A doctor who wore a disguise when he injected his mother’s partner with poison in a dispute over an inheritance has admitted attempted murder.
Thomas Kwan, 53, had previously denied the offence against Patrick O’Hara, who was given a toxin which caused a “rare and life-threatening flesh-eating disease,” Newcastle Crown Court heard.
Prosecutors said Kwan went to “extraordinary” lengths to disguise himself and prepare the attack at the victim’s Newcastle home on 22 January.
Kwan, who lived in Ingleby Barwick, Teesside, and worked in Sunderland, is due to be sentenced on 17 October with Judge Mrs Justice Lambert saying he can expect a “substantial” prison term.
Kwan had admitted administering a noxious substance to Mr O’Hara, 71, but initially claimed he only wanted to cause “pain and discomfort”, the trial had heard.
But after prosecutors opened the case on 3 October, Kwan changed his plea to the more serious charge on Monday with jurors asked to formally return a guilty verdict.
In his opening speech, prosecutor Peter Makepeace KC said it had been an “audacious” plan that was “stranger than fiction”.
He said Kwan’s mother, Wai King also known as Jenny Leung, had made a will leaving her home in Newcastle to her partner of 20 years, Mr O’Hara with it only passing to her children in the event of his death.
Mr Makepeace said Kwan, who had been a well respected GP, was “obsessed” with money and his inheritance so hatched an “intricate” plan to eliminate the “impediment” posed by Mr O’Hara.
Kwan sent his victim letters purporting to be from the NHS saying he was eligible for a home visit from a community nurse for a medical check-up.
The GP disguised himself with a mask and glasses and carried out the visit himself, also offering the victim a Covid-19 booster jab.
Mr O’Hara felt a “terrible pain” as soon as the injection was given with the visitor making a swift exit, the court had heard.
The victim became suspicious when Ms Leung said the nurse was the same height as her son and then sought medical help.
Mr O’Hara ended up being treated for necrotising fasciitis at Newcastle’s Royal Victoria Infirmary and had to have parts of his arm removed, Mr Makepeace said.
Kwan, who the court heard had a borderline “obsession” with poisons and how to kill people, never revealed what he had injected his victim with.
But searches of his home on Brading Court found multiple chemicals and toxins as well as books and manuals on making and using poisons.
Scientists concluded it was most likely a pesticide called iodomethane which was found in a syringe and would have caused Mr O’Hara’s symptoms, although it had never previously been seen to have been used on a human before.
The court heard Kwan travelled to Newcastle the night before the attack having put false registration plates on his car and checked into a hotel using a fake name.
Kwan had also installed spyware on his mother’s computer so he could monitor the couple’s activities online and take pictures of them using the inbuilt camera without their knowledge.
He had also devised a back-up plan and had created a letter from a fake charity offering Mr O’Hara free drinks and meals, the court heard.
His barrister Paul Greaney KC said Kwan “entirely” accepted prison would be “inevitable” and was keen to be sentenced as quickly as possibly.
Mrs Justice Lambert said there would be a “a substantial custodial term”.
He is due to be sentenced after the probation service has prepared a report.
Speaking outside court after Kwan changed his plea, Det Ch Insp Jason Henry of Northumbria Police said the doctor’s actions had been “despicable”.
He said “scheming” Kwan used his experiences as a GP to “deceive” the victim and cause him “unimaginable pain and suffering”.
Mr Henry said Kwan “thought he had covered his tracks” but officers were able to arrest him within two days of the attack, adding the weight of evidence against him had been “overwhelming”.
The detective also praised Mr O’Hara saying he had bravely got through a “horrendous ordeal” which changed his life “forever”.
Kwan has been suspended by the General Medical Council since February.
Happy House surgery, where he had worked, said he left following his arrest and an audit of practice records was carried out.
“We are satisfied that this was an unrelated, personal matter and at no point did Dr Kwan pose a threat to any of our patients,” a spokesperson said.