A GP has admitted plotting to kill his mother’s long-term partner by disguising himself as a community nurse and poisoning him with a fake Covid booster jab.
His victim, Patrick O’Hara, 72, was left with a rare flesh-eating disease as a result of the injection in his arm.
Thomas Kwan, 53, was on trial at Newcastle Crown Court and had initially denied attempted murder, but changed his plea after he heard the prosecution open the case against him.
Police initially thought the married father-of-one had used the chemical weapon ricin to try to kill Mr O’Hara at his mother’s home in St Thomas Street, Newcastle, on 22 January, but an expert believed a pesticide was more likely.
The Hong Kong-born doctor had developed an “encyclopaedic knowledge” of poisons, the court heard, and he studied how to get away with murder, police discovered from analysis of his home computers.
His actions sparked a major emergency services operation after lethal chemicals were discovered by police in a detached garage at his home in Ingleby Barwick, Teeside.
The Sunderland-based GP had already pleaded guilty to administering a noxious substance, claiming he had meant to cause no more than mild pain.
The court heard that Kwan was “money-obsessed”, and that Mr O’Hara posed a “potential impediment” after his mother said in her will that he could remain at her property if she were to die before him.
Opening the case on Thursday, Peter Makepeace KC, prosecuting, said: “Mr Thomas Kwan, the defendant in the case, was in January of this year a respected and experienced medical doctor in general practice with a GP’s surgery based in Sunderland.
“From November 2023 at the latest, and probably long before then, he devised an intricate plan to kill his mother’s long-term partner, a man called Patrick O’Hara. On any view, that man had done absolutely nothing to offend Mr Kwan in any way whatsoever.”
Kwan forged NHS documentation to set up a home visit with Mr O’Hara, after contacting him and claiming to be a community nurse called Raj Patel.
Mr Makepeace said: “As, I suspect, would any of us, Mr O’Hara fell for it hook, line and sinker: he had not the slightest suspicion that this was anything other than a genuine NHS community care initiative, which he warmly welcomed and was grateful for.”
After checking in to a city centre hotel using a fake name, Kwan travelled to his mother’s house wearing a disguise and using false number plates.
Wearing a long coat, a medical mask and tinted glasses, Kwan, in what the court heard was broken English with an Asian accent, told Mr O’Hara he needed a Covid booster, even though he had only had one three months earlier.
Mr O’Hara shouted in pain when it was administered, and Kwan quickly packed his equipment up and left, reassuring his victim that a reaction was not uncommon.
The pain continued, and Mr O’Hara began to suspect that something had gone badly wrong. The next day his arm had blistered and was seriously discoloured, and medics at the hospital were baffled.
He had developed the flesh-eating disease necrotising fasciitis, and needed to have part of his arm cut away to stop it from spreading. He spent several weeks in intensive care.
The fake nurse’s movements were traced using CCTV, and police were able to identify Kwan as a suspect.
Searches of his home in the executive estate where he lived revealed an array of chemicals such as arsenic and liquid mercury, as well as castor beans, which can be used to make the chemical weapon ricin.
Police found a recipe for ricin on his computer, but Ministry of Defence poisons expert Professor Steven Emmett, although still not sure which poison was used in the attack, thought it was more likely that Kwan had used iodomethane, which is commonly used in pesticides.
In the years before the attack, Kwan had had a strained relationship with his mother, Jenny Leung, over her decision to include Mr O’Hara in her will, which led to police being called in November 2022 after Kwan burst into her home.
He went on to install spyware on his mother’s laptop so that he could secretly monitor her finances.
Mrs Justice Lambert said she would sentence Kwan next Thursday once the issue of how dangerous he is had been considered by the Probation Service.
