Mother's partner was injected with poison disguised as a vaccine by a British doctor, who later admitted to attempted murder.

On Monday, a British doctor confessed to attempting to murder his mother's partner by pretending to be a nurse and administering the victim with poison, which he disguised as a Covid-19 vaccine. Thomas Kwan, 53, wore a wig, facial hair, and a medical mask while carrying out the attack in Newcastle, England, more than three hours north of London.

According to Reuters, Kwan arranged a fake medical appointment with O'Hara by sending him bogus letters stating that he needed a Covid vaccination, said Northumbria police.

Kwan wore a disguise to avoid being recognized by his mother and O'Hara, both in their 70s, who were believed to be nurses.

O'Hara experienced a skin condition at the injection site and became seriously ill shortly after, police stated. He went to his general practitioner and was subsequently admitted to the hospital. Upon arrival, he presented hospital staff with fake injection letters.

O'Hara sustained life-changing injuries after undergoing skin grafts to repair the extensive damage caused by a fatal flesh-eating bacterial infection called necrotizing fasciitis. The British Crown Prosecution Service stated that O'Hara was injected with an as-yet unconfirmed toxin.

Kwan allegedly put on fake license plates on his car and drove to O'Hara's home, where the poisonous injection occurred. According to prosecutor Peter Makepeace, Kwan's motive may have been related to his mother's will, which stated that her partner would inherit her home if she died and that O'Hara was still alive.

Kwan's home was searched by police, who discovered on his computer files related to using poisons to kill a person, including a "poisoner's handbook."

On the first day of the trial, Makepeace informed jurors that Mr. Kwan's extensive knowledge of and research into poisons were used to execute his plan.

Kwan initially pleaded not guilty, but pleaded guilty Monday to the attempted murder charge.

He remains in custody until his sentencing is held at a later date.

"Kwan's attempt at murder was proven through evidence and he has now admitted to it, according to Detective Chief Inspector Jason Henry of Northumbria Police. Although nothing can undo the harm caused to his victim, it is hoped that Kwan's conviction will aid them in healing."