Warning: Details in this article may be disturbing and triggering for readers. A man already serving a life sentence for murdering his girlfriend 18 years ago is now on trial in a Muskoka courtroom accused of the Dec. 2022 murder of a fellow inmate in a medium-security prison. The first-degree murder trial of Devon Saunders, 57, got underway with opening statements from both the Crown and defence, where a jury of seven men and five women will decide whether Saunders acted in self-defence as his lawyers suggest. Saunders, with a white beard, wearing a grey suit, sat in the prisoner’s box accused of killing inmate 30-year-old Leslie Ma on Dec. 18, 2022, at Beaver Creek Institution in Gravenhurst. The Crown told the court Saunders carried out the planned murder of Ma, who was found in the kitchen area bleeding from stab wounds. The Crown said Saunders was seen on surveillance video wearing a winter jacket in the common area before striking Ma in the head. Within moments, both men were seen heading toward the kitchen, where Ma was found in distress. “This is a case of the right to self defence, and the right to protect yourself from the people who threaten you and the people who threaten your life,” said one of Saunders’ lawyers Rick Frank. The defence told the jury Saunders, lived in fear for his safety after being jumped in the shower over a long-standing “beef” with an inmate Saunders knew at another prison in Manitoba, where both he and Ma had been prisoners before transferring to Beaver Creek. The Correctional Service of Canada said Ma, who was also from Alberta, was serving a nearly 10-year sentence for drug trafficking. Saunders was previously convicted, in 2015, of first-degree murder in the killing of his girlfriend Shernell Pierre, 26, whose remains were found inside her burned car near the West Edmonton Mall in 2008. In trial, the court heard Pierre had been shot in the back of the head. Evidence in the case against Saunders was largely circumstantial. Saunders was charged four years after Pierre’s death. The defence told the jury Monday afternoon that Saunders has long maintained his innocence while serving a life sentence. Saunders, the defence told the jury, had hopes to one day overturn his conviction working with Innocence Canada, who speak with clients who claim they have been wrongfully convicted of crimes. The defence told the jury Saunders’ problems inside the prison started in the nine months leading up to Ma’s death, when the defence says Ma told Saunders, “I am going to crush you” and “I am going to kill you.” Saunders is also represented by Toronto defence lawyer Sherif Foda. The trial, presided over by Justice Howard Leibovich, is scheduled for three weeks.