"Angel turned evil" killer nurse Victorino Chua is facing life in jail in the UK after he was found guilty of a murderous poisoning spree at his hospital.

Filipino Chua, 49, injected insulin into saline bags and ampoules while working on two wards at Stepping Hill Hospital in Stockport in June and July 2011.

These were then unwittingly used by other nurses on the ward - leading to a series of insulin overdoses to mainly elderly victims.

The father of two daughters was convicted of murdering two patients.

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He was cleared of a third murder but found guilty of attempting to cause that patient grievous bodily harm.

Chua stood in silence, only blinking as the foreman of the jury, after deliberating for 11 days, delivered the verdicts following the trial at Manchester Crown Court.

He will be sentenced tomorrow in the presence of some of his victims' loved ones and faces a mandatory two life sentences for the murders.

The Crown said Chua decided to take out his personal frustrations on patients "for reasons truly known only to himself".

After police were called in, Chua "changed tack" by sabotaging prescription charts, doubling and trebling dosages - some with potentially lethal consequences - leading to his arrest in January 2012.

Among the evidence produced by the prosecution was a self-penned letter found at Chua's home in Stockport after his arrest.

In the letter, described as "the bitter nurse confession" by Chua, he said he was "an angel turned into an evil person" and "there's a devil in me". He also wrote of having things he would "take to the grave".

He was found guilty of murdering Tracy Arden, 44, and Alfred Weaver, 83. He was cleared of murdering Arnold Lancaster, 81, who was suffering from terminal cancer, but convicted of attempting to cause him grievous bodily harm with intent by poisoning.

Ms Arden, who had multiple sclerosis, was admitted for a "mild" chest infection and would have expected to "sail through this storm". But she was pronounced dead eight hours after admission after being treated with a saline ampoule contaminated with insulin.

Mr Weaver was admitted with a chest infection and, after being given a saline drip, he "appeared to be in agony, eyes rolling back in his head". He died 10 days later.

In his closing speech to the jury of six men and six women, prosecutor Peter Wright QC said the "bitter nurse confession" was "a living and unfinished document".

"There was unfinished business. It is a narrative of his life, of his feelings, of his pent-up frustrations. It was a portent of things to come and of what he had done.

"It is an insight into his thought process during a period of considerable anger and disharmony, both at home and at work which coincided with these events.

"The evidence points sadly to a man who, for reasons truly known only to himself, decided to take out his frustrations on his and others' patients."

Chua's defence team said he had been wrongly singled out and made "a scapegoat".

Peter Griffiths QC said the effort that Greater Manchester Police put into the investigation resulted in "huge pressure" to bring someone to account.

Another Stepping Hill nurse, Rebecca Leighton, was arrested and charged in the early stages of the investigation and locked up for more than a month before she was released without charge, the jury heard.

But Chua was the only nurse who was on duty at all the relevant times outlined in the prosecution case against him.

In all, Chua was convicted of two murders, 22 counts of attempted grievous bodily harm, one count of grievous bodily harm, seven attempts of administering poison and one count of administering poison.

He was cleared of one count of murder, one count of manslaughter and one count of attempting to administer poison.

In June and July 2011 a growing feeling of unease and "something not right" overtook medics after one patient after another suddenly began falling inexplicably ill on Chua's wards at Stepping Hill Hospital.

On the nightshift of July 10/11, five patients had unexpected hypoglycaemic attacks, a naturally rare event, which suddenly became "alarmingly common".

A similar pattern followed of "rollercoaster" blood sugar levels for the poisoned patients, who soon rallied after being given glucose sugar infusions, only before they relapsed again from the insulin, unknown to medics, still in their drips.

Many patients went "full circle" and recovered, but three died, two of them as a direct result of the poisoning, the jury ruled with their murder verdicts, and a fourth, Grant Misell, was left with permanent brain damage.

Mr Justice Openshaw told the jury he will sentence Chua tomorrow, with many relatives of his victims expected to attend the hearing to see him jailed for life.

He told jurors: "My thanks, and the thanks of the community, for the part you have played in the administration of justice in this very important trial."

He told jurors they were excused for life from serving on a jury again, if they so wish.

Police and detectives hugged members of the legal team after the jury left court.

Operation Roxburg, a multimillion-pound three-and-a-half-year police investigation, was one of the biggest and most complex launched by Greater Manchester Police, involving 7,700 police actions, 659 witnesses, a 28,100-page prosecution file and 16,000 items of unused evidence material.

Outside court, Detective Superintendent Simon Barraclough said: "It's been a search for the truth and the jury has reached the right decision."

Ben Southam, from the CPS North West Complex Casework Unit, said: "The investigation and prosecution has been an enormous task involving the detailed analysis of thousands of pages of evidence relating to the hospital, its staff and patients, the forensic analysis of medical products and samples, expert medical evidence and many other aspects of what has been a very complex case.

"The only possible conclusion from all the evidence is that Victorino Chua, trusted as a nurse to care for sick patients at the hospital, was the person responsible for harming and, in two cases, for killing them.

"I would like to thank all the witnesses who gave evidence during the trial, particularly the victims, the relatives of the patients who died and the staff from Stepping Hill Hospital.

"Above all our thoughts and sympathies go out to all the victims and their families at this time."