COURT OF APPEAL FOR ONTARIO
CITATION: Mousaly (Re), 2026 ONCA 605
DATE: 20260826
DOCKET: M57308 (COA-26-CR-0101)
Dawe J.A. (Motion Judge)
IN THE MATTER OF: James Mousaly
AN APPEAL UNDER PART XX.1 OF THE CRIMINAL CODE, R.S.C. 1985, c. C‑46
Amy Rose and Amy Alyea, for the appellant Attorney General of Ontario
Erin Dann, for the respondent James Mousaly
Jessica Szabo and Kyle Dow, for the respondent Person in Charge, Ontario Shores Centre for Mental Health Sciences
Lisa Matthews and Kelvin Ramchand, for the proposed intervener Director of Public Prosecutions
Heard: August 17, 2026
REASONS FOR DECISION
[1] The Attorney General of Ontario is appealing the decision of the Ontario Review Board (the “Board”) granting an absolute discharge to the respondent James Mousaly, who was previously found not criminally responsible on account of mental disorder: Mousaly (Re), 2026 CanLII 2108 (Ont. R.B.). The federal Director of Public Prosecutions (“DPP”) seeks leave to intervene in the appeal, which is scheduled to be heard on October 22, 2026. I have been assigned to decide the intervention application.
[2] By way of background, Mr. Mousaly was previously employed as a Nuclear Operator at one of Ontario Power Generation’s nuclear power plants. In January 2025, he live-streamed a video on YouTube in which he disclosed sensitive information about potential nuclear power plant vulnerabilities, and offered to provide more information to foreign entities or terrorist groups. The video was only posted online very briefly, and only a portion of it was preserved. It was an agreed fact that it was unknown how many people watched the video before it was taken down.
[3] Mr. Mousaly was charged with committing an offence under s. 16(1) of what is now the Foreign Interference and Security of Information Act,R.S.C. 1985, c. O-5.[1] The DPP was the prosecuting Crown agency. On October 9, 2025, Mr. Mousaly was found not criminally responsible, on a joint submission by the parties. He was detained at the Ontario Shores Centre for Mental Health Sciences (the “Hospital”), and referred to the Board for a disposition hearing.
[4] By agreement, the Crown was represented at the Board hearing by the Attorney General of Ontario rather than by the DPP: see Criminal Code,R.S.C. 1985, c. C-46, ss. 672.1(2) and 672.5(3). Crown counsel took the position that Mr. Mousaly remained a significant threat to the safety of the public. Mr. Mousaly and the Hospital both took the position that he was not a significant threat to the safety of the public, and thus should be granted an absolute discharge: Criminal Code,s. 672.54(a). A majority of the Board was not satisfied that the significant risk threshold was met, and granted Mr. Mousaly an absolute discharge. The lay member of the panel dissented. He would have found that the threshold was met, and would have granted Mr. Mousaly a conditional discharge.
[5] The provincial Crown is appealing the Board’s decision to this court, and the DPP seeks to intervene in the appeal. The provincial Crown supports the DPP’s intervention application. Mr. Mousaly and the Hospital both oppose it.
[6] The DPP has submitted a draft of the factum it proposes to file in the appeal if it is granted leave to intervene. Somewhat unusually, because of the expedited timetable for hearing Part XX.1 Criminal Code appeals under Part VI of the Criminal Appeal Rules,[2] the parties to the appeal have not yet filed their own factums on the appeal, although Mr. Mousaly and the Hospital both filed factums on this motion.
[7] As Fairburn A.C.J.O. explained in R. v. Doering,2021 ONCA 924, at paras. 9-10:
Multiple criteria inform whether to grant leave to intervene in an appeal as a friend of the court, including the general nature of the case to be heard, the issues that arise in the case, and the contribution that the intervener can make to those issues without doing an injustice to the parties.
While it is rare to permit an intervention in a criminal case unless a constitutional issue is raised, there is no rule against such interventions. It remains a question of whether the proposed intervener will make a useful contribution beyond that offered by the parties without causing an injustice to the parties. [Citations omitted.]
[8] There is no dispute that the DPP, as the Crown entity that prosecuted Mr. Mousaly, has a genuine interest in the subject matter of the appeal. There is also no dispute that the DPP has particular expertise in the two areas of law it identifies in its supporting motion record: (i) the prosecution of national security offences; and (ii) the protection of “sensitive information” as defined in s. 38 of the Canada Evidence Act, R.S.C. 1985, c. C-5 (the “CEA”).
[9] The DPP argues that this legal expertise will enable it to make useful submissions about the application of the “significant threat to public safety” test in s. 672.54(a) of the Criminal Code,as interpreted by the Supreme Court of Canada in Winko v. British Columbia (Forensic Psychiatric Institute), 1999 CanLII 694 (SCC), [1999] 2 S.C.R. 625, in the particular context of national security offences.
[10] In my view, there are two main problems with the DPP’s argument. The first, and most serious, is that the draft factum it proposes to file on the appeal does not limit itself to making submissions about the underlying legal context. Indeed, its proposed submissions about national security offences and the s. 38 CEA regime are brief – just over two pages – and consist of little more than a summary of well-established legal principles. Nearly all of the DPP’s proposed factum is devoted instead to making arguments about why the Board majority was wrong to find, on the particular facts of this case, that Mr. Mousaly did not present a significant threat to public safety.
[11] Significantly, the DPP does not support these arguments by making any submissions about the proper legal interpretation of the “significant threat to public safety” test. Instead, its arguments focus on the specific facts of this case, and on errors it says were made by Dr. Wang, the forensic psychiatrist who wrote the Hospital Report and who testified at the Board hearing. As Mr. Mousaly points out, these latter arguments appear to largely track the submissions that were made by the provincial Crown at the Board hearing.
[12] Put simply, the DPP’s draft factum reads more like an appellant’s factum than a factum submitted by an intervener as a friend of the court. Indeed, the DPP’s draft factum takes an express position on how the appeal should be decided, urging the court to “endorse” the dissenting reasons of the lay Board member, who would have found that Mr. Mousaly presents a significant threat to public safety, and who would have imposed a conditional discharge. In other words, the DPP appears to be urging the court to set aside the Board’s factual finding, make its own contrary factual finding, and ultimately impose a different disposition. In contrast, in its notice of appeal the provincial Crown merely requests an order remitting the case for a new hearing before the Board.
[13] The second problem is that it is not apparent that the DPP’s expertise in national security law and s. 38 CEA national security privilege issues would assist the panel, having regard to what appear to be the live issues in the appeal.
[14] The underlying premise of the DPP’s arguments seems to be that Dr. Wang, and by extension the Board majority, failed to properly appreciate Mr. Mousaly’s future dangerousness because they did not grasp the seriousness of his index offence. According to the DPP:
Dr Wang found—due to the redactions to the trial record—that it was “not clear…that there was identifiable harm to anyone as a result of that video”: Re Mousaly, para 12. The ORB relied on Dr Wang’s opinion to find that Mr. Mousaly did not pose a serious risk to public safety. [Emphasis in original; footnotes omitted.]
[15] I note that the DPP’s submissions about Dr. Wang’s evidence are very similar to those made by Crown counsel at the Board hearing, as summarized at para. 104 of the majority’s reasons.
[16] In my view, the DPP’s characterization both of Dr. Wang’s evidence, and of the ratio of the Board majority’s decision, are not supported by the record. As summarized by the Board majority in their reasons, at para. 12:
In response to a question about the index offence, Dr. Wang testified that a lot of information about the index offence had been redacted so he didn’t know what was specifically disclosed by Mr. Mousaly. Dr. Wang testified that Mr. Mousaly understands that he is not supposed to talk about what he disclosed. Dr. Wang gave evidence that it was unclear to him, based on the information he has read as to what harm came as result of that disclosure by Mr. Mousaly. Dr. Wang testified that much of what Mr. Mousaly said during the video was concerning and sounded concerning to Dr. Wang and many other people when he mentioned terrorists and terrorist groups but it was not clear to Dr. Wang that there was identifiable harm to anyone as a result of that video.
[17] In essence, Dr. Wang appears to have explained, in response to a question, that he could not be sure that the index offence had caused “identifiable harm to anyone” because he did not know the specifics of the information that Mr. Mousaly had disclosed in his YouTube video, much of which had been redacted from the record that Dr. Wang had reviewed. (Indeed, since it was an agreed fact that the number of people who saw the video before it was taken offline was unknown, it is questionable whether Dr. Wang could have offered an opinion about whether the index offence had caused “identifiable harm to anyone” even if he had seen the unredacted video.)
[18] Importantly, Dr. Wang does not appear to have suggested that the index offence was not serious. Indeed, nobody at the Board hearing seems to have disputed the proposition that extremely serious harm could result if Mr. Mousaly were to commit a similar offence in the future.
[19] Even more importantly, this is an appeal from the Board majority’s disposition order, not a review of Dr. Wang’s opinion. The Board majority did not base its decision on this aspect of Dr. Wang’s evidence, nor did the Board majority suggest or imply that disclosing secret information about nuclear power plant vulnerabilities would not present a “significant threat to public safety”. Rather, the Board majority explained, at para. 127, that they had:
… considered the reasoning of the Ontario Court of Appeal in Ferguson (Re) 2010 ONCA 810 which followed Winko and which held that a very small risk of even a grave harm will not suffice and a very high risk of relatively trivial harm will also not meet the substantial harm threshold. The Board finds that the said reasoning in Winko and Ferguson applies to the herein matter. [Emphasis added.]
[20] The majority continued by stating, at para. 130:
The majority of the Board also considered the analysis of counsel for the hospital which posited that a series of seven factors … would all have to occur before any harm would result to any person, and concluded that the likelihood of all seven steps occurring was remote at best. As the case law so abundantly set out, even a small risk of a grave harm does not meet the significant threat threshold. The majority of the Board finds that this is such a case. [Emphasis added.]
[21] In my view, these passages make clear that the Board majority found that the “significant threat to public safety” test was not met because they found the likelihood of Mr. Mousaly committing a similar offence in the future to be small, not because they did not appreciate that such an offence, if committed, could cause grave harm to the public.
[22] I appreciate that it is not my task on this motion to decide the appeal. However, I am obliged to consider “the issues that arise in the case, and the contribution that the intervener can make to those issues without doing an injustice to the parties”: Doering,at para. 9 (emphasis added). In my view, the DPP’s proposed submissions are unlikely to significantly assist the panel that hears the appeal, because they are directed at matters that appear to be undisputed, and that are orthogonal to what I see as the live issues presented by this appeal.
[23] On the other side of the ledger, I agree with Mr. Mousaly that he will be prejudiced if he has to respond to what would effectively amount to submissions from two Crown appellants: see Doering, at para. 21.
[24] In Doering,Fairburn A.C.J.O. found that it was “problematic” that the proposed interveners’ factum “[did] not properly confine itself to the legal issues it purports to advance”: at para. 20. However, she went on to explain that this was “a problem that can be easily overcome” by circumscribing the scope of the proposed interveners’ argument in the order granting them leave to intervene: Doering, at para. 22.
[25] Counsel for the DPP submits that I should take a similar approach here.
[26] While I have no doubt that counsel for the DPP would abide by any order I make, I am not satisfied that the approach taken in Doeringcan be adopted here without causing prejudice to Mr. Mousaly. I reach this conclusion for five main reasons.
[27] First, the interveners’ proposed submissions in Doeringappear to have been mainly directed at “advancing legal issues that are properly the subject of intervention”, despite their written argument occasionally “crossing the line into the actual merits of the appeal”: Doering,at para. 22. In contrast, the DPP’s draft factum spends nearly all of its time on the wrong side of the foul line. If I were to disallow the portions of the draft factum that cross into impermissible territory, very little of the current draft would be left.
[28] Second, as I have already explained, even if the DPP were to file a revised factum that limited itself to addressing the legal issues on which it has acknowledged expertise, I am not persuaded that these submissions would assist the panel. To reiterate, none of the parties to this appeal seem to dispute the basic propositions that secrets about nuclear power plant vulnerabilities need to be closely guarded, and that disclosing these secrets is a very serious offence that could cause extremely grave harm to the public. The Board majority did not suggest otherwise. Rather, it found that Mr. Mousaly did not present a significant threat to public safety because the risk of his reoffending in a similar manner in the future was low, even though his reoffending could cause “grave harm”. The DPP has no particular expertise with respect to issues of risk assessment in the context of Part XX.1 Criminal Code proceedings.
[29] Third, this case is different from Doering in that it involves an intervention application by a Crown agency that seeks to support a Crown appellant, in an appeal where the respondent’s liberty interests are directly at stake. In my view, the fairness concerns are significantly elevated in this context.
[30] Fourth, considering the different procedural context in this case, I am not satisfied that a Doering-style order would not cause prejudice to Mr. Mousaly and the Hospital. In Doering,where several police groups sought to intervene in support of an appellant police officer, the respondent Crown already had the appellant’s factum and thus already knew how the issues on appeal were being framed. In contrast, because this appeal is being conducted under the compressed filing schedule that governs Part XX.1 Criminal Code appeals, the appellant provincial Crown’s factum does not have to be served and filed until mid-September. If I were to grant the DPP intervener status but make a direction that it must substantially revise its factum, Mr. Mousaly and the Hospital would find themselves having to respond to two new Crown factums in early or mid-September, and would have only a few weeks to prepare their responses.
[31] Fifth, I am not persuaded that denying the DPP intervener status will cause any substantial unfairness to the DPP, which I agree has an entirely legitimate interest in this appeal. Unlike the situation in Doering,the appellant provincial Crown has not yet filed its factum. If the DPP has submissions about the intersection between national security law and the Part XX.1 review process that it wishes to have put before the panel, it can communicate them to its provincial Crown colleagues, and they can include these submissions in their written argument. Having regard to what seem to be the live issues in the appeal, I am not persuaded that it is essential for the DPP to be separately represented by its own counsel for its position to be fairly presented to the panel.
[32] In the result, the DPP’s application for intervener status is dismissed. I would like to thank all counsel for their very helpful submissions.
“J. Dawe J.A.”
1Formerly the “Security of Information Act”.
2In most criminal and civil appeals, the appeal hearing is not scheduled until after the appellant has filed its factum. However, for Part XX.1 appeals the hearing date is scheduled first, and the appellant’s factum must be filed at least six weeks before the hearing: Criminal Appeal Rules, r. 70(6).