SINGAPORE: A man who was suffering from schizophrenia and under the influence of drugs allegedly strangled his father and inflicted multiple blows on his face five years ago, causing his death.

Tan Kok Meng, 46, went to trial on Tuesday (Aug 11) for one count of murdering his 75-year-old father in their flat in November 2015.

The prosecution is seeking for Tan to be kept in safe custody pending an order of the law minister for him to be confined in a psychiatric institution, prison or suitable place of safe custody at the President's pleasure.

This is an uncommon situation, and both the prosecution and defence agree that there is evidence that Tan was likely of unsound mind at the time of the offence. 

However, the prosecution will have to prove that Tan committed the alleged acts, and that the acts constituted an offence. 

If the court finds that this is so, and that he was of unsound mind, it may direct Tan to be kept in safe custody and later confined in a psychiatric institution or other suitable places.

WHAT HAPPENED THAT DAY

The court heard that Tan was unemployed and lived with his father and mother, named only as Madam Toh in court documents, in a flat in eastern Singapore.

On Nov 13, 2015, Mdm Toh noted that her son was not his usual self, and had been looking "dazed" for the past two days, pacing up and down the flat.

As she noted that he was not in a good state, she did not want him to leave the flat, and kept the keys from him, asking her husband to follow suit.

She left her husband alone with Tan in the flat at about 2.30pm, said the prosecutors in their opening statement.

About three hours later, Mdm Toh returned to the flat, noticing that the main door was open while the metal gate was padlocked.

When she entered the flat, she saw her husband breathing heavily and lying supine in a pool of blood, while her son sat on the sofa.

When she asked him what happened, he did not respond.

Mdm Toh left to get help from her neighbours before returning to the flat. The neighbours saw blood on Tan's hands and body and the victim lying on the floor gasping for air.

Mdm Toh shouted at Tan, asking why he had killed the victim. Tan walked towards his father, sat on his abdomen and placed his hands just below his throat, said the prosecution.

Mdm Toh pulled her son away from her husband, and a team of paramedics arrived soon after. Tan's brother had called the police.

Paramedic Ms Zaneta Lee asked Tan if he was "OK", as she noticed that his body and clothing were covered with dried blood. However, Tan was dazed and did not reply.

Ms Lee assessed that the victim had sustained a severe head injury, with swelling and bruising of both eyes. She inferred that his airway was obstructed as he was making "snoring-like" sounds, and inserted a device to clear the obstruction.

Tan suddenly stood up from the sofa and sat on his father's abdominal region, placing both hands on his father's neck and throttling him.

Ms Lee testified on Tuesday that the victim was unresponsive when she entered the flat with her colleague. Tan was sitting on a sofa and was covered in dried blood around his upper body, she said.

Suddenly, Tan went to his father and placed his hands one above the other, strangling his throat, said Ms Lee. 

Her colleague was "shocked" and "just staring at the accused", unsure of what to do.

Ms Lee shouted at Tan, asking him to move away, but Tan ignored her and continued strangling Tan, while mumbling "I want him to die" in Mandarin.

Shortly after, police officers arrived and arrested Tan. He told an officer that he had had a strained relationship with his father for some time, and said he had hit his father with his bare hand.

He told another officer that he had punched his father, and that his father had called him a "good for nothing". After this, he purportedly punched his father in his face "continuously".

He told a third officer that he had punched and slapped the face of "someone" with all his might, the prosecutors said.

CAUSE OF DEATH AND PSYCHIATRIC FINDINGS

The victim later died, and his cause of death was certified as "strangulation and aspiration of blood", with a forensic pathologist observing extensive bruising and bleeding underneath the bruises over the man's face, chest and upper limbs.

Laryngeal fractures and severe bleeding were also found on the man's neck. The aspiration or breathing of blood was likely to be from the deep laceration of the man's tongue, which is consistent with being punched in the face.

Tan was assessed at the Institute of Mental Health (IMH) to be suffering from schizophrenia, a major psychotic mental illness, around the time of the offence. 

On the day of the offence, he had been "unstable", displaying symptoms such as pacing around and muttering to himself, and was "probably of unsound mind".

A second psychiatrist examined Tan and agreed that Tan was probably of unsound mind at the time of the offence. In addition to suffering from schizophrenia, Tan was in a state of "acute drug intoxication due to the consumption of methamphetamine" at the time of the offence, said the IMH associate consultant.

Dr Cheow Enquan will testify in the trial that it was "very likely that the accused was experiencing severe psychiatric symptoms with disorganised behavior at the material time which could have been due to schizophrenia and further exacerbated by his drug use".

Tan was certified to be of unsound mind and incapable of making his defence in March 2016. Court proceedings were stayed and he was confined at Changi Medical Complex.

However, he was subsequently certified to be capable of making his defence and the stay on court proceedings was lifted in September last year.

Tan is defended by lawyers Favian Kang and Nichol Yeo. The prosecutors will lead evidence from 48 witnesses, including paramedics, police officers and forensic psychiatrists to prove its case.

If successful, it will be asking for an order under Section 252 of the Criminal Procedure Code to be made to keep Tan in safe custody.

Those who are confined under this section may be regularly reviewed by independent experts of a psychiatric institution at least once every six months.

They may be discharged on the law minister's order if a review deems them fit for it, or if there is sufficient social support and assurance that the person will be cared for and will not injure himself or others.

The trial continues.