Mentally ill cleaner pleads guilty to culpable homicide

SINGAPORE — The day after he was scolded by his colleague at work, a cleaner suffering from paranoid schizophrenia started seeing and hearing things.

Pua Kok Heng thought he saw Goh Ah Moy’s apparition floating into his flat, challenging him to take a knife to their workplace at Jurong East MRT Station.

When the same image appeared in his mind the following day, the 57-year-old took two knives to the MRT station and plunged one into Goh’s chest, killing the 62-year-old woman.

Pua, who is also known as Tiger, yesterday pleaded guilty to culpable homicide not amounting to murder, with his lawyer pleading for a 20-year jail term. Prosecutors, however, called for life imprisonment, saying Pua had no family support for his psychiatric condition and had a high risk of reoffending.

The court heard that two days before Pua stabbed Goh, she had scolded him for using her cleaning equipment and dirtying her mops and pails.

When Pua woke up the next day, he saw Goh’s apparition in his rental flat, claiming to have given birth to him and saying that she wanted to teach him a lesson. He was also challenged to take a knife to their workplace. The image disappeared soon after, but the apparition’s words remained in his mind.

“He could not bear hearing the voice and just wanted to follow the instructions of the image and the voice,” said Deputy Public Prosecutor Jasmine Chin-Sabado.

Later that day, Pua confronted Goh at work with a knife tucked into the waistband of his shorts, but their supervisor intervened.

On the following day, Nov 24, 2011, Pua again saw Goh’s apparition flying through his kitchen window and making accusations against him in Hokkien.

Angered, he headed for Jurong East MRT Station — although he was not scheduled to work that day — with two knives tucked into his waistband.

When he found Goh at the rear of the public lift at the MRT station, Pua stabbed her once on the left side of her chest and punctured her heart. She died later that day.

The court heard that Pua was diagnosed with paranoid schizophrenia in 1995. On the day of the offence, he had suffered a relapse, said an Institute of Mental Health psychiatrist.

DPP Chin-Sabado yesterday said the psychiatrist had found Pua to be suffering from persecutory delusions that were “significantly causally linked” to the offence. She added that Pua had stopped taking his psychiatric medication when he committed the offence because it had affected his ability to work.

The prosecutor argued for Pua to be put away for life, but defence counsel Josephus Tan said in mitigation that his client was “labouring under the considerable influence of his mental disorder”.

The lawyer also noted Pua’s age and remorse, claiming that his client had been “faithfully adhering” to medical treatment while he was in remand the past two years.

The prison psychiatrist had found that Pua did not pose a risk to society or himself in his present mental state, Mr Tan added.

Justice Lee Seiu Kin adjourned the hearing, pending further reports on whether Pua would require medical treatment for life and whether he would be likely to default on his treatment.