A nurse accused of murdering patients said he predicted the time of one of their deaths because he had developed nurses' "black humour", a court heard.
Colin Norris is accused of murdering patients at two Leeds hospitals
Colin Norris, 31, predicted 86-year-old Ethel Hall would die during his night shift at Leeds General Infirmary.
He told police he said it because "nurses develop a black sense of humour", Newcastle Crown Court heard.
Mr Norris, of Egilsay Terrace, Glasgow, denies murdering four elderly patients at two Leeds hospitals in 2002.
He is charged with the murders and attempted murders of Mrs Hall, of Calverley, Doris Ludlum, 80, of Pudsey, and Bridget Bourke, 88, of Holbeck, at Leeds General Infirmary between June and December 2002.
He is also charged with the murder and attempted murder of Irene Crooks, 79, of Leeds, at St James's Hospital in October 2002, and the attempted murder of Vera Wilby, 90, at the infirmary
The jury heard the women's bodies contained large amounts of insulin which caused them to slip into comas from which they could not be revived.
The prosecution alleged all were victims of Mr Norris and died because he injected them with insulin.
Before Mrs Hall died Mr Norris told a colleague she did not look well and would die at about 0515 BST, the court heard.
Robert Smith QC, prosecuting, said Mr Norris told police: "It was probably said in a joking manner."
Mr Smith added the nurse told police he had been "unlucky" that the women had died while he was on duty.
The barrister said: "When asked what he meant by that, he said he had been on duty when a few patients had died on wards he was working on."
The trial, which is expected to last until February, continues.