The Mayerthorpe tragedy occurred on March 3, 2005 on the property of James Roszko, approximately 11 km (6.8 mi) north of Rochfort Bridge near the Town of Mayerthorpe in the Canadian province of Alberta. With a Heckler & Koch 91, Roszko shot and killed Royal Canadian Mounted Police constables: Anthony Gordon, Lionide Johnston, Brock Myrol and Peter Schiemann. The incident occurred as the officers were executing a property seizure on the farm.