WARNING: This story contains graphic details of violence. A teacher and three of her former high school students say there were no warning signs before a fatal stabbing unfolded in their Edmonton-area classroom on the morning of March 15, 2021. Witnesses began testifying this week at the first-degree murder trial of Dylan Pountney, charged in the killing of his 17-year-old classmate, Jennifer Winkler. Pountney, now 22, was 19 at the time. The two were students at Christ the King School, a Catholic Grade 9 to 12 school in Leduc, just south of Edmonton. The gallery in Wetaskiwin's Court of King's...