Killer Victorino Chua was described as a narcissistic psychopath by detectives as the "angel turned evil" hospital nurse was convicted of murdering and poisoning patients.
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.
Chaos and panic followed in his wake with 21 poisoned patients suffering sudden illness that left hospital staff in turmoil and police on the brink of closing the hospital for the sake of patient safety.
Two patients, Tracey Arden (44) and Alfred Weaver (83), suffered agonising deaths and a third, Grant Misell (41), was left brain damaged as the overdoses starved the victims' brains of oxygen.
He was cleared of a third murder, of Derek Lancaster (81), but found guilty of attempting to cause him grievous bodily harm.
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 will be sentenced today in the presence of some of his victims' loved ones and faces a mandatory two life sentences for the murders.
Chua, a father-of-two, stood in silence, only blinking as the foreman of the jury, after deliberating for 11 days, delivered guilty verdicts following the trial lasting four months at Manchester Crown Court.
In a letter found at Chua's Stockport home, 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".
Chua, first arrested in January 2012, has shown "a complete lack of remorse" throughout, said Detective Superintendent Simon Barraclough, who led the investigation for Greater Manchester Police (GMP).