A Scots nurse dubbed the Angel of Death after being found guilty of six-month killing spree could be victim of a miscarriage of justice, a forensic scientist has claimed.
Colin Norris was jailed for 30 years for the murder of four pensioners and the attempted murder of another at hospitals in Leeds, Yorkshire, by injecting them with insulin.
But an expert in forensic toxicology has now raised fresh doubts over the conviction and said he believed Norris was found guilty with flawed evidence.
The case has long come under scrutiny and the latest claims draw parallels with nurse Lucy Letby, who is serving 15 whole life sentences for murdering seven babies and attempting to murder seven others between 2015 and 2016.
Prof Alan Wayne Jones, a retired expert in forensic toxicology, said he saw ‘close parallels between’ the Letby case and that of Norris.
He said: ‘It’s absolutely possible Colin Norris and Lucy Letby could be cleared of these crimes on appeal, given the weight of evidence that might be gathered to undermine the methodology applied in these trials.’
Letby has already lost two bids to appeal but a panel of medical experts has challenged the evidence against her.
Meanwhile Norris, 48, could be freed in May when the Court of Appeal in London considers claims that evidence against him was largely circumstantial and deeply flawed.
Glasgow-born Colin Norris was jailed for 30 years for the murder of four pensioners and the attempted murder of another at hospitals in Leeds
Bridget Bourke, one of four elderly women murdered by Norris
Prof Jones has authored a paper which claims crucial and incriminating tests in the Norris case did not conform to forensic standards.
And he agrees with many experts that unexplained low bloody sugar, hypoglycemia, which linked deaths of the victims in the Norris case, can occur more often than was thought at the time of his trial creating a clear reasonable doubt for the conviction.
Doubt over the conviction has long remained, with Professor Richard Marks raising his doubts on Norris’ guilty 14 years ago as part of a BBC documentary.
Prof Jones told the Daily Record: ‘Marks discovered the only real evidence in Norris’s case that insulin was used in the death of one of the elderly ladies’ deaths – Ethel Hall.
‘For the other four cases there was no chemical or forensic evidence against him, simply that he happened to be on duty when these elderly ladies died.
‘And when they died they were diagnosed to have hypoglycemia and because Norris was already suspected in the Ethel Hall case they searched the hospital rota and found that he was on duty when his other ladies died and they had hypoglycemia.
‘The prosecution put two and two together and accused Norris of killing these other ladies as well. There is ample evidence to suggest he got a raw deal.’
A new BBC documentary reveals new evidence which could pave the way for the release of Norris
The expert said Ms Hall’s blood sample was analysed using immunoassays, but that is not sufficiency for reliable forensic evidence.
Prof Jones also said another concern arose when Ms Hall’s blood sample was tested for insulin and a compound called C peptide.
He said: ‘They’d already normalised Ms Hall’s blood sugar by giving her intravenous glucose – and that interfered with the results.
‘The lab in Surry was a clinical and not a forensic lab, and there are more stringent routines in forensic science compared with clinical science, so you have to have quite different standards of things like chain of custody, storage or the specimen, stability of the drug.
‘So there are problems with the evidence that make me conclude this conviction is unsafe.’
Norris, who grew up in the Partick area of Glasgow and studied at the University in Dundee, was sentenced at Newcastle Crown Court in 2008.
He has been given the right to appeal after a lengthy battle.
His case will be heard by Court of Appeal judges in May and it is expected to take up to four weeks.