SCC: Ontario judge’s jury instructions not faulty in attempted murder by insulin trial

The SCC rejected the theory that the accused was aiding one of the alleged victims’ suicide

SCC: Ontario judge’s jury instructions not faulty in attempted murder by insulin trial
Elina Marinosyan
By Jessica Mach
Dec 05, 2025 / Share

An Ontario trial judge was right to give the jury in a murder trial instructions that did not account for the possibility that the accused, a nurse, had supplied insulin to one of her alleged victims to assist with the latter’s suicide, the Supreme Court of Canada ruled in a 6-3 decision on Friday.

The case involves three people – the nurse, known as B.F., her 19-month-old child, and her mother – who were found unconscious in an Ontario apartment in 2019 after being injected with large doses of insulin.

While each person survived, the child suffered permanent brain damage and irreparable damage to other organs. An Ontario trial court convicted B.F. of attempted murder of her mother and child, as well as aggravated assault of her child.

In a decision last year, however, the Ontario Court of Appeal set aside B.F.’s conviction for the attempted murder of her mother and ordered a new trial. The appellate court said that the trial judge erred by giving instructions to the jury that allowed it to convict B.F. of attempted murder based on actions that could instead be construed as her helping her mother commit suicide. While the latter is still a criminal offence, it is distinct – and proven through a different set of criteria – from attempted murder.

In its decision in R. v. B.F., a majority for the Supreme Court rejected this line of reasoning.

“In my view, the Court of Appeal unnecessarily complicated this matter by holding that the jury needed to be instructed on the distinction between attempted murder under s. 239 of the Criminal Code and aiding suicide under s. 241(1)(b),” SCC Justice Michelle O’Bonsawin wrote for the majority. “The distinct offence of aiding suicide was neither charged nor is it a lesser included offence.

“Further, there was no air of reality to a scenario in which [the accused’s mother] self-administered the insulin with an intention to end her own life,” O’Bonsawin added.

The majority restored B.F.’s conviction for the attempted murder of her mother, and left intact the convictions related to B.F.’s child.

Justices Andromache Karakatsanis, Mary Moreau, and Chief Justice Richard Wagner dissented in part.

In her reasons, O’Bonsawin said trial judges “must instruct the jury on each required element of the offences charged in every case, regardless of the circumstances.” However, she added that judges must only instruct juries on defences and included offences “where they have an air of reality.”

Determining whether an air of reality exists requires courts to conduct a “contextual assessment” as to “whether the necessary factual inferences are available on a reasonable view of the evidence,” the justice said.

In R. v. B.F., there was no testimony from the accused’s mother or anyone else that she intended to end her own life, O’Bonsawin noted. The mother also denied injecting herself with insulin.

At its most favourable, the evidence relied on by the accused does not prove there was “an air of reality to the theory that I.F.,” her mother, “had suicidal intent,” the justice said.

In a jointly-authored dissent, Karakatsanis and Moreau said that while they agreed with the majority’s decision to preserve the convictions related to the accused’s daughter, they disagreed that the trial judge gave the jury correct instructions.

“In our view, an air of reality existed at trial for the inference that B.F. provided I.F. with insulin pens, which I.F. then independently and autonomously administered to herself in a suicide attempt,” the justices wrote.

Later, they concluded that the trial judge should have clearly instructed the jury on the difference between attempted murder and aiding suicide.

“Otherwise, there was a risk that B.F. would be found guilty of attempted murder, despite her moral blameworthiness not rising to the level of that offence,” the justice wrote.

“The jury should have been instructed that if it found that I.F.’s choice [to inject herself with insulin] was independent and autonomous, then it should acquit B.F. of attempted murder.”

Karakatsanis and Moreau said they would have upheld the Ontario Court of Appeal’s decision to order a new trial related to the attempted murder of B.F.’s mother.

In a statement to Canadian Lawyer, Elina Marinosyan, a partner at Lawspec PC who represented B.F., said she was disappointed that Friday’s decision did not resolve a key legal question raised in the case: whether supplying the tools for self-harm or suicide can ever be the basis for an attempted murder or murder conviction.

“We are also puzzled as to why the Court granted leave for what we thought was for the purposes of settling a question of national importance and then declined to do so,” Marinosyan said.

A spokesperson for Ontario’s Ministry of the Attorney General did not immediately respond to a request for comment. 

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