Overview

• The 21-year-old pleaded guilty to murder and attempted murder over the March 4, 2024 attack at the Nortons’ Greenwood home.
• Colin Norton, 81, died at the scene from traumatic head injuries, Margaret Norton suffered serious abdominal wounds, and the family dog was stabbed; police declared a serious armed incident, briefly locked down the area, and arrested Niyonyishi in nearby Kingsley.
• The court heard the violence followed a drunken hotel dispute with the couple’s foster son, with Niyonyishi telling police he wanted the son to feel pain and admitting curiosity about killing; his blood-alcohol reading was 0.095 with no drugs detected.
• The judge imposed a concurrent 10-year term for the attempted murder and set a non-parole period of 18 years, calling the offending “callous and senseless.”
• Defence submissions cited bipolar disorder, hypomania and complex PTSD linked to a traumatic childhood in a Tanzanian refugee camp, and the court was told Niyonyishi later wrote a remorseful letter to the foster son; victim statements portrayed Mr Norton as a selfless protector.