Thomas Kwan: Inside story of evil doctor who injected stepfather with pesticide-laden ‘COVID’ jab

In the quiet cul-de-sac that he called home, the comings and goings of Dr Thomas Kwan raised no suspicions.

And why would they? Middle-aged and married with a young son, the 53-year-old GP was the very picture of respectability.

But Kwan was hiding a deadly secret.

And the key to that secret was to be found in the garage beside his £400,000 house in Teesside.

Inside was an array of highly toxic chemicals, including liquid mercury, thallium, sulphuric acid and arsenic.

Also stored there was a container full of castor oil beans and a “recipe” for how to turn them into ricin – a deadly poison for which is there is no antidote.

Just a few micrograms is sufficient to kill.

The toxin featured in Breaking Bad, the American crime drama about a chemistry teacher called Walter White who turns to drug dealing to solve his financial problems.

Unsuspected by all, he uses his knowledge to make and sell methamphetamine.

As his life spirals out of control, he produces a batch of ricin to poison a rival dealer.

Kwan’s descent from medical practitioner to master poisoner was no less remarkable.

And, like Walter White, his motivation was money.

Kwan wanted to be the only beneficiary of his 73-year-old mother’s will, but was concerned that her long-time partner, Patrick O’Hara, stood in the way of his inheritance.

And so it was he dreamt up an extraordinary plan that would use his medical skills and knowledge to attempt to kill his “rival”.

Having developed an “encyclopaedic knowledge” of toxins, earlier this year he tricked Mr O’Hara into believing he was due a home check-up from an NHS community nurse.

On the day, Kwan turned up at the home that his mother shared with Mr O’Hara in Newcastle, in disguise and talking in broken English using an Asian accent.

His act was good enough to fool his mother, who got him to check her blood pressure while he was there.

Kwan then injected Mr O’Hara with what he claimed was a COVID booster. Almost instantly Mr O’Hara felt an agonising pain in his arm.

Two days later he was admitted to hospital after developing necrotising fasciitis – a potentially fatal flesh-eating disease – and had to undergo emergency surgery to have part of his arm cut away to stop the infection spreading.

Police were called and they were eventually able to trace the journey taken by the “community nurse” all the way back to Kwan’s house – about 37 miles away near Stockton-on-Tees.

At the same time, medics were desperately battling to work out what poison he had administered to Mr O’Hara – who had to spend several weeks in intensive care – and even enlisted the help of a Ministry of Defence scientist with expertise in chemical warfare.

Following the discovery of Kwan’s garage laboratory, ricin was one of the chief suspects, although it is now thought the substance used was a highly toxic pesticide called iodomethane.

Mr O’Hara survived and Kwan was charged with attempted murder, which he denied, and on Thursday his trial got under way at Newcastle Crown Court.

But after the prosecution had outlined their case to the jury, Kwan on Monday pleaded guilty to attempted murder.

He was remanded in custody and will be sentenced next week.

Judge Mrs Justice Lambert warned him: “There will be a substantial custodial term.”

Kwan’s plot had been months in the making.

His motherr, Wai King Leung, known to family and friends as Jenny, had been born in Hong Kong but settled in the UK with her son and daughter.

She worked on the tills at Marks & Spencer and for more than 20 years, had been living with Mr. O’Hara, a 72-year-old father-of two and a grandfather.

According to neighbours, they had met when Mr O’Hara, a loft installer, was working on her property – a Georgian maisonette in a Grade II-listed building in Newcastle city centre.

“Patrick retired probably five or six years ago,” a neighbour told the Mail.

“We got on OK. They’re ordinary people – nice to speak to. She seemed like a caring person. She’d say things like, ‘You need to wear a thicker coat, put your hood up, get out of the rain.’”

Another neighbour added: “Patrick is a lovely lad, a Geordie. He was very quiet, but dead polite and a really nice personality.”

Despite the length of his mother’s relationship with Mr O’Hara, Kwan had met him on only a few occasions when visiting. Even then there was only ever the briefest exchange of pleasantries.

More recently, relations between mother and son deteriorated badly – largely over her will. Ms Leung owned her £200,000 (AUD$387,000) flat outright.

Under the terms of her will, written in September 2021, Mr O’Hara would be allowed to live there for the rest of his life.

Only when he died, or gave permission, could it be sold and the proceeds inherited by Kwan and his sister.

It is unclear if Kwan was under financial pressure.

In 2010 he paid £360,000 ($697,000) for his detached house on an executive development in the town of Ingleby Barwick.

There is no mortgage on the property.

Having completed his medical degree at Newcastle University in 1996, Kwan started work as a hospital doctor before entering general practice.

Until his arrest, he was working as a partner at the Happy House Surgery in Sunderland, a position that typically pays about £140,000 ($271,000) a year.

Nonetheless, Kwan continually badgered his mother about money – so much so that she stopped taking his calls or responding to his emails.

Then, in November 2022, Kwan turned up at his mother’s home unannounced.

“He forced his way into the property, pushing past Mr O’Hara to get to his mother, pestering her once more about her financial affairs,” prosecutor Peter Makepeace KC told the court.

The row was so bad that Mr O’Hara called the police, who spoke to Kwan about his behaviour.

But aware how it might affect his job as a GP, the couple told officers they did not want the matter taken any further.

Kwan had other ideas.

At some stage he placed spyware onto the home computer used by his mother and Mr O’Hara.

The court heard it allowed him to monitor emails and any internet searches undertaken. In particular, he was monitoring his mother’s financial dealings.

Using the camera integrated into the device he was also able to watch the couple as they used it.

Meanwhile, on his own computer, Kwan started to amass a library of literature dedicated to poisons and poisoning.

Books and papers he downloaded included: Ten Poisons Used To Kill People, The Mujahideen Poisons Handbook, The Terrorist’s Handbook and Forensic Science And Medicine: Criminal Poisoning.

Kwan also started to stockpile chemicals in his garage. Some were ordered through a company he set up and for which he claimed to be its research officer.

He gave its registered office as his GP surgery, telling the practice manager to forward anything delivered to the company to him.

Substances included thallium – a difficult to detect poison – potassium cyanide and iodomethane.

The next step in Kwan’s plan, the jury was told, was to find a way to administer the poison.

In November last year, Mr O’Hara received a letter on NHS headed paper explaining he had been selected for a home visit by the community nursing team.

“Its use of medical terminology, its deployment of NHS hyperlinks and data protection privacy notices gave it a chilling authenticity,” the prosecutor told the court.

In fact it had been drawn up by Kwan on his home computer.

A second letter followed, offering Mr O’Hara a visit on January 22.

The night before, Mr O’Hara even received a text message reminding him of the appointment.

The message had been sent from Kwan’s phone, but he had disguised it by using a sim card with a different number to his usual one.

Kwan then set off from home in his Toyota Yaris, to which he had fitted false numberplates, and checked into a Premier Inn in Newcastle.

At 9am the next morning he was caught on CCTV emerging from the hotel wearing a long coat, flat cap and tinted spectacles.

He had blue surgical gloves on and a clinical mask covering his face.

Arriving at his mother’s house, Kwan spent ten minutes going through a medical questionnaire with Mr O’Hara.

He then took his blood pressure and drew two vials of blood.

At one point, Ms Leung, entirely unsuspecting, asked Kwan to take her blood pressure.

He did this and then told Mr O’Hara he was eligible for a COVID booster, which was administered into his left arm.

“Immediately Mr O’Hara felt a terrible pain and jumped back,” the prosecutor said.

“He shouted ‘Bloody hell’ and explained the immediate and intense pain, but the nurse reassured him it was not an uncommon reaction and it was nothing to be concerned about.”

Kwan packed his bag and left. Mr Makepeace continued: “As he left the home, Ms Leung commented that the nurse had been the same height as her son. Upon that comment – and for the first time – Mr O’Hara began to suspect something was very wrong.”

He went to A&E, where he was given antibiotics and painkillers.

But the following day the injection site was blistering, so Mr O’Hara returned to hospital, where he was diagnosed with necrotising fasciitis.

He underwent a number of emergency operations but remained dangerously ill in intensive care for weeks as medics tried to identify the poison he had been injected with.

Police had been alerted following Mr O’Hara’s admission to hospital.

On February 5 the doctor was arrested for attempted murder.

Kwan refused to tell officers what he had administered, but the discovery of the castor oil beans and ricin recipe led detectives to believe this was what had been used.

Only later did the focus shift to iodomethane, after a syringe filled with the pesticide was found in the garage.

The substance has never been used in a recorded poisoning before – and police believe this was no accident.

It meant it would be much harder to identify and treat. Mr Makepeace told the jury: “If you want to not only inject a substance that causes necrotising fasciitis, but make it as difficult as possible for the medical team, iodomethane is the one to pick from the many substances available to Mr Kwan.”

While the substance used may have been in doubt, Kwan’s role was not.

From his computer, police recovered the fake NHS letters sent to Mr O’Hara, the questionnaire and a photograph showing Kwan in disguise with a wig, beard and moustache.

Ahead of the trial, Kwan had admitted administering a noxious substance, claiming his intention was to cause “mild pain and discomfort”.

Not that Kwan has shown any hint of remorse.

“Even while in prison awaiting trial, his letters to his wife express zero regard for Mr O’Hara’s life but a bitter complaint and resentment that he may be eligible for compensation,” the prosecution barrister added.

“He is plainly disappointed Mr O’Hara may have survived to be eligible for such.”

It is understood that Ms Leung has now sold the property her son was so desperate to get his hands on.

Meaning that, while facing a lengthy jail sentence and with no prospect of ever again working again as a doctor, Kwan’s evil plot could not have gone more wrong.