Fang Gao San, 56, who was yesterday sentenced to life imprisonment for culpable homicide, suffered from paranoid schizophrenia and delusions.
He claimed to hear voices and detect smells when he believed he was being "attacked" by charms that others had put on him.
Fang was first taken to the Institute of Mental Health (IMH) in May 2003 when he was arrested by the police after praying loudly outside his flat and behaving in an aggressive manner.
Since then, the jobless man was admitted to be stabilised whenever he had a psychotic episode. The longest he spent at the institution was over five months, between August 2007 and January 2008.
In a medical report, senior consultant psychiatrist Stephen Phang described Fang's records as amounting to "two thick volumes".
He would throw away prescribed medication and often missed follow-up treatment sessions.
During his first admission to IMH, it emerged that he had been suffering from mental illnesses for several years, hearing voices and believing that others were out to harm him through "black magic".
He constantly believed that he was under attack by someone who had put a charm on him and that he was being gossiped about. Initially known as Tan Whai Soon, he changed his name in a bid to reverse his fortunes.
Fang's only regular contact with his family was with his younger sister, who revealed that he had an intense obsession with religion, often chanting and frequenting temples.
In his youth, he had even threatened to kill his brother with a knife.
The illness also led him to believe that others were trying to poison him, and he would repeatedly wash or re-cook food to ensure it was safe.
He even bathed in vinegar, which he believed would rid his body of toxins that others were using to harm him.
There were also frequent altercations with his neighbours because Fang regularly wet the corridor outside his one-room rental flat in Redhill.
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