The general practitioner who disguised himself repeatedly and injected poison into his mother’s partner because of his inheritance was sentenced to 31 years and 5 months in prison.

Thomas Kwan, 53, was posing as a nurse administering a coronavirus vaccine when he injected the toxin into Patrick O’Hara, 71, in Newcastle in January.

Mr O’Hara, who has a life-threatening flesh-eating disease that causes horrific injuries, previously told Newcastle Crown Court. had become a “shell” of himself.

Kwan, who admitted to attempted murder after the first day of his trial, was described as “calculated and callous” by the sentencing judge.

Prosecutor Peter Makepeace KC said the GP, who worked at Happy House Surgery in Sunderland, spent months planning the “audacious” attack.

The court heard the man was “obsessed” with money and angry that his mother, Wai King Leung, also known as Jenny Leung, created a will in 2021 granting her partner of 21 years a share in his Newcastle home.

Mr Makepeace said Kwan, a wealthy doctor who lived with his wife and young son in a large detached house in Ingleby Barwick, was motivated entirely by greed.

The doctor had installed spyware on his mother’s computer years ago to monitor her mother’s financial situation.

On January 22, Kwan went to Ms Leung and Mr O’Hara’s home in St Thomas Street, posing as a community nurse named Raj Patel, and arranged the visit with several forged letters.

He had hidden behind a face mask and hat and created a false identity, tanning his skin and wearing a black wig with a fake beard and moustache.

The GP drove to Newcastle the night before in a car with false plates and stayed at a nearby hotel under a false name.

At the end of his 45-minute visit, during which he performed blood checks and health surveys, Kwan injected Mr. O’Hara’s arm.

Mr O’Hara said he immediately felt “excruciating pain” but hurried away after his visitor told him it was a normal reaction.

The victim immediately became suspicious when Ms. Leung said the visitor was the same height as her son.

Mr O’Hara spent five weeks in the Royal Victoria Infirmary in Newcastle, during which doctors cut off large chunks of diseased flesh in a desperate attempt to stop necrotizing fasciitis from spreading beyond his arm.

He needed several skin graft surgeries and needed ongoing physiotherapy as well as post-traumatic stress disorder.

Prosecutors believed Kwan used a pesticide called iodomethane; but numerous books, recipes, and terrorism manuals on toxins were also found in his home, as well as numerous other poisons, including ingredients used to make ricin.

Detectives also found evidence of a “backup plan” that involved a fake charity sending free food and wine.

Judge Miss Justice Lambert said it was an “audacious” and thoroughly planned plan “to kill a man in plain sight” and it almost worked.

He said Kwan posed as a public nurse so he could administer a “lethal injection” to his victim and that Mr O’Hara had no reason to suspect his visitor was not real.

The judge said the letters Kwan had prepared were “sophisticated” and that Kwan had managed to gain entry to Mr O’Hara’s home “in the most calculated and callous manner”, which had “undermine public confidence” in the NHS.

Doctors were baffled by Mr O’Hara’s symptoms, he said, adding that he suffered horrific injuries that required extensive treatment.

“Fortunately, he survived, although he suffered the physical and psychological consequences of your attempt to kill him.

“It is clear that he has transformed from the tough and stoic person he was before the attack.”

Ms Justice Lambert said Mr O’Hara suffered from post-traumatic stress disorder, had flashbacks and was separated from Kwan’s mother.

The court heard Kwan was born in Hong Kong and moved to England at the age of 13 to attend boarding school, then went on to study medicine at Newcastle University.

Ms Justice Lambert said it stemmed from a “persistent obsession” with Kwan’s mother’s inheritance, adding: “Your resentment and resentment towards your mother and Mr O’Hara was entirely about money.”

It said Kwan had a “morbid obsession” with poisons, creating a “library of materials” and searching for iodomethane online 97 times in January.

The judge said Kwan was a “dangerous offender” who posed a high risk of serious harm to Mr O’Hara.

The GP was told he showed “shockingly distorted thinking, a marked sense of entitlement and a capacity for the most extreme behavior to meet your own needs”.