LONDON — A UK physician who was unhappy about his inheritance has received a 31-year prison sentence for attempting to poison his mother’s partner, using a substance he disguised as a COVID-19 vaccine. Dr. Thomas Kwan, age 53, posed as a home health worker to inject Patrick O’Hara with a toxic substance known for its severe effects on the body. Kwan was motivated by a desire to inherit his mother’s property, believing O’Hara was a barrier to that goal.

In court, Justice Christina Lambert characterized Kwan’s scheme as brazen, stating that he nearly succeeded in his plot to murder someone in broad daylight. The judge emphasized Kwan’s fixation on financial gain, particularly regarding the inheritance he felt entitled to.

Kwan entered a guilty plea for attempted murder last month at the Newcastle Crown Court. O’Hara, age 72, managed to survive the ordeal after spending several weeks in intensive care and undergoing surgery to remove affected tissue from his arm, which was critical in preventing the spread of the dangerous condition known as necrotizing fasciitis.

The experience left O’Hara emotionally and physically traumatized, and he described himself as “a shell of an individual.” Following the incident, O’Hara and Kwan’s mother, Jenny Leung, ended their relationship.

The investigation into Kwan was aided by security camera footage that captured his actions. Authorities discovered that he had devised a complex plan, which included sending fraudulent communications featuring National Health Service branding and links for scheduling a COVID booster shot. To carry out his plan, Kwan donned full protective gear, including tinted glasses and a surgical mask, and arrived at the appointment in January driving a vehicle with false license plates.

Kwan’s obsession with poisons was highlighted by the judge, who noted that he used iodomethane—a toxic substance usually found in pesticides—believing it would evade detection by medical professionals. During a raid on his residence, police uncovered additional dangerous substances, including arsenic, liquid mercury, and castor beans, which can be processed into the lethal agent ricin. Kwan’s computer contained instructions on how to manufacture ricin as well.

His motivations stemmed from a distressed relationship with his mother and dissatisfaction over the distribution of his father’s estate after his passing. He discovered a clause in his mother’s will that permitted O’Hara to reside in her home if she passed away first, which fueled his resentment. The judge pointed out that Kwan’s anger and bitterness directed at both his mother and O’Hara revolved around issues of inheritance and the money he believed he was owed.

In the wake of the sentencing, O’Hara expressed satisfaction that justice had been served.