Law360 Canada (May 28, 2026, 10:12 AM EDT) --

John L. Hill

A southern Alberta man was sentenced to five-and-a-half years, less time served, in connection with a fatal attack on 33-year-old Linden Grier in 2021.

Cullen Drake Tailfeathers, a member of Alberta's Kainai Nation, was found guilty of manslaughter on May 2, 2024. The court said Grier’s death resulted from a heated dispute between Tailfeathers and his ex-partner, Chantelle English. Grier was described as a loving father of three who had obtained full custody of his children only weeks before he died. Tailfeathers was 25, stood six feet six inches, and weighed 300 pounds, considerably bigger than Grier, who was five foot eight and 180 pounds. Tailfeathers appealed his conviction to the Alberta Court of Appeal.

If successful, the appeal would have upended Canadian law, which is believed to stipulate that where a fight escalates to the point of causing non-trivial harm, consent is legally invalid. A decision was released on May 25, 2026.

The case concerned Grier’s death after a violent confrontation with Tailfeathers, who had been in a deteriorating, toxic romantic relationship with English. In the days before the incident, the relationship had broken down. On the night in question, English, who was heavily intoxicated, posted humiliating social media content about Grier, including a shirtless photo of him in her home. Tailfeathers became angry and upset after seeing the posts. He sent a series of increasingly emotional and threatening text messages to English, demanding to know whether she had slept with Grier and warning that he might “hurt someone” or come to the house.

Despite later claiming he only wanted answers and intended to return the apartment keys and retrieve his belongings, Tailfeathers drove approximately 62 kilometres from Cardston to English’s residence in Fort Macleod in the middle of the night. After arriving, he argued with English, then went into the basement, where he encountered Grier. Tailfeathers testified that Grier adopted an aggressive fighting stance, prompting him to fear for his safety and strike first in self-defence. According to his account, the two men exchanged blows for less than 15 seconds before Tailfeathers landed a final punch below Grier’s ear, causing Grier to fall unconscious and suffer fatal head injuries.

Following the confrontation, Tailfeathers sent additional messages to English that were highly incriminating, including statements such as “Should I come back and finish him off?”, “I will finish his pathetic life off”, and “Any time you try to get me jealous with another man, I’ll do that over and over again.” Although he later claimed these texts were written out of anger, panic and emotional distress rather than genuine intent, the Crown relied heavily on them to show motive and aggressive intent.

Medical evidence established that Grier died from blunt head trauma, including bleeding on the brain. He was heavily intoxicated with alcohol and cannabis at the time of death. Tailfeathers maintained throughout the trial that he had acted in self-defence and had not gone to the home seeking violence.

The trial judge accepted that there was an “air of reality” to the self-defence claim but ultimately rejected Tailfeathers’ evidence as not credible. The judge found that his testimony conflicted with the plain meaning of his text messages, which showed he travelled to the home intending to confront and fight Grier. The judge also found Tailfeathers’ account internally inconsistent and implausible, particularly given the substantial size difference between the sober accused man and the much smaller, intoxicated Grier.

The court further relied on testimony from English’s children and forensic observations by a police officer, neither of which supported Tailfeathers’ account of a mutual fistfight. The judge concluded that the Crown had disproved self-defence beyond a reasonable doubt and found that Tailfeathers intentionally applied force that caused Grier’s death. Tailfeathers was convicted of manslaughter on the basis that a reasonable person would have known the assault posed a risk of significant bodily harm.

The appellate court dismissed the appeal and upheld the manslaughter conviction, finding that the trial judge’s reasoning, credibility assessments, and rejection of self-defence were supported by the evidence (R. v. Tailfeathers, [2026] A.J. No. 606).

The court first rejected the argument that the trial judge improperly relied on assumptions about the lack of injuries to Grier’s hands and his severe intoxication. The court emphasized that trial judges are entitled to draw reasonable inferences from both the evidence and its absence. Here, there was ample evidentiary support for the findings. A forensic investigator with 24 years of experience testified that Grier’s hands showed almost no bruising, cuts or discoloration, despite Tailfeathers’ claim that Grier repeatedly punched him during a mutual fistfight. The autopsy report likewise documented extensive injuries to Grier’s head and body but virtually none to his hands. The court held that the trial judge was entitled to infer that, if a fight occurred as described by Tailfeathers, some evidence of injury to Grier’s hands would likely have been present. Expert evidence was unnecessary because this was a commonsense inference grounded in the evidence.

The court also found clear evidence supporting the trial judge’s conclusions about Grier’s intoxication. Toxicology results showed that his blood alcohol level was extremely high, consistent with confusion, impaired coordination and reduced reflexes. The trial judge, therefore, did not improperly take judicial notice of intoxication; the medical evidence itself supported the finding that Grier would likely have lacked the coordination and physical capacity to engage in the balanced exchange of blows described by Tailfeathers.

Although the Crown conceded that the trial judge misapprehended one aspect of Tailfeathers’ testimony, namely who threw the first punch, the appellate court held that the error was not material to the outcome. Tailfeathers had consistently testified that he struck first because he believed Grier was acting aggressively. However, the court concluded that this mistake did not undermine the conviction, as the trial judge provided numerous independent reasons for rejecting the appellant’s self-defence claim.

Central to the court’s reasoning were Tailfeathers’ text messages before and after the confrontation. The messages showed escalating anger, jealousy and threats toward Grier. Tailfeathers warned he might “hurt someone,” said he would “come there,” threatened to “hurt him,” and after the assault suggested he should “come back and finish him off.” The appellate court agreed with the trial judge that these texts revealed Tailfeathers’ true motive: he intentionally went to English’s home to confront and fight Grier, and that motive intensified throughout the night.

The court also upheld the trial judge’s finding that Tailfeathers’ account of a fair, mutual fistfight was implausible. The evidence showed a significant size disparity between the men, with the appellant substantially larger and sober, while Grier was severely intoxicated. The trial judge was entitled to conclude that Grier could not likely engage in the rapid, evenly matched exchange of blows described by the appellant.

Further support for the conviction came from the testimony of English’s children, whom the trial judge found credible and reliable. Their evidence described Tailfeathers entering the house and immediately heading to the basement, where the confrontation occurred. English’s daughter described seeing Tailfeathers swinging at Grier, who appeared to be lifted upward during the assault, contradicting Tailfeathers’ account of a consensual or evenly matched fight.

The appellate court also rejected the argument that the trial judge’s reasons were insufficient. It found them lengthy, detailed and fully amenable to meaningful appellate review. The trial judge carefully reviewed the law of self-defence under s. 34 of the Criminal Code and applied the governing principles set out in R. v. Khill, 2021 SCC 37. The reasons demonstrated that the judge understood the Crown’s burden to disprove self-defence beyond a reasonable doubt and explained why the appellant’s evidence failed to raise a reasonable doubt.

Ultimately, the appellate court agreed that Tailfeathers unlawfully assaulted Grier and that the assault was a dangerous act carrying a foreseeable risk of bodily harm. The court accepted the trial judge’s conclusion that the confrontation was not a consensual fight but an attack initiated by Tailfeathers after he deliberately travelled to the home in anger. The Crown had therefore proven beyond a reasonable doubt that Tailfeathers was not acting in self-defence when he struck and killed Grier.

The appeal was dismissed in its entirety.

John L. Hill practised and taught prison law until his retirement. He holds a JD from Queen’s and an LLM in constitutional law from Osgoode Hall. He is also the author of Pine Box Parole: Terry Fitzsimmons and the Quest to End Solitary Confinement (Durvile & UpRoute Books) and The Rest of the (True Crime) Story (AOS Publishing). Contact him at johnlornehill@hotmail.com.

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