A former nurse is awaiting sentence after being convicted of killing four elderly patients.Colin Norris killed the four women by injecting them with lethal doses of insulin. He was also convicted of the attempted murder of another patient.The 32-year-old carried out his killing spree at Leeds General Infirmary and St James' hospital in 2002.He tried and failed to kill 90-year-old Vera Wilby, leaving her brain damaged.He succeeded in killing 88-year old Bridget Bourke, 79-year-old Irene Crooks, 86-year old Ethel Hall and Doris Ludlum, who was 80.Norris was supremely confident he would get away with his crime. He told his colleague that his final victim, Ethel Hall, would die on his shift.When the elderly lady did, the colleague alerted authorities.© Independent Television News Limited 2008. All rights reserved.