BBCNew expert knowledge may mean the conviction of a former nurse for the murders of four elderly patients in Leeds was unsafe, the Court of Appeal has heard.
Colin Campbell, formerly known as Colin Norris, was found guilty in 2008 of killing four women and attempting to kill a fifth by injecting them with insulin.
However, the Criminal Cases Review Commission (CCRC), which referred the case to the Court of Appeal four years ago, said prosecutors had relied on a “wholly circumstantial” case.
Michael Mansfield KC, for Campbell, told the court developments in medical knowledge meant there was more evidence to support the argument the patients may have died from natural causes.
Campbell, who was originally from Glasgow, was convicted of murdering Doris Ludlam, 80, Bridget Bourke, 88, Irene Crookes, 79, and 86-year-old Ethel Hall.
All four were elderly inpatients in 2002 on orthopaedic wards where Campbell worked and each died after developing severe, unexplained hypoglycemia.
Campbell was alleged to have been present when or shortly before each of the patients suffered hypoglycemia and, because of the rarity of such a cluster of cases happening within a short space of time, prosecutors said the nurse must have been responsible.
He was also found guilty of attempting to murder 90-year-old Vera Wilby and sentenced to life imprisonment with a minimum term of 30 years.
During his five-month trial, Campbell denied any wrongdoing and said he did nothing to cause hypoglycemia in any of the patients.
Speaking at the start of his appeal hearing, Mr Mansfield told the court: “The approach of the witnesses we intend to call on behalf of the appellant indicates an evolution of understanding, of knowledge, about hypoglycemia and about glucose generally.
“So we say there is now a range of possibilities relating to natural causes.”
PA MediaCampbell unsuccessfully appealed against his conviction in 2009 and applied to the CCRC in 2011.
In referring the case, the CCRC said new expert evidence suggested the women may have died from natural causes and so there was a real possibility the Court of Appeal may find the conviction unsafe.
Mr Mansfield also told the court that toward the end of Campbell’s trial, the jury had asked if there were other cases of patients suffering from “sudden and profound” hypoglycemia in any of the Leeds teaching hospitals after Campbell stopped working.
Four such cases have since been identified, Mr Mansfield told the court, with the deaths recorded between January 2003 and August 2005, and that “no-one is suggesting that these cases were anything other than natural causes”.
He also said all the patients in the nine cases were of “remarkably similar” ages, being between 79 and 93, but it was not “discussed” at the trial.
James Curtis KC, for the Crown Prosecution Service, which opposes the appeal, is due to give oral submissions at a later date.
The appeal, before Lady Justice Macur, Sir Stephen Irwin and Mr Justice Picken, is expected to last three weeks.
