribed in their scope and intrusiveness than search incident to arrest.[Emphasis by PJM]

[60] In recognition of their significance, this Court has hesitated to expand the scope of police arrest powers. For example, in Fleming this Court declined to recognize a common law power for the police to arrest lawfully acting individuals to prevent an apprehended breach of the peace (para. 88). The Court added that it had “difficulty seeing any need for the courts to fill a legislative gap by recognizing a common law power of arrest for the purpose of preventing individuals from committing breaches of the peace themselves” (para. 61). Similarly, in R. v. Feeney, [1997] 2 S.C.R. 13, this Court significantly curtailed the power of the police to effect warrantless arrests following forced entry into a private dwelling (para. 51).[Emphasis by PJM]

[65] This Court has also made clear that “[a]n arrest cannot be made solely for the purpose of investigation” (Feeney, at para. 35). Considerations such as the need to find and preserve evidence are irrelevant to the question of whether reasonable grounds for arrest exist (para. 30). The arrest power under s. 495 is not to be exercised for the investigation or prevention of criminal activity where an officer has no reasonable grounds to believe that an individual has committed or is about to commit an indictable offence (see R. v. Storrey, [1990] 1 S.C.R. 241, at p. 250; Feeney, at para. 29).

[66] The law of warrantless searches incident to arrest is also tightly circumscribed and ensures that the power is exercised for specific purposes. While searches incident to arrest can be conducted to address officer or public safety concerns arising from taking a person into custody or to discover and preserve evidence, those purposes must still be truly incidental to the arrest (R. v. Caslake, [1998] 1 S.C.R. 51, at para. 19). As stated in Caslake, “the search is only justifiable if the purpose of the search is related to the purpose of the arrest” (para. 17). In addition, where the purpose is to discover or preserve evidence, that evidence must be related to the offence for which the person is being arrested (para. 22; see also Fearon, at paras. 76-78; Stairs, at paras. 78-81)

[67] The public always has an interest in removing drugs and firearms from the street, especially near a school. But our criminal law has been careful to circumscribe the scope and conditions of the police power to act in the public interest, and in particular the powers to arrest and to search. This is because the expansion of these powers poses a risk to civil liberties (see, e.g., R. v. Tim, 2022 SCC 12, [2022] 1 S.C.R. 234, at para. 30). [Emphasis by PJM]

[68] The powers to arrest and search involve the important individual human rights of privacy and freedom from arbitrary detention protected under ss. 8 and 9 of the Charter. Police powers must be exercised lawfully and respecting the Charter rights of all people, including people who have called for emergency assistance. The scope of lawful police powers is not defined simply by the general scope of officers’ duties to investigate crime in the public interest (see MacDonald, at para. 38, citing Wiretap Reference, [1984] 2 S.C.R. 697, at pp. 718-19, per Dickson J., dissenting). Other police powers provide the tools to deal with exigent circumstances or public safety concerns if the conditions for their use are met.

[69] Therefore, I do not accept, as the Crown argues, that Parliament intended to allow the police to arrest and search good Samaritans on the grounds that an offence of simple possession was committed, despite making that offence immune from prosecution under s. 4.1(2) of the CDSA (A.F., at para. 57). The Crown’s proposition would suggest that Parliament intended, in enacting s. 4.1(2), to preserve the ability of the police to arrest good Samaritans for the offence of possession as a pretext for broader criminal investigations and searches that would otherwise be unlawful under principled limits to other police powers set out by this Court.

(4) Conclusion on the Statutory Interpretation of Section 4.1(2)

[71] For these reasons, I conclude that, by necessary implication, s. 4.1(2) of the CDSA provides immunity not just from charge and conviction for simple possession, but also from arrest for such a charge. Parliament’s aim was to save lives, and it created an immunity to encourage those at the scene of an overdose to call for life-saving emergency services. In providing immunity from charge and conviction for simple possession, Parliament intended to create an exception to the use of the police power of arrest for that offence. It recognized that those most likely to call for emergency assistance in life-threatening overdose situations will often themselves be drug users: not all good Samaritans will be law-abiding.

C. Lawful Powers of the Police at the Scene of a Drug Overdose

[73] First, the police can secure the scene and ask questions about the overdose that may help with the medical treatment required, prevent the use of tainted drugs by others, or identify the source of contaminated drugs that could pose further risks of overdose. As this Court said in R. v. Grant, 2009 SCC 32, [2009] 2 S.C.R. 353, “a police officer who attends at a medical emergency on a 911 call is not detaining the individuals he or she encounters. This is so even if the police, in taking control of the situation, effectively interfere with an individual’s freedom of movement” or question bystanders to “obtain information that may assist in their investigation” (paras. 36-37). Such questions may be more readily answered by people who have remained at the scene when they have a clear immunity from arrest for possession offences covered by s. 4.1(2).

[74] Second, this Court has established that the police have the power to detain individuals “where it is reasonably necessary in the totality of the circumstances”, weighing the seriousness of the risk to public or individual safety against the liberty interests of members of the public at the scene (Aucoin, at para. 36, citing Clayton, at para. 31).

[75] Third, the police can still exercise a substantial number of search and seizure powers when responding to an overdose. For example, under the plain view seizure power, the police can seize drugs and other items which were obtained by the commission of an offence and which are out in the open (Criminal Code , s. 489(2)). The police can also search a person to seize firearms and other weapons under the terms of s. 117.04(2) of the Criminal Code . Further, in MacDonald, this Court established that the police may conduct a safety search where it “is reasonably necessary to eliminate an imminent threat to the safety of the public or the police” (para. 40; see also para. 41). And where exigent circumstances are present and make it impracticable to obtain a warrant, the police can exercise their power of warrantless search under s. 487.11 of the Criminal Code and search for and seize controlled substances both in places and on people under s. 11(7) of the CDSA (see generally R. v. Paterson, 2017 SCC 15, [2017] 1 S.C.R. 202; R. v. Campbell, 2024 SCC 42). It would therefore be wrong to say that the police are prohibited from searching for weapons and drugs to protect themselves and the public at the scene of an overdose.

[76] Finally, all arrest and detention powers outside the scope of the s. 4.1(2) immunity remain available to the police…

D. Application

(1) Sections 8 and 9 of the Charter

[81] I have concluded that s. 4.1(2) of the CDSA includes immunity from arrest for possession of a controlled substance. There is no dispute that Mr. Wilson remained at the scene of a medical emergency within the meaning of s. 4.1, nor that the evidence supporting his initial arrest was obtained or discovered as a result. So, the issue is whether his initial arrest was an unlawful arrest for simple possession or whether it was carried out for a purpose that is authorized by law. A detention which is not authorized by law is arbitrary and violates s. 9 of the Charter (Grant, at para. 54). Furthermore, because the legality of a search incident to arrest depends on the legality of the arrest, a search based on an illegal arrest will necessarily be an infringement of s. 8 (Caslake, at para. 13).

[83] Although the trial judge’s reasons did not contain explicit findings of all the relevant facts, he stated that he “found the testimony of the police officers to be both credible and reliable” (A.R., at p. 21) and that “Constable Marshall first detained the three individuals for [an] investigative purpose. Once she saw a white powder which she believed was crystal meth, she arrested them for possession of a drug” (p. 15)…

[84] The only interpretation available on the evidence is that Mr. Wilson was arrested for possession of a controlled substance contrary to s. 4(1) of the CDSA and that the subsequent search which discovered the evidence of drug trafficking and the firearms was conducted incidentally to that arrest.

[86] Constable Marshall was clear in describing the observations she made at the scene which formed the basis for the initial detention and arrest. These observations included the information from the EMS responder that Ms. Delorme had overdosed on fentanyl; the smell of marijuana; the indicia of drug intoxication; and the small quantities of drugs she saw on the ground near the truck and near Mr. Wilson (A.R., at pp. 88-89, 93, 108 and 135-38). She saw nothing that would provide reasonable grounds to arrest for drug trafficking or firearms offences — those grounds did not exist until the search was conducted…

[87] Therefore, because s. 4.1(2) immunizes eligible individuals from arrest for simple possession, based on the record here, the arrest of Mr. Wilson was unlawful and breached his s. 9 right…

…In turn, this means that the search incident to that arrest was not authorized by law and was a breach of Mr. Wilson’s s. 8 right.

(2) Section 24(2) of the Charter

[91] I agree with the conclusions of the Court of Appeal. Given the seriousness of the breach of the Charter rights and the impact of that violation on Mr. Wilson’s Charter-protected interests, the evidence must be excluded under s. 24(2). Without that evidence, the record is insufficient to permit any trial court to convict, and Mr. Wilson must therefore be acquitted.

[93] Mr. Wilson had immunity under s. 4.1(2) when he was arrested for possession. Arresting him despite his immunity was a serious breach of his Charter rights that warrants the exclusion of evidence gathered consequent to the arrest. The Court of Appeal was right in the circumstances to enter acquittals on all charges.

[94] I would dismiss the appeal.

R v Ukuqtunnuaq, 2025 NUCA 8

[October 22, 2025] Fresh Evidence on Appeal [Suzanne Duncan, Alice Woolley, and Kevin Feth JJ.A.]

AUTHOR’S NOTE: Fresh Evidence After Guilty Plea – Capacity to Consent Reconsidered

Occasionally, key evidence emerges only after a guilty plea and sentencing have concluded. In this case, the accused had no memory of the incident, and the proceedings proceeded on the assumption that the complainant was incapable of consenting due to intoxication and blackout.

After conviction, a family member came forward who had personally observed the accused and complainant engaged in sexual activity that evening. The description — including that the complainant was on top and active during intercourse — was directly relevant to the question of capacity and consent.

While due diligence in discovering new evidence is a strict requirement in civil cases, criminal law applies a relaxed standard in recognition of the stakes and the need to avoid wrongful convictions. Here, the new evidence was both credible and potentially decisive, calling into question the factual foundation of the plea. The Court ordered a new trial on that basis.

Takeaway:
Even after a guilty plea, fresh evidence that materially undermines the basis for conviction — particularly on issues of consent and capacity — can justify reopening the matter. The criminal justice system prioritizes accuracy over finality when fresh, credible, and relevant evidence comes to light.

Overview

[1] This is an appeal from a sexual assault conviction based on an application to admit fresh evidence. At trial, the appellant Johnny Ukuqtunnuaq admitted the complainant’s statement that he sexually assaulted her in her home while she was sleeping the night of December 21, 2021. According to his counsel at trial, the appellant admitted the statement because he had no recollection of the evening in question as he was intoxicated. The appellant called no evidence. The trial judge found the complainant could not have consented because she was not conscious. The appellant was found guilty of one count of sexual assault and sentenced to 30 months in custody.

[2] The appellant seeks to have an affidavit from a family member admitted as fresh evidence on appeal. The family member describes certain observations of the incident that contradict the evidence of the complainant.

[3] The Crown concedes the evidence is relevant, credible, and, if believed, could reasonably be expected to have affected the outcome of the proceeding. The only issue the Crown contests is whether the appellant has met the due diligence criterion for the admission of fresh evidence on appeal. The Crown argues the appellant has not met his obligation to explain why the fresh evidence was not available at trial. According to the Crown, in this case, the importance of finality in the criminal process outweighs the appellant’s interest in having his guilt or innocence determined based on all the available evidence.

[4] For the reasons that follow, we grant the appellant’s application to adduce fresh evidence, allow the appeal, and order a new trial.

Law

[5] Section 683(1)(d) of the Criminal Code, RSC 1985, c C-46 addresses the admission of fresh evidence on appeal:

For the purposes of an appeal under this Part, the court of appeal may, where it considers it in the interests of justice,… (d) receive the evidence, if tendered, of any witness, including the appellant, who is a competent but not compellable witness…

[6] The overriding consideration on an application to adduce fresh evidence is “the interests of justice”. This requires a determination of due diligence, relevance, credibility and probative value: Palmer v The Queen, [1980] 1 SCR 759 at 775 [Palmer]; R v Hay, 2013 SCC 61 at para 63 [Hay]; R v Bharwani, 2025 SCC 26 at para 102. These factors strike a balance between two foundational principles – (i) reaching a just result in the context of the proceedings; and (ii) finality and order in the justice system: Barendregt v Grebliunas, 2022 SCC 22 at paras 32, 47 [Grebliunas].

[7] The relevance, credibility and probative value criteria are conditions precedent to the admission of evidence on appeal: Grebliunas at para 44; R v Lévesque, 2000 SCC 47 at para 14 [Lévesque]. They are concerned with reaching a just result: Grebliunas at paras 32, 45. To be relevant, the evidence must bear “upon a decisive or potentially decisive issue in the trial”. To be credible, the evidence must be “reasonably capable of belief”. To have sufficient probative value, the evidence “must be such that if believed it could reasonably, when taken with the other evidence adduced at trial, be expected to have affected the result”: Palmer at 775.

[8] The due diligence criterion means that “evidence should generally not be admitted if, by due diligence, it could have been adduced at trial”: Palmer at 775. It is not a prerequisite for the admission of fresh evidence on appeal, particularly in criminal cases. Nevertheless, it is an important factor that must be taken into account in determining whether it is in the interests of justice to admit or exclude the evidence: Lévesque at paras 15, 19; R v GDB, 2000 SCC 22 at para 19 [GDB]. It exists to ensure finality and order – values essential to the integrity of the criminal justice process: Hay at para 64; Grebliunas at paras 32, 37, 43. Routine admission of evidence on appeal that could have been adduced at trial would not be in the interests of justice: R v Truscott, 2007 ONCA 575 at para 101; Lévesque at para 19. An appellate court should consider the reason why the evidence was not presented at trial: Hay at para 64; GDB at paras 19, 20. The focus is on the conduct of the party seeking to adduce the evidence: Grebliunas at paras 36, 43.[Emphasis by PJM]

[9] An appellate court’s discretion in criminal matters to admit fresh evidence on appeal even where due diligence is not established is wider in scope than in civil matters. Failure to meet the due diligence criterion should not be used to deny admission of fresh evidence on appeal if that evidence is compelling and it is in the interests of justice to admit it: Lévesque at para 15; R v Warsing, [1998] 3 SCR 579 at para 51 [Warsing]; Palmer at 775; McMartin v The Queen, [1964] SCR 484 at 491 [McMartin].

Analysis

[10] The appellant’s family member states in his affidavit that in December 2021 he lived in the same house as the complainant. He was not aware of the details of the appellant’s charge or the allegations against him at trial until a week or two after the appellant had been sentenced and incarcerated, when the appellant asked him if he had seen anything. Before that, the family member had not told the appellant what he had observed.

[11] The family member attests that on the night in question, the complainant’s bedroom door was open and he briefly saw the appellant and complainant having sexual intercourse on the bed. The complainant was on top and the appellant on the bottom. Both of them looked at him. He then left the house. As he was leaving, he heard the complainant begin to yell and tell the appellant to go away.

[12] This evidence complies with the rules of evidence and is admissible. It consists of direct observations, no hearsay, no prior consistent statement, or other inadmissible content. As the Crown rightly concedes, the three conditions precedent set out in Palmer are satisfied. The evidence is relevant as it contradicts the complainant’s statement that she was sleeping when the assault began….

[13] The only questions are whether, through due diligence, the appellant could have adduced the evidence at trial and, if so, whether the interests of justice nevertheless favour admission on appeal.

[14] At the time of trial, the appellant was not aware that his family member had observed anything. His counsel told the trial judge the appellant had “no recollection” of the night in question. His family member attests, “I had not told [the appellant] what I observed that night”. The police did not interview anyone else in the household about the incident. No information was provided through disclosure to the appellant about who else was in the home that evening apart from the complainant’s statement that she initially thought the movement in her bed was her children.[Emphasis by PJM]

[15] In the circumstances, we are satisfied that due diligence in this case did not require the appellant to make inquiries with the family member. But even if such inquiries were required to meet the due diligence criterion, it would nevertheless be in the interests of justice to admit the evidence, given the appellant’s lack of awareness of the evidence at the time of his trial, the compelling nature of the evidence, and the serious nature of the charge: Hay at para 67; Lévesque at para 15, Warsing at para 51, and McMartin at 491. This is not a case like GDB at para 17 where a “tactical” decision by defence counsel was made.

Conclusion

[16] In all of the circumstances, it is in the interests of justice to admit the evidence. The application to admit fresh evidence is granted and the appeal is allowed. The fresh evidence is not so decisive as to allow for an immediate disposition of the matter. Therefore, the appropriate remedy is a new trial: Hay at paras 76-78. The matter is remanded for a retrial.

R v Liu, 2025 SKCA 98

[October 2, 2025] Expert Evidence: Overview of Admissibility Process [Reasons by Drennan J.A. with Robert W. Leurer C.J. and Keith D. Kilback J.A. concurring.]

AUTHOR’S NOTE: Trial errors on expert admissibility — a step-by-step corrective note

This decision is a useful reminder that procedural shortcuts at voir dire are not harmless — they can fatally undermine the reliability of expert evidence and the fairness of a trial. The trial judge here made a series of avoidable errors in the admissibility process for a proposed drug-expert, and the appellate guidance walks through each misstep.

Key errors identified:

Failing to hold a voir dire before admitting expert opinion — the judge never convened the required threshold inquiry into admissibility.
Preventing meaningful testing of qualifications — the accused was blocked from examining the expert on his claimed expertise.
Denying time to consider an expanded statement of qualifications — the defence was not afforded adequate opportunity to review new material about the expert.
Refusing access to the CV (with interpreter assistance) — where an accused is self-represented and requires an interpreter, procedural accommodations are essential; denying them adequate time to review a CV undermines fairness.
Failing to conduct or articulate the R v Mohan analysis — the judge omitted the required steps assessing relevance, necessity, absence of exclusionary rules, and proper expert methodology.

Observations and practical principles:

A busy docket or an unrepresented litigant does not excuse the court from carrying out rigorous admissibility procedures. If anything, additional care is required when procedural imbalances (self-representation, interpreter needs) are present.
Expert admissibility is not a mere formality: the trial judge must actively ensure the party seeking to call the expert establishes the requisite foundation and that the opponent is given a fair opportunity to test it.
Courts should explicitly apply the Mohan factors (and articulate the reasoning) before admitting opinion evidence so that appellate review can meaningfully assess the threshold decision.

Takeaway:
Procedural protections for expert evidence are substantive safeguards of trial fairness. Shortcutting them—especially against a self-represented accused who needs interpretation—risks reversible error. Trial judges must pause, hold the voir dire, permit testing of qualifications, provide translation/time where needed, and state the Mohan analysis on the record.

I. INTRODUCTION

[1] Diexin Liu was driving from Calgary to Toronto when he was stopped near Swift Current by a Saskatchewan Highway Patrol officer. He had approximately five kilograms of cannabis and growing equipment in his car.

[2] Following a trial in Provincial Court, Mr. Liu was convicted of three offences contrary to the Cannabis Act, SC 2018, c 16: (a) unlawfully possessing more than 30 grams of dried cannabis in a public place contrary to s. 8(1)(a); (b) possessing cannabis for the purpose of distribution contrary to s. 9(2); and (c) possessing cannabis for the purpose of sale contrary to s. 10(2). He was also convicted of possessing unstamped cannabis product contrary to s. 158.11 of the Excise Act, 2001, SC 2002, c 22. Under the Excise Act, the absence of a stamp indicates that applicable federal and provincial duties on the product have not been paid.

[3] Mr. Liu…

….contends the trial judge erred in admitting certain expert opinion evidence, which compromised his ability to make full answer and defence, and that the reasons for conviction on the Excise Act count were insufficient and linked to an error in law….

[4] As I will now explain, I agree with Mr. Liu’s submission that the trial judge erred in admitting Sgt. Karaim’s opinion evidence. In that process, he also erred in limiting Mr. Liu’s ability to make full answer and defence. These errors resulted cumulatively in a miscarriage of justice and a substantial wrong in connection with the conviction on the distribution and sale counts that cannot be remedied by the curative proviso under s. 686(1)(b)(iii) of the Criminal Code….

II. BACKGROUND

[5] On May 5, 2021, a Saskatchewan Highway Patrol officer stopped Mr. Liu to check on his sobriety, driver’s licence, and registration. The vehicle Mr. Liu was driving also had tinted front side windows, which the officer believed to be unlawful.

[6] When speaking with Mr. Liu, the officer noticed a package of unstamped tobacco in plain view and called the Royal Canadian Mounted Police to assist. An RCMP officer arrived and arrested Mr. Liu. The vehicle was searched incidentally to the arrest and officers found 5.094 kilograms, or 11.23 pounds, of cannabis along with equipment commonly used for growing marijuana. Also in the vehicle were clothes, personal belongings, and identification documents belonging to Mr. Liu, who claimed to be driving through Saskatchewan in the process of moving from Calgary to Toronto.

[7] The cannabis was packaged in five vacuum-sealed bags, each weighing between 472 and 480 grams, or approximately one pound. A sixth vacuum-sealed bag contained 30 grams of cannabis. Two other bags contained marijuana stalks and leaves weighing 1.47 and 1.64 kilograms respectively. The seized equipment included five grow lights, humidifiers, fans, water supply systems, and a grow tent.

[8]….Mr. Liu proceeded to represent himself at trial, with the assistance of a Mandarin interpreter.

[9] At trial, the Crown tendered Sgt. Karaim as an expert witness. Several aspects of the process surrounding the admission of his evidence, which will be further detailed below, bear mention at this point:

(a) although the trial judge stated that a voir dire was not required to qualify Sgt. Karaim as an expert, he went on to address Sgt. Karaim’s qualifications before allowing him to give opinion evidence;

(b) the Crown’s notice of expert witness stated that Sgt. Karaim was tendered to give expert opinion evidence on (i) methods of production, packaging, distribution, and pricing of cannabis, (ii) the effects, usage, and availability of cannabis, and (iii) the language and paraphernalia connected to the possession, use, and distribution of cannabis. At the commencement of the trial, Crown counsel sought an addendum to the proposed areas of qualification to include opinion evidence on the “sale of cannabis… including the purpose for which cannabis is possessed in a particular case”;

(c) at the outset of the qualification process, Mr. Liu advised the trial judge that he had not received and reviewed Sgt. Karaim’s CV. The CV was 17 pages in length. The judge adjourned the matter for approximately 20 minutes so that Mr. Liu could review the document with the interpreter but indicated it was not necessary to interpret every word;

(e) Mr. Liu attempted to ask Sgt. Karaim two questions during the qualification process, related to how Sgt. Karaim knew that he (Mr. Liu) was selling cannabis. The trial judge interjected, saying it was “too early to ask them”.

[10] The trial judge ultimately qualified Sgt. Karaim in all areas proposed by the Crown, including the expanded scope of qualification, based largely on his CV and affidavit. A report prepared by Sgt. Karaim was subsequently entered into evidence. In that report, Sgt. Karaim provided the opinion that Mr. Liu had the cannabis in his possession for the purpose of distribution and sale. This opinion was based on several factors set out in the report and in Sgt. Karaim’s testimony, including that:

(a) a heavy cannabis user would consume a maximum of two grams per day;

(b) at that rate, it would take approximately six-and-a-half years to consume the quantity of cannabis that had been seized from Mr. Liu;

(c) the way the cannabis was packaged (in vacuum-sealed one-pound bags) is consistent with preparation for sale at the pound level and not consistent with packaging for personal use;

(d) the value of the cannabis was between $17,000 and $22,000;

(e) cannabis is readily available at retail locations and there is no need to stockpile it for personal use; and

(f) cannabis dries out and degrades over time, so users typically hold only small amounts for personal consumption to ensure it is fresh and potent.

[13] Mr. Liu testified that he had grown so much cannabis because it was expensive to buy in stores. He explained that he had packaged some of the cannabis in one-pound bags so that he would know how much he had, though he was unable to say how long one pound would last him. Mr. Liu did not know whether he was required to have a license or to pay tax on the cannabis he had grown.

[14] The trial judge accepted Sgt. Karaim’s evidence, found Mr. Liu’s explanation for why he possessed such a large quantity of cannabis to lack credibility, and convicted him of all the charge.

[15] The trial judge sentenced Mr. Liu to serve 13 months imprisonment concurrent on the distribution and sale counts, and four months on the possession count to be served concurrently. The judge also imposed a fine of $10,525 on the Excise Act count.

IV. ANALYSIS

A. Did the trial judge err by admitting the expert opinion evidence of Sgt. Karaim?

2. The trial judge erred in admitting Sgt. Karaim’s opinion evidence

[19] Cutting to the bottom line, I agree with Mr. Liu that the trial judge committed several interconnected errors in the qualification of Sgt. Karaim and the admission of his evidence. A number of aspects of the record lead to this conclusion and are also relevant to the Crown’s submission on the curative proviso.

[20] To understand my concerns in this regard, it is important to keep in mind that in order for Sgt. Karaim’s evidence to have properly been received as expert opinion, the Crown was required to establish his qualifications and the trial judge was required to determine the nature and scope of the proposed expert evidence (see R v Abbey, 2009 ONCA 624 at para 62, 246 CCC (3d) 301; R v Sekhon, 2014 SCC 15 at para 46, [2014] 1 SCR 272). Since Sgt. Karaim’s qualifications were not admitted, this would normally be expected to have been done in a voir dire, with Mr. Liu having the opportunity to cross-examine him on his proposed expertise in that forum (David Watt, Manual of Criminal Evidence (Toronto: Thomson Reuters, 2024) at §5:2). After determining the boundaries of the proposed expert opinion Sgt. Karaim was qualified to provide, the trial judge was then required to apply the two-part test for the admission of expert evidence set out in White Burgess at paras 23–24; Mohan; and R v Bingley, 2017 SCC 12 at para 14, [2017] 1 SCR 170. Under this framework, the first step calls for a trial judge to determine whether the proposed evidence satisfies the four Mohan criteria (relevance; necessity; absence of an exclusionary rule; and a properly qualified expert). At the second step, the trial judge is to perform a gatekeeper role and consider whether the benefits of admitting the evidence outweigh the potential risks in doing so.

[22] First, while not necessarily indicative of error in and of itself, it is problematic that, given Sgt. Karaim’s qualifications were not admitted, the trial judge did not conduct a voir dire to consider those qualifications. Indeed, he appeared to not understand the need for a voir dire in such a circumstance. When asked by Crown counsel at the outset of Sgt. Karaim’s qualification process if a voir dire was required, the trial judge said: “I’m trying to think here, I don’t think we have to go into a voir dire, you just have to qualify him. If he doesn’t get qualified, he doesn’t get qualified”. While the trial judge ultimately considered Sgt. Karaim’s qualifications before allowing him to provide opinion evidence, the trial judge’s somewhat cavalier approach to the qualification process creates genuine doubt as to his understanding of the method by which an expert is qualified to do so.

[23] Second, the process followed by the trial judge deprived Mr. Liu of any real notice of the Crown’s intent to elicit expert testimony on the key issue in the trial. In this regard, it is to be recalled that the Crown tendered Sgt. Karaim to give expert opinion evidence on (a) methods of production, packaging, distribution, and pricing of cannabis, (b) the effects, usage, and availability of cannabis, and (c) the language and paraphernalia connected to the possession, use, and distribution of cannabis. However, as previously mentioned, at the commencement of Sgt. Karaim’s examination in chief, Crown counsel orally sought an addendum to the qualification, proposing that Sgt. Karaim be qualified to also give opinion evidence on the “sale of cannabis… including the purpose for which cannabis is possessed in a particular case”. This mid-trial addendum deprived Mr. Liu of the notice required by s. 657.3(3) of the Criminal Code, and was of particular significance to Mr. Liu because the new proposed area of expertise went to the ultimate issue, being whether Mr. Liu possessed cannabis for the purpose of sale and distribution.[Emphasis by PJM]

[24] Third, the trial judge qualified Sgt. Karaim based on evidence that was not accessible to Mr. Liu in a practical way. It is important to recall that Sgt. Karaim was largely qualified based on his 17-page CV, which Mr. Liu said he had not seen before the trial. In response to the Crown’s suggestion that the interpreter translate the entire CV, the trial judge responded that such an exercise, given the length of the CV, would likely take “a couple days”. He instead adjourned the hearing for approximately 20 minutes to allow Mr. Liu to review it with the interpreter, indicating on the record that “we won’t interpret every word”. After the adjournment, Crown counsel attempted to elicit viva voce evidence from Sgt. Karaim on the “summary of service” portion of his CV. The trial judge interrupted, saying “once [counsel] put a document [the CV] in, it’s in, I’ll read it, and, so, there’s no need to go through it and just repeat what I’m going to read anyway”. The combination of the limited time given to Mr. Liu to review the CV with the interpreter, and the trial judge’s interjection which had the effect of curtailing Crown counsel from leading viva voce evidence on Sgt. Karaim’s education, training, and experience relevant to his qualifications, cumulatively leads me to conclude that Sgt. Karaim was qualified without his qualifications being fully presented to Mr. Liu.

[25] Fourth, Mr. Liu was deprived of the ability to question Sgt. Karaim on his qualifications. The trial judge acknowledged earlier in his reasons that the Crown bore the onus of demonstrating that Sgt. Karaim was an expert and that questions could be asked of him to flesh out his purported expertise, or lack thereof. However, Mr. Liu was prevented from asking questions related directly to the officer’s qualifications to opine on the maximum cannabis consumption rates and the basis of the officer’s opinion that Mr. Liu possessed the cannabis for the purpose of distribution or sale. This is reflected in the following exchange:

THE INTERPRETER: So, is it true that the maximum individual — the maximum amount an individual can consume cannabis is 2 grams per day?

THE COURT: Okay, so, tell Mr. Liu, those are good questions, but it’s too early to ask them.

THE INTERPRETER: Oh.

THE COURT: I have to determine if he can testify as an expert first. So, does Mr. Liu have any questions about his qualifications?

THE INTERPRETER: So, he is not sure what question to ask about the qualification of the expert.

[26] Fifth, stepping outside of the qualification stage, the trial judge failed to consider if Sgt. Karaim’s proposed testimony met the four-part Mohan test. In this regard, after precluding Mr. Liu from asking the above questions, the trial judge proceeded to qualify Sgt. Karaim on the basis of his CV without any reference to or analysis of the threshold requirements for the admissibility of Sgt. Karaim’s opinion as set out in Mohan and without weighing the benefits and risks of its admission:

THE COURT: So, no questions as to his being qualified as an expert? Okay. So, my ruling is that this witness, which is Sergeant Karaim is qualified as an expert to give expert evidence on the methods of production, packaging, distribution, and pricing of cannabis; the effects, usage, and availability of cannabis; the language and paraphernalia connected to the possession, use, and distribution of cannabis and sale of cannabis including for the purpose cannabis is possessed in a particular case.

And that is based on his resume, his curriculum vitae, that was file [sic] which outlines his education and his experience. …

[27] I would pause here to observe that there is nothing in the education or experience portion of Sgt. Karaim’s CV that spoke specifically to his education, training, or expertise in cannabis usage or consumption rates by an individual. As noted above, he also gave no viva voce evidence on this or any other aspect of his purported expertise.[Emphasis by PJM]

[28] The trial judge’s failure to conduct or provide any analysis of how Sgt. Karaim’s evidence satisfied the Mohan criteria, and his failure to weigh the benefits and risks of admitting his evidence, was an error in law (see R v SKM, 2021 ABCA 246 at para 61, [2021] 10 WWR 277; see also R v Montague-Mitchell, 2018 SKCA 78 at para 39, 368 CCC (3d) 322)….

[29] Sixth, the trial judge denied Mr. Liu the right to cross-examine Sgt. Karaim on a key area of his testimony, and one that the judge relied upon to convict. In this regard, Sgt. Karaim was permitted to offer the opinion that a heavy cannabis user would consume approximately two grams per day. He also gave evidence that the volume of cannabis seized from Mr. Liu and the manner in which it was packaged were consistent with distribution and not personal use. During his crossexamination of Sgt. Karaim, Mr. Liu inquired as to what indicia other than the nature of the packaging of the cannabis led the officer to conclude that the cannabis was intended for distribution. Sergeant Karaim answered in this way:

Yes. The — the total amount of cannabis is way beyond user level. To me, the amount of cannabis, if it’s used for smoking, which I believe this is, is somewhere between 4 and-ahalf to 6 years of smoking 20 hours a day.

…

Other evidence that states to me that it leads to distribution and selling is the total amount in excess of $10,000 up to $22,000, that’s not normal for someone to have just driving around.

[30] Mr. Liu then asked Sgt. Karaim to consider a scenario where he (Mr. Liu) was “moving [his] home” with the cannabis in his vehicle. The trial judge again intervened, preventing Mr. Liu from asking the question and characterizing it as one “for argument”. Later, following the close of Sgt. Karaim’s testimony, the trial judge advised Mr. Liu that if he intended to assert that he was moving and that the cannabis had been grown in his home, he would have to testify to that. As previously noted, Mr. Liu later testified that the plants and cannabis seized had been grown in his home as it was cheaper to do so, and that he was moving all of his possessions to Toronto (consistent with officer evidence at trial that Mr. Liu had his possessions and valuables in the vehicle). Amongst other things, Mr. Liu also testified during cross-examination to consuming approximately two to three grams of cannabis a day.

[31] The trial judge’s interruption of Mr. Liu’s cross-examination on a relevant line of inquiry was an error in principle. A failure to allow relevant cross-examination will almost always be grounds for a new trial, unless the curative proviso in s. 686(1)(b)(iii) of the Criminal Code applies (see R v R.V., 2019 SCC 41 at paras 84 and 86, [2019] 3 SCR 237; R v Shearing, 2002 SCC 58 at para 151, [2002] 3 SCR 33; R v Samaniego, 2022 SCC 9 at para 71, [2022] 1 SCR 71). As I will later explain, it had a related implication for Mr. Liu’s decision to testify.

[32] To summarize, the foregoing aspects of the record demonstrate that the trial judge erred by (a) failing to recognize the significance of the late notice to Mr. Liu of the Crown’s intention to have Sgt. Karaim qualified to give opinion evidence on the ultimate issue, (b) qualifying Sgt. Karaim to give opinion evidence based on qualifications that were not transparently presented to Mr. Liu, (c) depriving Mr. Liu of the ability to cross-examine Sgt. Karaim on his qualifications, (d) failing to conduct or provide any analysis of how Sgt. Karaim’s evidence satisfied the Mohan criteria, and failing to weigh the benefits and risks of admitting his evidence, (e) failing to properly scrutinize Sgt. Karaim’s opinion approaching the ultimate issue, and (f) preventing Mr. Liu from pursuing a relevant line of cross-examination of Sgt. Karaim when he provided his opinion evidence. In short, the trial judge’s complete failure to properly apply the rules that govern the admission of opinion evidence, coupled with his interference in Mr. Liu’s cross-examination of Sgt. Karaim, amount to errors in law and principle warranting appellate intervention pursuant to s. 686(1)(a).

[42] I would therefore quash Mr. Liu’s convictions on the distribution and sale counts and remit them for a new trial.

V. CONCLUSION

[75] To summarize and conclude, I would allow Mr. Liu’s appeal respecting the distribution and sale counts, quash his convictions, and remit those matters for trial. I would not interfere with his conviction on the Excise Act count. On the possession count conviction, I would grant him leave to appeal sentence and vary his sentence to be one of a 12-month conditional discharge, with the single condition being that he keep the peace and be of good behaviour.

Also on the Blog

The Defence Toolkit – November 22, 2025: Functioning Technology

This week's top three summaries: R v Bjil, 2025 SKCA 116: #technology, R v Lessard, 2025 ONCA 760: #NCRMD, R v Krelove, 2025 ONSC 6004: #domestic...

The Defence Toolkit – November 15, 2025: Remand Retribution

This week's top three summaries: R v Whitlock, 2025 ONSC 6006: #remand s.12, R v EJ, 2025 ONSC 6016: #self-defence, R v CB, 2025 ONSC 6004:...

The Defence Toolkit- November 8, 2025: Mandatory Minimums

This week's top three summaries: Quebec (AG) v Senneville, 2025 SCC 33: min #sentence, R v Hutton, 2025 ABCA 356: 271 mens rea, R v Backfat, 2025...



About Us

Working through your complex trial materials

Our lawyers have been litigating criminal trials and appeals for over 16 years in courtrooms throughout Canada. We can be of assistance to your practice. Whether you are looking for an appeal referral or some help with a complex written argument, our firm may be able to help. Our firm provides the following services available to other lawyers for referrals or contract work:

Please review the rest of the website to see if our services are right for you.

Pawel Milczarek, Appellate Lawyer in Calgary, AB.

Written By Pawel Milczarek

Pawel is a partner at Sitar & Milczarek. When he’s not litigating he writes the Defence Toolkit blog.

The Defence Toolkit – October 25, 2025: Expert Experience and Bias

This week's top three summaries: R v Matthews, 2025 ABKB 597: #expert bias, R v RL, 2025 ONCA 691: #acquittal appeal, R v Wilson, 2025 ABCA 337: #contempt R. v. Matthews, 2025 ABKB 597 [October 14, 2025] Expert Evidence: Experience and Bias [Justice Lisa A. Silver]...

The Defence Toolkit – June 28, 2025: Ares v. Venner and Expert Evidence

This week's top three summaries: R v Willier, 2025 ABKB 370: Ares v Venner #Expert Evidence, R v Zabihullah, 2025 SKCA 64: 11(b) particular #complexity, R v Moazami, 2025 BCCA 189: trial #aggravating sentence R v Willier, 2025 ABKB 370 [June 18, 2025] The Common Law...

The Defence Toolkit – June 14, 2025: Expert Evidence

This week's top three summaries: R v Whitby, 2025 SKCA 55: #expert evidence, R v Herman-Ward, 2025 ABCJ 101:s.10(b) #perfunctory, R v McQuarrie, 2025 ONSC 2955: #prisoner disclosure R v Whitby, 2025 SKCA 55 [June 6, 2025] Expert Evidence Admissibility: Testing of...