"Most people who are serial killers are psycopaths and that is present from a really young age, " Dr Coulton said. "There may not be a precise reason for him to have committed these crimes but he may have traits."
The hosts then asked the psychologists why Chua, who faked his nursing certificate, decided to target people within a hospital.
"The means and the methods at the hospital are easy. It's an area where it’s easier to do so, " she said.
"Speaking to his colleagues, there were signs that he sometimes got angry or irritated with patients and sometimes got aggressive.
"Psychopaths are often great at reading other people, but can't emotionally respond to them."
Amanda asks: "Are our hospitals safe? Do you think we need improved security checks in hospitals?"
Dr Rani responded: "It’s hard to know exactly what happened here.
"The NHS is a very safe organisation as a whole.
"It’s the fifth largest employer in the world. Incidents like this are shocking as it’s a caring profession.
ITVKathleen - One of Chua's surviving victims
"Doctors and nurses give so much to care. Incidents like this make us stop and wonder how this had happened."
"But how did the NHS miss that Chua had a fake diploma?" Phil asks.
"That needs to be looked at, " Dr Rani admits. "We need to have closer relations with the countries we recruit from."
"Should there be practical tests?" Amanda asks.
GMPCCTV of nurse Victorino Chua accessing the medicine cabinet at Stepping Hill hospital
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