Filipino nurse Victorino Chua was jailed for life after being found guilty of murdering two patients and poisoning 22 others by contaminating saline drip bags with insulin at Stepping Hill hospital in Greater Manchester.
The 49-year-old, described by police as "narcissistic and psychopathic", was convicted of killing Tracy Arden and Alfred Derek Weaver during a "reign of terror" at the hospital in Stockport. He was sentenced to a minimum of 35 years in jail.
Chua injected insulin, which causes a drop in blood sugar levels, into the drips and then returned them to storage only for unsuspecting colleagues to later administer to patients.
As well as causing the deaths of two people on the hospital wards between June 2011 and January 2012, Chua was also convicted of intentionally causing grievous bodily harm to another who suffered a brain injury as a result of being poisoned and grievous bodily harm to a further 21 patients.
Judge Justice Openshaw said: "It's a strikingly sinister and truly wicked feature of this case that he did not personally administer the contaminated products to patients but having left saline bags and ampoules in the treatment rooms he didn't know which nurse would collect them -- still less which patient the nurse would then administer it to.
"It's as if he left it to fate as to who would be his victim."
Chua was arrested in January 2012 after investigations found he had been the only member of staff present at the hospital on three key occasions; When five patients were poisoned overnight, when contaminated ampoules were found and when prescription charts were fraudulently altered on 3 January 2012.
Following his arrest, officers also found a note at Chua's home in which he described himself as an "angel turned into an evil person" who had done things he would "take to the grave".
An investigation is also under way into claims the father of two may have fraudulently obtained his medical qualifications before coming to work in the UK.
Det Supt Simon Barraclough, of Greater Manchester Police, said: "Hidden in plain sight and using unsuspecting colleagues to carry out his sinister plan, Victorino Chua deliberately poisoned and murdered those who were under his care and those who were at their most vulnerable and most in need of help.
"Chua has demonstrated clear narcissistic and psychopathic tendencies and such indiscriminate poisoning is testament to that. He clearly had no regard for his patients and did not give a second thought as to who would be injured or the devastation this would cause them and their families.
"It is so far from keeping with the ethos of those employed at the hospital or as health professionals generally that it is incredulous to believe someone in that vocation to be capable of such malevolence."