On February 10, 2015, Jeffrey Harris was addicted to heroin, selling cocaine to support his 3-4 fixes-per-day habit, living in the village of Lillooet, British Columbia.
Gary Mandseth was Jeffrey Harris’ drug dealer.
Often when Harris showed up at Mandseth’s house to buy more cocaine, Harris testified, Mandseth would inject him with heroin.
In a move that ultimately cost him his own life, Gary Mandseth injected Jeffrey Harris with cocaine instead of heroin that fateful day.
While Harris became mellow and sleepy on heroin, the opposite was true when he was high on intravenous cocaine. Then, Harris would see shadows that terrified him and become extremely anxious.
The following paragraphs the Court of Appeals decision R. v. Harris describes what happened next.
 On February 10, 2015, Mr. Harris drove to the deceased’s house with two women, Tara John and Kathleen Shintah, to purchase crack or cocaine. When Mr. Harris went into the house, the women stayed in the car.
 There were no witnesses to the start of the altercation between Mr. Harris and Mr. Mandseth. Mr. Harris testified that Mr. Mandseth asked him if he was stealing from him and then injected him with a substance. Mr. Harris had often received an injection of heroin when he went to Mr. Mandseth’s house to pick up drugs to sell or use.
 Mr. Harris expected the substance to be heroin but upon receiving the injection, realized it was cocaine. He testified he became very afraid and felt that he was dying. He said that he strongly disliked intravenous cocaine and he believed the deceased had given him a “hot dose”.
Mr. Harris said that as a result of the injection, he felt like “everything went south”, he was drowning and he saw visions of shadows. Mr. Harris testified that the next thing he remembers was a pistol pointed at his face by a police officer at the time of his arrest. He has no memory of attacking Mr. Mandseth.
 Crown witnesses, Jesse Andrew and Ms. Saelens, resided on the floor above Mr. Mandseth. They heard noises and came downstairs to see Mr. Harris in the midst of assaulting Mr. Mandseth. They tried to stop him and called the police. Mr. Harris stated words to the effect of, “I am killing him because he killed me first”. Mr. Harris left the residence shortly after the police were called, taking among other items a bag of heroin.
 Mr. Harris got back into the vehicle and Tara John drove the vehicle away from the residence. The vehicle was chased by police cars. Tara John stopped the vehicle and Mr. Harris fled on foot. Cst. Honeyman and Cst. Kongus followed the appellant and arrested him without incident.
The autopsy showed Gary Mandseth received several stab wounds to his chest, abdomen, hands and arms. He also suffered blunt force injuries to his head, along with scalp lacerations, puncture wounds and fractured fingers.
Cause of death: multiple stab wounds to his chest.
At his 2017 trial, Jeffrey Harris’ attorney argued his client acted involuntarily and therefore lacked the intent required for murder and should be acquitted.
Alternatively, they argued, Harris was too intoxicated from the cocaine injection to possess the requisite intent for murder and should therefore be convicted of manslaughter, not second-degree murder.
During pre-charge conferences, Jeffrey Harris’ defence counsel requested the trial judge to charge the jury on the defence of provocation as well as on the defence of involuntary intoxication. The trial judge refused because he said neither defence met the air of reality test.
The trial judge, with respect to the defence of provocation, said:
As far as provocation, the defence of provocation requires a wrongful act or — act or insult. Here the defence says it was the injection of cocaine rather than heroin.
The difficulty Mr. Harris faces is that he did not assert he was provoked. There is no subjective provocation, that is, the accused did not say “That’s why I stabbed him.”
The accused says he felt the ingestion of cocaine and everything went south. The accused says he has no memory of engaging in the stabbing.
In the absence of a claim by Mr. Harris that he was provoked, the defence of provocation does not have an air of reality and I am not going to include it in the charge. (Transcript p. 507, ll 20–34.)
On April 21, 2017, the jury returned a verdict of guilty of second-degree murder in the death of Gary Mandseth.
Jeffrey Harris was sentenced to life in prison with no chance of parole for 10 years.
Defence lawyers Donna Turko and Talia Magder appealed the conviction on three grounds, alleging the trial judge erred by:
- Failing to instruct the jury on the defence of provocation;
- Failing to instruct the jury on the defence of involuntary intoxication; and
- Failing to properly instruct the jury on the defence of non-mental disorder automatism.
On May 14, 2020, the BC Court of Appeal ruled the trial judge’s decision not to charge the jury with respect to the defence of provocation was an error in law.
 As R. v. Johnson makes clear, the defence of provocation does not depend on direct evidence from an accused that they acted in response to a wrongful act or insult. In this case, Mr. Harris’ statement, “I am killing him because he killed me first”, provides the necessary evidentiary foundation to give an air of reality to the defence of provocation.
 Accordingly, there was evidence upon which a properly instructed jury acting reasonably could draw the inferences necessary to give effect to the provocation defence. The trial judge should have instructed the jury on the defence of provocation. It was for the jury to determine whether the defence would succeed as a matter of fact.
 The trial judge’s failure to put the defence of provocation to the jury is fatal to the conviction for second degree murder. In these circumstances, the only available remedy is a new trial.
The Honourable Mr. Justice Goepel, writing for the BC Court of Appeals, concluded:
“I would allow the appeal, set aside the verdict and order a new trial.”
In September 2019, Jeffrey Harris was released on bail after spending four and a half years in prison.
After the Court of Appeals ruling, Harris was sentenced to time served for the crime of manslaughter and 18 months probation, during which time he must abstain from illegal drugs and stay away from Lillooet.
He is also bound by a lifetime firearms prohibition order.
Jeffrey Harris now lives and works in the Calgary area according to a Kamloops News report.