A 67-year-old man who died following a spat with his son had likely sustained his injuries over a "considerable amount of time" and suffered "a significant amount of force" to his neck.
His son, Mark Tan Peng Liat, 30, a businessman, has been charged with culpable homicide not amounting to murder for his death. Tan appeared in court yesterday for the third day of his trial.
His father had 31 external injuries, an autopsy found, and these were likely inflicted over a "considerable amount of time". Among his internal injuries was a fracture of the thyroid cartilage. He had bruises and abrasions as well. All these were believed to be fresh injuries.
A polo shirt with the older man's blood was found in Tan's laundry basket in his bedroom, the court heard.
Tan was said to have put his father, Mr Tan Kok Keng, in a headlock and chokehold after a quarrel at their West Coast Rise home on Feb 10 last year. The senior Mr Tan was pronounced dead an hour after he was taken to the National University Hospital.
Taking the stand yesterday were Assistant Superintendent Tan Boon Kok, senior investigation officer for the case, and Dr Lee Chin Thye, a forensic pathologist with the Health Sciences Authority who did the autopsy.
Injuries on both sides of Mr Tan's neck "indicate that a significant amount of force was applied" to it, said Dr Lee. He added: "Many of these injuries are over vulnerable areas, exposed areas, prominent areas, where injuries can be sustained when one is struggling - either knocking against objects, against parts of the wall, or on the floor."
They were also on various parts of the body and unlikely to have been suffered over a short period of time.
As the list of injuries was read, Tan stared straight ahead, closing his eyes halfway through.
ASP Tan said yesterday that bloodstains were found in the toilet of the master bedroom on the day of the incident. This was the bedroom where the senior Mr Tan was found motionless. Tan's bermudas were stained with both his and his father's blood.
The court heard that a psychiatric evaluation done by Dr Jaydip Sarkar also showed that Tan did not suffer from any mental disorder or intellectual disability. He was not of unsound mind and did not have any clinical disorder.
The Straits Times understands that the accused's position is that the elder man's death was accidental, and that he was trying to restrain his father who had become violent. The late Mr Tan also suffered from hypertensive heart disease, which was discovered only during the autopsy.
Dr Lee said that while the main cause of death is believed to be a "manual compression of the neck", heart disease was likely a contributory factor that hastened his death.
In July, Tan's paternal aunt, Madam Tan Hoon Choo, 72, recounted in court how the elder Mr Tan's maid had gone to her house "hysterical" and crying. Ms Sumarti Dwi Ambarwati has since returned to Indonesia and could not be contacted.
Tan had appeared pale and bewildered when Madam Tan went to the house. If found guilty of culpable homicide, he could be jailed for up to 10 years, fined or caned.