New expert knowledge may make nurse's murder convictions unsafe

New knowledge may mean the conviction of a former nurse for the murders of four elderly patients in Leeds is unsafe, the Court of Appeal has heard.

- by Charles Brown

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. All were elderly inpatients in 2002 on orthopaedic wards where Campbell worked and each developed severe, unexplained hypoglycemia.

Prosecutors relied on a "wholly circumstantial" case, the Criminal Cases Review Commission (CCRC) said after referring the case to the Court of Appeal in London four years ago. 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.