WARNING THIS IS AN APPEAL UNDER THE YOUTH CRIMINAL JUSTICE ACT AND IS SUBJECT TO:

111(1) Subject to this section, no person shall publish the name of a child or young person, or any other information related to a child or a young person, if it would identify the child or young person as having been a victim of, or as having appeared as a witness in connection with, an offence committed or alleged to have been committed by a young person.

138(1) Every person who contravenes subsection 110(1) (identity of offender not to be published), 111(1) (identity of victim or witness not to be published), 118(1) (no access to records unless authorized) or 128(3) (disposal of R.C.M.P. records) or section 129 (no subsequent disclosure) of this Act, or subsection 38(1) (identity not to be published), (1.12) (no subsequent disclosure), (1.14) (no subsequent disclosure by school) or (1.15) (information to be kept separate), 45(2) (destruction of records) or 46(1) (prohibition against disclosure) of the Young Offenders Act , chapter Y-1 of the Revised Statutes of Canada, 1985,

(a) is guilty of an indictable offence and liable to imprisonment for a term not exceeding two years; or

(b) is guilty of an offence punishable on summary conviction.

COURT OF APPEAL FOR ONTARIO

DATE: 20210525

DOCKET: C65486 & C64579

Rouleau, van Rensburg and Miller JJ.A.

BETWEEN

Her Majesty the Queen Respondent

and

Derek Oppong Appellant

AND BETWEEN

Her Majesty the Queen Respondent

and

Akido Thomas Appellant

Counsel: Dirk Derstine, for the appellant Derek Oppong Akido Thomas, appearing in person Geoff Haskell, for the appellant Akido Thomas, pursuant to a limited order under s. 684 of the Criminal Code Amy Alyea, for the respondent

Heard: January 14, 2021 by video conference

On appeal from the conviction entered on June 8, 2017 by Justice Robert F. Goldstein of the Superior Court of Justice, sitting with a jury, and the sentence imposed on November 6, 2017, with reasons reported at 2017 ONSC 6684 (C65486).

On appeal from the conviction entered on June 8, 2017 by Justice Robert F. Goldstein of the Superior Court of Justice, sitting with a jury (C64579).

van Rensburg J.A.:

I OVERVIEW

[1] The appellants and a co-accused, Raheem Thomas-Stewart, were tried before judge and jury and convicted of having committed various kidnapping-related offences with a firearm at the direction of or for the benefit of a criminal organization. Mr. Oppong was acquitted of attempted murder. Mr. Oppong was sentenced to 11 years in prison, less credit for four years’ pre-sentence custody. Mr. Thomas was sentenced to nine years, less credit for 52 months’ pre-sentence custody.

[2] Mr. Oppong appeals his conviction and seeks to appeal his sentence. Mr. Thomas appeals only his conviction, having withdrawn his sentence appeal at the hearing of the appeal. Mr. Thomas was represented by counsel on a limited retainer under s. 684 of the Criminal Code , R.S.C. 1985, c. C-46 .

[3] On their conviction appeals the appellants assert that the trial judge erred in admitting the opinion evidence of an expert witness relating to gang activity and discipline. They say that the trial judge erred in admitting the expert’s evidence, which was unnecessary and biased, and in failing to find that its prejudicial effect outweighed its probative value. In the alternative, they contend that the trial judge erred in refusing to exclude the expert evidence after a material change in circumstances: the proposed admission of certain facts that obviated the need for the expert evidence.

[4] In his sentence appeal, Mr. Oppong asserts that the trial judge made a finding that was not supported by the evidence – that he was a leader of a street gang called In Da Streets (“IDS”). Without this finding, he contends that he ought to have received the same sentence as Mr. Thomas. [1]

[5] For the reasons that follow, I would dismiss the conviction appeals and the sentence appeal.

[6] As I will explain, the trial judge made no reversible error in admitting the expert evidence in this case. He addressed the concerns raised by the defence, and exercised appropriate caution in admitting some, but not all, of the proposed expert evidence, and in limiting the specific items the expert was permitted to rely on when testifying, in order to avoid prejudice to the accused. The trial judge did not err in refusing to exclude the expert evidence on the basis of a material change in circumstances after the appellants’ counsel indicated that the appellants were prepared to admit certain facts. He reasonably concluded that the facts the appellants were prepared to admit did not alter the balance between the prejudicial effect and probative value of the expert evidence.

[7] As for the sentence appeal, contrary to Mr. Oppong’s argument, there was evidence to support the conclusion that he was a leader of IDS, and his sentence was entirely fit.

[8] In the reasons that follow, I will address the issues raised in the conviction appeals and then I will turn to Mr. Oppong’s sentence appeal.

II CONVICTION APPEALS

A. THE OFFENCE

[9] The charges arose out of an alleged incident between the appellants, their co-accused, and Dontay Haye, while they were all members of IDS, a street gang that operated in the Toronto neighbourhood of Jamestown.

[10] Mr. Haye, who was 16 years old at the time, claimed that on May 19, 2015 he was warned by friends that people were looking for him because they believed he had stolen one of the guns belonging to the gang. They suspected that Mr. Haye had taken the gun because he knew that the gun was normally hidden in a BBQ grill near the home of Mr. Haye’s best friend, A.M. Mr. Haye claimed that, as he was walking through the neighbourhood, he was approached by Mr. Thomas and Mr. Thomas-Stewart, who punched him in the face and chest. Mr. Thomas had a handgun and threatened to shoot him. They forced Mr. Haye to follow them to John Garland Blvd., where they met up with Mr. Oppong and several other men who assaulted him again. Mr. Oppong kept asking him where the gun was, and Mr. Haye kept saying that he did not have it.

[11] After the second assault, Mr. Oppong told Mr. Haye to get into a car. He drove Mr. Haye to a housing complex where Mr. Oppong told him that he could either bring back the gun or give him $2,500, or else he would be “flipped” (i.e.: killed). They walked toward a field near the housing complex where they were joined by A.M., who had a gun. Mr. Oppong told Mr. Haye that this was his last chance. As Mr. Haye started to run away, Mr. Oppong told A.M. to chase after and to shoot him. A.M. chased after Mr. Haye, but he did not shoot. Mr. Haye managed to escape. He ran to a nearby townhouse unit where he persuaded the occupant to call 911.

[12] Mr. Haye eventually entered the witness protection program and provided his account of the events to the police.

[13] The movements of the parties were captured by CCTV cameras. The defence theory at trial was that Mr. Haye fabricated the story about having been assaulted, threatened and kidnapped. The accused did not testify. The central issue was the credibility and reliability of Mr. Haye’s account.

B. THE EXPERT EVIDENCE

The Admissibility Ruling

[14] The Crown brought a pre-trial application seeking to admit expert opinion evidence from Detective Aman Nasser, [2] a Toronto police officer with considerable experience and knowledge of street gangs in Toronto.

[15] The Crown proposed that Detective Nasser would testify about the IDS gang and the general nature and activities of urban street gangs and their characteristics as “criminal organizations” within the definition of that term in s. 467.1(1) of the Criminal Code . Detective Nasser had prepared an expert report, in which he responded to three questions: (1) is IDS a “street gang”; (2) would IDS benefit from kidnapping Mr. Haye; and (3) are Mr. Oppong, Mr. Thomas, and Mr. Thomas-Stewart members of IDS?

[16] The Crown argued that the expert evidence was required to demonstrate essential elements of the criminal organization offences: that IDS is a criminal organization and that the kidnapping and assault of Mr. Haye would have benefited IDS. The Crown also submitted that the evidence assisted in understanding the context or narrative of the alleged offences.

[17] The application was opposed by the defence on the basis that the proposed expert evidence failed to meet the first two Mohan criteria of necessity and relevance: R. v. Mohan, [1994] 2 S.C.R. 9. They asserted that the evidence was unnecessary because Mr. Haye would be able to provide all the evidence needed to show that IDS is a street gang, and that the issues in the case went to credibility and were not such that the jury required additional context. The defence also argued for the exclusion of the evidence at the “gatekeeper” stage – that the probative value of the proposed expert evidence was outweighed by its prejudicial effect, failing the cost-benefit analysis set out in R. v. Abbey, 2009 ONCA 624, 97 O.R. (3d) 330, leave to appeal refused, [2010] S.C.C.A. No. 125.

[18] The application to introduce expert evidence, which included a voir dire in which the proposed expert testified, was heard over the course of four days. The trial judge provided an oral ruling in which he concluded that Detective Nasser’s expert evidence was admissible, although he limited the scope of such evidence. He provided a table of specific rulings on the admissibility of certain items of evidence that the expert could or could not refer to in his testimony.

[19] In the trial judge’s written reasons (reported at 2017 ONSC 3443 ), he concluded that the proposed expert evidence met the four Mohan criteria. He noted that defence counsel had conceded that Detective Nasser was a properly qualified expert and that there was no exclusionary rule that applied. In addressing the two contested criteria, the trial judge found that the proposed evidence was logically relevant and necessary. He stated:

I find that the evidence is logically relevant to [the] facts in issue: [Abbey], at para. 84 . The characteristics of street gangs and street gang ideology are relevant to understanding the context of the alleged offences. The expert evidence is also relevant to whether the assault and kidnapping of Mr. Haye (if his evidence is believed) was for the benefit of a criminal organization. Without the expert evidence, the jury will be left solely with the evidence of Dontay Haye. Dontay Haye may or may not give evidence regarding the use of violence by gangs to enforce discipline and communicate a message of obedience to the gang hierarchy.

Furthermore, Mr. Haye’s evidence is problematic, to say the least. Mr. Haye’s credibility will undoubtedly be subject to sustained assault in all respects. Without the context provided by the expert evidence, the jury will be left with his version of how gangs operate. The jury may well be left to puzzle over the purpose of an attempt to kidnap and beat Mr. Haye without context. The expert evidence will assist in evaluating his credibility (or lack of credibility).

[20] The trial judge then assessed whether the probative value of the proposed evidence outweighed its prejudicial effect. He recognized that the “gatekeeper function does not involve bright lines” and that “it requires an analysis of costs and benefits and sometimes does not yield a straightforward “yes” or “no” answer” (citing [Abbey], at para. 79 and R. v. Sheriffe, 2015 ONCA 880, 333 C.C.C. (3d) 330, at paras. 101-103 , 108, leave to appeal refused, [2016] S.C.C.A. No. 299). The trial judge reviewed a number of case authorities with respect to the assessment of the costs and benefits of evidence relating to gangs: [Abbey]; R. v. Riley, 2009 ONSC 15451, [2009] O.J. No. 1374 (Ont. Sup. Ct.); R. v. Williams, 2013 ONSC 1076. He noted that the assessment of the probative value of expert evidence involves consideration of the significance of the particular issue, as well as the reliability of the evidence, including the expert’s methodology, expertise and objectivity, while the cost of the evidence addresses the usual risk of prejudice in expert evidence, as well as the risk of complexity and the abdication of the jury’s function to the expert. The trial judge observed that proving criminal organization offences would inevitably involve bad character evidence. As such, steps must be taken to limit the evidence to what is relevant and necessary, and to give mid-trial and final instructions to place the evidence in context and obviate prejudice.

[21] In assessing the probative value of the evidence, the trial judge addressed defence counsel’s argument that Detective Nasser had shown a lack of objectivity because (1) he did not wish to engage with defence counsel on a particular issue outside the courtroom setting; and (2) his background work into certain incidents of gang association or indicia of gang membership involving the accused did not go far enough. The trial judge adverted to these concerns about Detective Nasser’s evidence and concluded that they would go to the weight to be given to his opinion by the jury.

[22] The trial judge limited the scope of the expert evidence. Detective Nasser was permitted to testify about the general characteristics of a street gang, the association of street gangs with particular neighbourhoods, methods that gang members use to identify themselves as members, gang ideology, and the use of violence by gangs to maintain discipline. He was not permitted to state as a fact that any of the three accused were members of IDS, although he was allowed to testify about particular associations, symbols and incidents that were consistent with membership in IDS or a street gang. Detective Nasser was not allowed to testify that the alleged kidnapping, assault and attempted murder of Mr. Haye would have benefitted IDS. The trial judge addressed the extent to which Detective Nasser could rely on confidential informant information, and he provided specific rulings on certain aspects of Detective Nasser’s proposed evidence, including the extent to which the expert was permitted to refer to various incidents involving gang members (including the appellants) and YouTube videos.

The Application to Revisit the Admissibility Ruling

[23] Before the trial proper began, and upon receipt of the trial judge’s written reasons, Mr. Oppong’s trial counsel raised the possibility of making certain concessions if the Crown agreed not to call Detective Nasser as a witness. The following day the trial judge heard a defence application to revisit his admissibility ruling based on a material change in circumstances, in light of the proposed admissions.

[24] The appellants were prepared to admit that IDS existed, that Mr. Oppong and Mr. Thomas were members of IDS, and that the acts (if they took place) were committed at the behest of a criminal organization. Mr. Thomas-Stewart was prepared to admit that IDS is a street gang, that association with other members is a characteristic of gang membership, and that he was in the company of certain gang members on specific dates (not including the date of the incident).

[25] Defence counsel argued that the proposed admissions extended beyond the scope of Detective Nasser’s permitted evidence and constituted a material change in circumstances. They asserted that with these admissions, the probative value of Detective Nasser’s evidence would need to be re-assessed, as it would now only serve to bolster Mr. Haye’s credibility. Counsel for Mr. Oppong also proposed that, if necessary, evidence on the general characteristics and circumstances of street gangs could be provided through an agreed statement of facts, although no agreement had been reached.

[26] The trial judge gave a brief oral ruling dismissing the application to revisit his ruling on the expert evidence, with written reasons released subsequently and reported at 2020 ONSC 7844 .

[27] The trial judge concluded that there was no basis to revisit his admissibility ruling. He stated that “the willingness of the defence to make some admissions did not constitute a material change of circumstances”. Citing the trial decision in R. v. Gager, 2012 ONSC 2697 (where a trial judge had revisited a ruling with respect to what evidence an expert on gangs could refer to in his evidence), the trial judge noted that, in order for the change of circumstances to be material, it must “alter the balance between the prejudicial effect and probative value” of the evidence.

[28] The trial judge observed that there was a significant difference between admitting facts pursuant to s. 655 of the Criminal Code and “admitting the thrust of expert evidence that goes to assisting the jury in understanding the context of the case”. He noted that the factual admissions the defence proposed to make did not assist the jury in understanding the context of Mr. Haye’s evidence. He concluded: “The key point about [Detective] Nasser’s evidence is that it is supposed to help the jury understand the background. The proposed admissions do nothing to advance the jury’s understanding without context”.

[29] The trial judge rejected the submission of Mr. Thomas’s counsel that the expert evidence was simply an attempt at oath-helping. He noted: “As I stated in my original ruling, the purpose of the expert evidence was to allow the jury to understand his evidence given the circumstances of a gang-related offence”. He went on to observe that, even if he had accepted that the proposed admissions were a material change, there would have been great difficulties in managing the trial where one of the accused was not prepared to make the same admissions as the other two.

[30] As for the argument that the general characteristics and circumstances of street gangs could be addressed through an agreed statement of facts, the trial judge observed that there was no such agreement, and that he had no power as a trial judge to compel a party to make a concession it was not otherwise prepared to make.

The Expert Evidence at Trial

[31] Detective Nasser was the Crown’s first witness at trial. In the course of his evidence, counsel for Mr. Oppong conceded his client’s membership in IDS and the Crown refrained from eliciting evidence from Detective Nasser regarding some (but not all) incidents in which Mr. Oppong was associating with known gang members. After Mr. Thomas’s counsel conceded his client’s membership in IDS, the Crown refrained from eliciting evidence from Detective Nasser regarding Mr. Thomas’s forearm tattoo, and that it was consistent with gang membership, as well as some (but not all) incidents in which Mr. Thomas was observed associating with known gang members. Detective Nasser was cross-examined, but only by counsel for the appellants’ co-accused, Mr. Thomas-Stewart.

[32] The jury charge included a general instruction on Detective Nasser’s expert opinion evidence, including that he had been qualified by training and experience to give an expert opinion regarding the nature and characteristics of street gangs, and cautioning the jury against the use of underlying information relied on by the expert, that was not in evidence. The trial judge provided a specific instruction on evidence of membership in a street gang that strongly warned against propensity reasoning. The trial judge reminded the jury that they heard evidence about the nature and characteristics of street gangs to understand the evidence in relation to criminal organization offences and to understand how gangs work and what their purpose is, in order to place the evidence in context. On each occasion that the trial referred to such evidence, he reminded the jury of the importance of not using the evidence improperly. There was no objection to these instructions.

C. ISSUES

[33] The appellants raise two issues on their conviction appeals:

1. Did the trial judge err by allowing the Crown to tender a gang expert who was both unnecessary and biased?

2. Did the trial judge err by admitting the gang expert evidence after a material change in circumstances?

[34] Deference is owed to a trial judge’s decision on admitting expert evidence absent an error in principle, a material apprehension of evidence or an unreasonable conclusion: R. v. Mills, 2019 ONCA 940, 151 O.R. (3d) 138, at para. 47 ; R. v. McManus, 2017 ONCA 188, 353 C.C.C. (3d) 493, at para. 68 . It is only where such an error is demonstrated that this court can interfere. In other words, the role of this court is not to take a fresh look at the admissibility of the expert evidence, and to arrive at its own conclusion.

[35] The appellants acknowledge that the trial judge identified the proper criteria and purported to apply the correct framework in determining the admissibility and scope of Detective Nasser’s opinion evidence when he made his initial ruling. They argue however that he erred in the application of the Mohan framework. Essentially, they contend that the trial judge erred in concluding – both at the initial stage and in weighing the probative value against the prejudicial effect of Detective Nasser’s evidence – that the expert evidence was necessary and impartial.

[36] The appellants also contend that the trial judge, in refusing to reopen his ruling in the light of certain admissions they were prepared to make, erred in principle by failing to find a material change in circumstances. I will address these arguments in turn.

D. DISCUSSION

(1) The applicable framework

[37] I begin by referring to the framework for the determination of admissibility of expert opinion evidence, including expert evidence about gangs. It is important to keep certain general principles in mind.

[38] Trial judges have the responsibility to act as “gatekeepers” in deciding whether to admit any expert evidence, in determining its scope and in ensuring that the expert evidence remains within its proper bounds at trial. Depending on how the trial unfolds, an admissibility ruling may need to be revisited. In jury trials, the judge will need to provide appropriate instructions so that the jury understands the limits on the permitted uses of the expert evidence: Mohan , at p. 24.

[39] The Mohan framework involves a two-step approach to determining the admissibility of expert evidence. At the first, or threshold, step, the court considers the four criteria of (1) whether the expert is properly qualified; (2) whether the evidence is affected by an exclusionary rule (other than the opinion rule itself); (3) whether the evidence is logically relevant to issues in the proceeding; and, (4) whether the expert evidence is necessary. The second, or “gatekeeper” stage requires the judge to balance the potential risks and benefits of admitting the evidence: White Burgess Langille Inman v. Abbott and Haliburton Co., [2015] 2 S.C.R. 182, at paras. 19 , 22-24; R. v. Sekhon, [2014] 1 S.C.R. 272, at paras. 43-44 , 46-47; R. v. J.(J.-L.), [2000] 2 S.C.R. 600, at para. 28 .

[40] Ontario courts are frequently called upon to apply the Mohan criteria to determine the admissibility and scope of expert evidence concerning gangs. As this court noted in R. v. Phan, 2020 ONCA 298, 387 C.C.C. (3d) 383, at para. 91 , the case law is replete with the admission of gang evidence for the purpose of providing context or narrative, to establish animus or motive, to establish the accused’s state of mind or intention, or for other purposes.

[41] At the same time, the cases recognize the risks associated with the admission of expert evidence concerning gangs. The primary danger arising from the admission of any opinion evidence is that the jurors’ function as fact-finders might be usurped by that of the witness: R. v. D.(D.), [2000] 2 S.C.R. 275, at para. 53 . A particular risk of expert evidence concerning gangs is the potential for “bad character” propensity reasoning. Bad character evidence itself is presumptively inadmissible unless the Crown can demonstrate that it is relevant to an issue in the case, and its probative value outweighs its prejudicial effects. The evidence is inadmissible if it serves only to show that an accused is the type of person likely to have committed the offence: R. v. B. (F.F.), [1993] 1 S.C.R. 697, at pp. 699, 731; [Phan], at paras. 90-91 ; R. v. G. (S.G.), [1997] 2 S.C.R. 716, at para. 65 .

[42] Trial judges decide on the need for expert evidence and weigh the probative value of the evidence against its prejudicial effect in the context of the live issues at trial, with the advantage of hearing the evidence in issue, observing the jury and being able to appreciate the dynamics of the particular trial: [D.(D.)], at paras. 12-13 . Ultimately the admissibility of any expert opinion evidence is highly case-specific: R. v. Gager, 2020 ONCA 274, at para. 27 , leave to appeal to S.C.C. refused, 39477 (April 22, 2021).

(2) The initial admissibility ruling: Did the trial judge err in admitting evidence that was unnecessary and biased?

(a) Necessity

[43] The appellants assert that the trial judge erred in concluding that the Mohan criterion of “necessity” was met in this case. They make two arguments. First, they say that Mr. Haye’s narrative and the issues in this case were not complicated or technical, such that the jury needed expert evidence to understand the context or motive for the alleged offence. It was obvious that the appellants and Mr. Haye were all members of a particular gang, and there was no need for an expert to explain to a jury why a street gang would want its gun back. Second, they argue that Detective Nasser’s evidence was made redundant by Mr. Haye’s testimony. Unlike many other cases where the victim was deceased or unavailable, and expert evidence was needed to “fill gaps in the evidence”, Mr. Haye could testify about the existence of the gang, gang membership and culture.

[44] The Crown contends that the trial judge did not err in determining that the expert evidence was necessary. There were many aspects of the evidence that fell outside the common knowledge of the jury, and outside Mr. Haye’s evidence. Mr. Haye’s testimony would not address whether the alleged acts were committed for the benefit of IDS, and whether IDS was a criminal organization. Moreover, Detective Nasser’s evidence provided the necessary factual context for the jury to be able to evaluate Mr. Haye’s narrative. The Crown argues that the evidence was essential to the jury’s ability to consider Mr. Haye’s account in the proper context and to fairly assess whether the attack on him occurred for the benefit of a gang.

[45] To meet the Mohan criterion of necessity, the question is whether the expert will provide information which is likely outside the ordinary experience and knowledge of the trier of fact: [D.(D.)], at para. 21 . “The subject-matter of the inquiry must be such that ordinary people are unlikely to form a correct judgment about it, if unassisted by persons with special knowledge”: R. v. Johnson, 2019 ONCA 145, 145 O.R. (3d) 453, at paras. 53 , 66. Expert evidence is not necessary if triers of fact can form their own conclusions without help because to do otherwise risks abdicating the role of deciding the facts to the expert: [Sekhon], at paras. 45, 49 . “Necessity” means that the evidence must be more than merely “helpful”, but necessity need not be judged “by too strict a standard”: Mohan , at p. 23.

[46] The trial judge adverted to these relevant principles in his reasons for admitting and setting the parameters for the expert evidence in this case. He concluded that the opinion evidence of Detective Nasser was necessary in the sense the evidence spoke to matters that were beyond the ordinary experience of the jury, and he rejected the assertion that the Crown should have to rely on Mr. Haye, who was an admitted gang member, to provide such evidence.

[47] I see no error in the trial judge’s conclusion that the expert evidence of Detective Nasser, as limited in scope by his ruling, was necessary, or in his conclusion that the fact that Mr. Haye would be testifying did not obviate the need for the evidence.

[48] First, I reject the contention that the matters to which the evidence was addressed were within the ordinary scope of understanding or experience of the jury. The offences were said to have been for the benefit of a criminal organization. It would have been wrong for the jury to rely on their own beliefs based on anecdotal experience and popular media about gang ideology and membership. Detective Nasser’s depth of knowledge and the fact that he was qualified as an expert to provide opinion evidence were readily acknowledged by the defence. The various matters about which he was permitted to testify – including the methods gang members used to identify themselves as members, the characteristics consistent with gang membership such as close associations with a known gang member, jewellery and tattoos, gang ideology, including discipline and the use of violence – were without question “outside the ordinary experience and knowledge of the [jury as] trier of fact”. The determination of what matters fall within the normal experience of jurors falls squarely within the trial judge’s domain: R. v. Boswell, 2011 ONCA 382, 277 C.C.C. (3d) 156, at para. 29 .

[49] I see no error in the trial judge’s conclusion that the jury needed the expert evidence as part of its assessment of whether the offences were committed for the benefit of a criminal organization, and to understand the context of what happened. While the necessity of expert evidence is case-specific, in several cases trial judges have accepted that the jury required expert evidence about aspects of gang culture that are not widely known, in order to understand the context in which the central events took place: see e.g. [Mills], at para. 24 ; R. v. Mohamed, Islow and Miller, 2020 ONSC 5074, at paras. 44-51 ; R. v. Gager, 2012 ONSC 388, at paras. 160-161 , aff’d 2020 ONCA 274; R. v. Monney, 2017 ONSC 250, at paras. 51-52 ; R. v. Sappleton, 2010 ONSC 5704, at paras. 157-158 ; R. v. Sandham, 2009 ONSC 59150 (Ont. Sup. Ct.), at paras. 15-17 .

[50] In its decision in [Phan] this court endorsed the following statement of Nordheimer J., as he then was, in R. v. Skeete, 2012 ONSC 737, at para. 15 , aff’d 2017 ONCA 926, 357 C.C.C. (3d) 159, leave to appeal refused, [2018] S.C.C.A. No. 508:

It remains the fact that a “criminal trial is, after all, about the search for truth”. A jury ought to be provided with information that will allow them to put the central facts into context including the nature of the relationships between persons connected to the events that might not otherwise be obvious. Jurors should not be placed in a situation where they are attempting to perform their truth seeking function in what is effectively either a factual vacuum or an artificial one.

This statement applies to the present case. Although the appellants are correct in saying that the core issue was credibility – whether Mr. Haye’s evidence about what occurred would be believed – the jury required information about how the gang operated, the motivations of gang members, and their internal discipline, to put his account into context.

[51] Second, I disagree with the contention that the proposed expert evidence ought to have been excluded as unnecessary because Mr. Haye, who was a member of IDS, was testifying and could provide the required evidence. Coupled with this is the argument that the expert evidence was unnecessary because it would serve only to unfairly bolster Mr. Haye’s evidence.

[52] Given the scope and limitations of Mr. Haye’s evidence, the trial judge properly rejected the argument that Detective Nasser’s evidence was unnecessary because Mr. Haye would provide all of the evidence needed to show that IDS was a street gang and that the accused were members of it. Mr. Haye had provided a police statement that was admitted as part of his evidence in chief on the Crown’s motion, after a voir dire pursuant to s. 715.1 of the Criminal Code . He was acknowledged by everyone at trial to be a difficult witness – he was at times defiant or unresponsive. He was a Vetrovec witness whose account of the events had changed over time. The trial judge’s conclusion that Mr. Haye’s testimony would not obviate the need for Detective Nasser’s evidence was informed by his understanding of the issues at trial, and his observations of Mr. Haye in the police interview that was the subject of the s. 715.1 application. He concluded:

Without the expert evidence, the jury will be left solely with the evidence of Dontay Haye. Dontay Haye may or may not give evidence regarding the use of violence by gangs to enforce discipline and communicate a message of obedience to the gang hierarchy.

Furthermore, Mr. Haye’s evidence is problematic, to say the least. Mr. Haye’s credibility will undoubtedly be subject to sustained assault in all respects. Without the context provided by the expert evidence, the jury will be left with his version of how gangs operate. The jury may well be left to puzzle over the purpose of an attempt to kidnap and beat Mr. Haye without context. The expert evidence will assist in evaluating his credibility (or lack of credibility).

[53] The trial judge’s assessment of the limits of Mr. Haye’s evidence was borne out at trial. Mr. Haye testified that he and the appellants and their co-accused were gang members. But he was unwilling to answer questions about IDS and how it operated. More importantly, his evidence did not provide the necessary context for the evaluation of the narrative.

[54] Contrary to the argument advanced on appeal, the fact that Mr. Haye testified at trial did not preclude the Crown from calling expert evidence that was otherwise admissible. Expert evidence respecting gangs can be relevant to understanding the context of the events and is not admissible only in cases where the victim is deceased or no gang member is testifying: see e.g. [Sandham], at paras. 18-19 ; [Abbey], at para. 4 .

[55] In [Boswell] a similar argument was made and rejected – that expert evidence about a code of silence that may have caused a community member to lie to the police ought not to have been admitted because the same evidence was available from the alleged victim, Sharp. This court observed that while Sharp testified about the code and its effect on his conduct, his credibility was very much in issue, he was vigorously attacked by the defence, and his evidence was the subject of a strong Vetrovec warning. The court stated, “In these circumstances it cannot be said that expert evidence regarding the general existence of a code of silence and its nature was unnecessary because the evidence was otherwise available through Sharp”: at para. 31. In the present case, the trial judge made a similar evaluation in rejecting the argument that the evidence was unnecessary because it could have been provided by Mr. Haye.

[56] Nor, as I will explain, do I accept the appellants’ argument that because the expert evidence provided context to understand the narrative that was provided mainly though the evidence of Mr. Haye, the expert evidence served only to unfairly bolster Mr. Haye’s credibility.

[57] The determination of a witness’s credibility and reliability is for the trier of fact and is not the proper subject of expert opinion. An expert opinion cannot be introduced if the purpose is solely to bolster a witness’s credibility (i.e.: oath-helping). “Credibility is a notoriously difficult problem, and the expert’s opinion may be all too readily accepted by a frustrated jury as a convenient basis upon which to resolve its difficulties”: R. v. Marquard, [1993] 4 S.C.R. 223, at p. 248.

[58] Detective Nasser was not invited to express an opinion about the credibility of Mr. Haye, or about the events that were said to have occurred. And, while the credibility of Mr. Haye was assessed by the jury in the context of the evidence as a whole, including the opinion evidence of Detective Nasser, the purpose of Detective Nasser’s evidence was not to convey to the jury a belief that Mr. Haye was truthful. Rather, the purpose was to ensure that the jury evaluated all of the evidence in its proper context, to determine whether the alleged offences occurred, and if so, whether they were for the benefit of a criminal organization. While that context helped the jury to evaluate the credibility of Mr. Haye’s account, evidence that may support the credibility of a witness does not, by reason of that incidental effect, offend the rule against oath-helping: R. v. Llorenz, 2000 ONCA 5745, 145 C.C.C. (3d) 535 (Ont. C.A.), at para. 28 . See also R. v. K.A., 1999 ONCA 3793, 45 O.R. (3d) 641 (C.A.), at p. 678 and Sappleton , at para. 164.

[59] In his final instructions, the trial judge explained to the jury the use they could make of the expert evidence, and he cautioned them against its misuse. He told the jury that it was necessary that they hear this evidence “in relation to the offences relating to a criminal organization” and for “an understanding of how the gang works, and what its purpose was”. Rather than inviting the jury to rely on the evidence to bolster Mr. Haye’s credibility, he instructed the jury that “[this evidence] will help you to place the evidence in context, including why you must approach Dontay Haye’s evidence with caution ”.

[60] For these reasons, I would not give effect to the appellants’ arguments respecting the necessity of the expert evidence.

(b) Bias and partiality

[61] The appellants argue on appeal that the trial judge erred in refusing to exclude Detective Nasser’s evidence because of serious concerns about his ability to be independent, impartial and unbiased. They rely on two incidents that arose in the context of the voir dire . First, Detective Nasser failed to disclose to the defence that he had spoken with a gang member and overheard the conversations of several gang members who attended court one day. This information only came out the next day when Detective Nasser was testifying, and Crown counsel asked about the encounter. According to the appellants, this information was significant as it would later form part of the trial judge’s ruling allowing Mr. Haye to testify via CCTV. Second, Detective Nasser was unwilling to answer questions from defence counsel outside of court. The appellants also point to Detective Nasser’s CV, where, in listing his experience as a gang expert, under one trial where he had been previously qualified, he noted that both accused were convicted. This implies that Detective Nasser was proud of the fact that there had been a conviction in a case where he had testified for the Crown, and demonstrated that he was not impartial.

[62] In their appeal, the appellants assert that Detective Nasser’s evidence did not meet the initial stage of the Mohan test because these incidents were inconsistent with the expert’s duty to the court to be an independent witness. They also argue that the expert’s bias was not considered by the trial judge at the cost/benefit stage of determining admissibility.

[63] The Crown contends that the three concerns raised by the appellant did not undermine Detective Nasser’s impartiality to the point where his evidence ought to have been excluded. First, the encounter with gang members that Detective Nasser failed to disclose to the defence had no bearing on his report and the trial judge had determined that the appropriate remedy would be for Detective Nasser to disclose his notes, if any, before cross-examination by the defence. Second, Detective Nasser had explained that his reluctance to answer a question from defence outside the court was because of his prior experience with counsel using the opportunity to decide whether to use the question in their cross-examination and that he felt it was most fair to answer the question in court. The trial judge addressed this in his reasons and concluded that the evidence was still reliable. Third, the CV entry is a factual statement of the outcome of that trial and Detective Nasser had listed that an accused had been acquitted in a different entry. The Crown also points out that defence counsel’s submissions at trial concerning bias and partiality were quite different from those now raised on appeal.

[64] Impartiality and lack of bias are part of the threshold requirements for admissibility, in determining whether an expert is properly qualified. Exclusion at the threshold stage should occur only in very clear cases, where the proposed expert is unable or unwilling to provide the court with fair, objective and non‑partisan evidence. Alleged partiality and bias are considered again at the gatekeeping stage in weighing probative value (which includes relevance, necessity, reliability and absence of bias) against the dangers associated with expert evidence. Context is important; both the extent of the expert’s alleged bias and the nature of the proposed evidence are relevant: [White Burgess], at paras. 49, 53-54; R. v. Natsis, 2018 ONCA 425, 140 O.R. (3d) 721, at para. 11 ; [Mills], at para. 45 .

[65] While the issue of bias and partiality was raised by defence counsel at trial, as the Crown points out, defence counsel’s arguments differed from what is advanced on appeal. At trial, defence counsel did not raise concerns about Detective Nasser’s CV, take issue with his failure to disclose his encounter with gang members after this matter was raised and remedied by the trial judge, nor suggest his evidence was inadmissible at the first stage of Mohan on the basis that he was unwilling or unable to meet his obligations as an impartial and unbiased expert. Rather, in making submissions about the probative value versus prejudicial effect of the evidence, defence counsel asserted that Detective Nasser was not a disinterested expert because (1) he did not wish to engage with defence counsel on a particular issue outside the courtroom setting; and (2) his background work into certain incidents of gang association or indicia of gang membership involving the accused did not go far enough. In addressing these arguments, the trial judge concluded:

It is true that some of [Detective] Nasser’s background work could have gone further. It is also true that he should have been prepared to answer counsel’s questions outside of court. It is usual that police officers, and not only experts, do that. I found it troubling that he did not do so. Nonetheless, I am satisfied that his evidence meets the test for threshold reliability. The issues raised by counsel go to the weight to be given to his opinion by the jury.

[66] Leaving aside the fact that this argument was not raised at first instance, there is no error in the trial judge’s refusal to exclude Detective Nasser’s expert evidence at the threshold stage due to bias or partiality. The concerns raised by the appellants did not demonstrate “a clear unwillingness or inability” for Detective Nasser to meet his obligations as an expert witness. Moreover, the appellants accepted that Detective Nasser was a properly qualified expert.

[67] The appellants submitted in argument on the appeal that, contrary to what I have expressed above, the trial judge considered partiality only at the first stage of Mohan , and not at the second stage of weighing prejudice. They point to the statement in his reasons that he was “satisfied that [the expert’s] evidence meets the test for threshold reliability. The issues raised by counsel go to the weight to be given to his opinion by the jury.”

[68] I disagree. Although, in this passage, the trial judge referred to threshold reliability, it is apparent from the structure of his reasons (where this paragraph followed a discussion of the principles applicable to the cost/benefit analysis), as well as the submissions of counsel at trial, that he did what he was invited to do. He addressed the argument that the incidents of alleged partiality affected the probative value of Detective Nasser’s evidence. He had already determined that the evidence met the threshold tests for relevance and necessity and the two other Mohan criteria had been conceded, including that Detective Nasser was a “qualified expert”. The trial judge was concerned by Detective Nasser’s refusal to engage with defence counsel outside the court room and the extent of his background work, but he concluded that this did not reduce the probative value in the cost/benefit analysis such that his evidence should be excluded. The trial judge properly observed that the issues raised by the defence could be addressed in the expert’s cross-examination.

[69] The trial judge did not err in his approach to the appellants’ arguments about bias and partiality. There was no realistic concern that the expert was unable to comply with the duty to provide independent, impartial and unbiased evidence. Nor did the trial judge err in his assessment of these factors as part of the cost/benefit analysis. As in [Mills], at para. 68 , the trial judge heard the expert testify in the voir dire , had his report, and was therefore “in a good position to determine whether [the expert] showed partiality, a lack of independence, and/or bias”.

(3) Did the trial judge err in his cost/benefit assessment of the proposed expert evidence?

[70] The appellants argue that, even if Detective Nasser’s evidence was necessary and reliable, the prejudicial effect of the evidence outweighed its probative value. The probative value of the expert evidence was low because Mr. Haye was available to testify and did testify about gang-related information. The prejudicial effect, by contrast, was significant because Detective Nasser’s evidence was bad character evidence. The evidence regarding gang culture portrayed a lifestyle of crime and violence, and by implication painted the accused as “stereotypical thugs”.

[71] Similar to their argument at the initial stage of the admissibility test, concerning necessity, the appellants contend that the effect of introducing this evidence was simply to bolster Mr. Haye’s credibility “by giving the jury the impression that Mr. Haye was telling the truth because [the three accused] were gang members and gang members are bad people.” The appellants say that Mr. Haye’s evidence was enhanced by “dragging the characters of the appellants through the mud”. They say this was particularly important with respect to the charge of attempted murder: while the allegations as a whole were supported by video evidence, the only evidence with respect to the attempted murder, that Mr. Oppong told Mr. Haye he would kill him if he did not give up the gun, came from Mr. Haye himself. The appellants argue that the jury undoubtedly would have been influenced by the expert evidence in assessing the credibility of this allegation.

[72] The Crown submits that there was no error in the trial judge’s conclusion that the probative value of the evidence outweighed its prejudicial effect. Detective Nasser provided limited opinion evidence and limited information about the appellants. The appellants admitted that they were members of IDS. The jury was also properly instructed on the use of this evidence.

[73] The weighing of the costs and benefits of proposed expert evidence is entitled to deference. Doherty J.A. in [Abbey], noted that the gatekeeper phase is more difficult and subtle, involves the exercise of judicial discretion and is case‑specific. He observed, at para. 79, that “[d]ifferent trial judges, properly applying the relevant principles in the exercise of their discretion, could in some situations come to different conclusions on admissibility”.

[74] There was no reversible error in the trial judge’s assessment of the costs and benefits of receiving the expert evidence.

[75] First, as I already have observed, the trial judge considered the allegations of partiality as part of his assessment of the reliability of the evidence, in weighing its probative value against its prejudicial effect. Reliability includes consideration of the extent to which the expert is shown to be impartial and objective: [Abbey], at para. 87 ; [Mills], at para. 45 .

[76] Second, and as I have explained, there was significant probative value to the expert evidence in helping the jury to understand the context of what occurred. The central issue for the jury to determine was whether Mr. Haye was telling the truth about what happened. He was thoroughly cross-examined. It was brought home to the jury that it was their responsibility, as the finders of fact, to determine Mr. Haye’s credibility and reliability. The role of the expert evidence was to help them to understand the context in which Mr. Haye and the three accused were operating.

[77] Third, and contrary to Mr. Oppong’s submissions on appeal, there is no indication that the jury would have improperly used the expert evidence to reason that, as a member of a gang he was a bad person, and that accordingly Mr. Haye must have been telling the truth. Mr. Haye himself was an admitted gang member who sometimes carried a gun and sold drugs. The jury was specifically cautioned, repeatedly, not to engage in propensity reasoning. They were also cautioned about the dangers of relying on Mr. Haye’s evidence, and instructed that the expert evidence was to help them to place the evidence in context, including why they must approach Mr. Haye’s evidence with caution. Jurors are presumed to understand and follow the instructions they are given: R. v. Bains, 2015 ONCA 677, 127 O.R. (3d) 545, at paras. 61 , 98, leave to appeal refused, [2015] S.C.C.A. No. 478. Finally, the jury clearly did not accept Mr. Haye’s evidence without reservation: they were not satisfied that Mr. Oppong threatened to kill Mr. Haye, as they found him not guilty of attempted murder.

[78] For these reasons I would dismiss this ground of appeal.

(4) Did the trial judge err in refusing to reconsider his ruling based on a material change in circumstances?

[79] The appellants assert that the fact that they were prepared to admit that IDS was a gang and that they were members of IDS constituted a material change in circumstances. They submit that the Crown opposed the application and refused to consent to the admission, which was an improper attempt to keep an issue artificially alive to introduce prejudicial evidence. Because the appellants were willing to admit “almost all” of what the expert would testify about, the prejudicial effect of the evidence would outweigh its probative value, which was “almost nil”. They contend that the trial judge erred in concluding that there was no material change in circumstances, and then refusing to reconsider his ruling. The appellants also asserted in oral argument, that the trial judge ought to have required the Crown to work with defence counsel to come up with a set of agreed facts, and then to consider whether the expert evidence was admissible in light of the new evidentiary framework.

[80] The Crown submits that there was no error in the trial judge’s ruling on the application to re-open the ruling. While trial judges can revisit evidentiary rulings, the defence had the onus of establishing a material change in circumstances. The Crown asserts that the trial judge did not err in concluding that the appellants’ proposed admissions did not constitute a material change in circumstances, as those admissions would not assist the jury in understanding the context of Mr. Haye’s evidence. Further, there would be difficulties in managing a trial where one of the accused would not make the same admissions as the other two, and the Crown was not willing to use an agreed statement of facts as the necessary context cannot be provided to the jury in a list of facts.

[81] The point of departure is that a defendant’s admission requires the acceptance of the Crown: Criminal Code , s. 655; Castellani v. R., [1970] S.C.R. 310. That said, while a trial judge cannot require the Crown to accept certain admissions, the Crown “should not be allowed to gain entry for prejudicial evidence by refusing to accept the admissions [an accused is prepared to make]”: R. v. Proctor, 1992 MBCA 2763, 69 C.C.C. (3d) 436 (Man. C.A.).

[82] The issue here was not whether or not the Crown was prepared to accept the admissions the accused were willing to make, or whether the trial judge had the ability to revisit his ruling in the light of admissions that were proposed , even if not yet accepted by the Crown. Rather, the focus was on the extent of the proposed admissions, and whether they would affect the cost/benefit analysis in relation to the expert evidence.

[83] The appellants were prepared to admit that IDS existed, that they were members and that if the jury found that the acts were committed, that it was at the behest of a criminal organization. The third accused, Mr. Thomas-Stewart, however was only prepared to admit that IDS is a street gang, that association with other members is one of the characteristics of a gang member, and his associations on four separate dates (that did not include the date of the alleged offences). He was not prepared to admit that he was a member of IDS or that, if the allegations of his conduct were proven, it was for the benefit of a criminal organization.

[84] The appellants assert that the trial judge was wrong to conclude that there was no material change in circumstances in this case. In oral argument, the appellants also argued that the trial judge did not even embark on an analysis of the effect of the proposed admissions because he concluded that there was no change in circumstances.

[85] I disagree. The trial judge accepted that there was a change in circumstances, but he concluded that it was not material . He accepted that he had the ability to revisit his ruling, and he heard argument on the issue. The trial judge properly observed that, in order for the change of circumstances to be material, it must “alter the balance between the prejudicial effect and probative value” of the evidence. The defence argument was that the proposed admissions would render the expert evidence much less probative because they were more extensive than the expert evidence. The trial judge properly rejected this submission. While the proposed admissions would obviate the need for certain evidence in relation to the appellants’ membership in IDS, the trial judge observed that “[t]he key point about [Detective] Nasser’s evidence is that it is supposed to help the jury understand the background. The proposed admissions do nothing to advance the jury’s understanding without context”. In other words, the trial judge concluded that the changed circumstances – the proposed admissions by the accused – were not material because they did not alter the cost/benefit analysis in relation to the expert evidence.

[86] Mr. Thomas’s counsel argued before the trial judge that the Crown was attempting to keep the issue of how gangs operate artificially alive in order to bolster Haye’s credibility. Rejecting the submission of Mr. Thomas’s counsel that the expert evidence was simply an attempt at oath-helping, the trial judge noted: “As I stated in my original ruling, the purpose of the expert evidence was to allow the jury to understand his evidence given the circumstances of a gang-related offence”.

[87] As I have already explained, permitting the expert to testify in order to provide context for the assessment of the narrative, including the account provided by Mr. Haye, was a proper purpose for the admission of the expert evidence in this case. The trial judge had already made this determination. The jury was not invited to use the evidence to bolster Mr. Haye’s credibility, nor was there a reasonable prospect that they would misuse the evidence.

[88] There were arguments at trial about the scope of Detective Nasser’s evidence in light of the proposed admissions, which were not renewed on appeal. As I have already noted, in the course of Detective Nasser’s evidence, counsel for the appellants conceded their clients’ membership in IDS which resulted in the Crown refraining from eliciting certain evidence from Detective Nasser regarding their associations.

[89] Finally, on appeal the appellants contend that the trial judge should have required the parties to attempt to agree to facts about general characteristics of gangs, that could have been entered as an agreed statement of facts. Counsel did not suggest how that could have been done in this case – that is, what facts could reasonably have been admitted. The record suggests that there may have been some discussions between defence counsel and the Crown that had not borne fruit, and that Mr. Oppong’s counsel suggested in the application to revisit the expert evidence ruling that this could be done. There had already been a lengthy voir dire to determine the admissibility and scope of the expert’s evidence in this case. There is no indication that anyone had proposed to the trial judge, in advance of his initial ruling, that the expert evidence could or should have been introduced through an agreed statement of facts. This submission, made late in the day by one defence counsel, attracted the appropriate response from the trial judge. He observed that there was no agreed statement of facts and that he had no power to compel any party to make a concession it was not otherwise prepared to make.

[90] For these reasons I see no error in the trial judge’s refusal to exclude Detective Nasser’s expert evidence on the defence motion to revisit his ruling.

III THE SENTENCE APPEAL

[91] Mr. Oppong appeals his sentence. He says that the trial judge erred in making a finding of fact that was unsupported by the evidence – that he was the leader of the IDS. The trial judge stated that the most important aggravating factors for Mr. Oppong included his leadership of IDS. Mr. Oppong submits that there was no evidence to support this conclusion, and that this error led the trial judge to impose a longer sentence on the appellant than on his two co-accused.

[92] The Crown argues that the trial judge’s conclusion that Mr. Oppong had “a leadership role” in the gang was supported by the evidence, and that in any event the trial judge explained why he should receive a greater sentence than his co‑accused, and imposed a sentence that was fit in all the circumstances.

[93] Although I would grant leave to appeal sentence, I would dismiss the sentence appeal.

[94] First, there was evidence to support the trial judge’s reference to Mr. Oppong’s “leadership role” in the gang. He was described by Mr. Haye as “one of the older heads” of the gang. Mr. Oppong is correct in noting that there was evidence about the leadership, including Detective Nasser’s list of the ten leaders (which did not include Mr. Oppong). The trial judge did not conclude however that Mr. Oppong was “the leader” of IDS, only that he had a “leadership role”.

[95] More importantly, however, it was open to the trial judge to find, as he did, that Mr. Oppong took the lead role in the kidnapping of Mr. Haye, which Mr. Oppong had admitted was for the benefit of IDS. In fixing the appropriate sentences, the trial judge considered the specific role each of the accused had played in the attack on Mr. Haye. He concluded that Mr. Oppong had played “the lead role” in the kidnapping and was “enforcing the rules of the gang”. This was in contrast to his co-accused who had “secondary roles”.

[96] An appellate court can only interfere with a sentence when there is a demonstrated error of law or principle that had an impact on the sentence, or the sentence is demonstrably unfit: R. v. Friesen, [2020] 1 S.C.R. 424, 391 C.C.C. (3d) 309, at para. 26 . No error has been demonstrated. Mr. Oppong’s sentence was fit. There is no basis for appellate intervention.

IV DISPOSITION

[97] For these reasons I would dismiss the conviction appeals, and while I would grant leave to Mr. Oppong to appeal his sentence, I would dismiss his sentence appeal.

Released: May 25, 2021 “P.R.”

“K. van Rensburg J.A.”

“I agree. Paul Rouleau J.A.”

“I agree. B.W. Miller J.A.”

[1] In his factum, Mr. Oppong also challenged the order under s. 743.6(1.2) of the Criminal Code requiring him to serve one half of his sentence before he is eligible to apply for parole. This issue, which is fully answered by the Crown’s factum, was not pursued in oral argument, and will not be addressed in these reasons.

[2] Detective Nasser was referred to in the reasons below as “Sergeant Nasser”, the position he held when he prepared his expert report.