SINGAPORE: Angered that her adoptive father was refusing to share flat ownership with her after her mother died, a woman bought a chopper and hacked the 67-year-old man to death after he emerged from a shower.
Tan Qiu Yan, 33, was sentenced to 18 years’ jail on Monday (Jul 14) after pleading guilty to culpable homicide not amounting to murder.
The Singaporean woman qualified for the partial defence of diminished responsibility, where the mental state of offenders reduces their responsibility for their criminal act.
This is because she suffered from delusional disorder of a persecutory type, with a background of schizoid personality disorder at the time of the offence.
She was labouring under delusional beliefs against the backdrop of grief related to the death of her adoptive mother, who appeared to be her primary social support, the court heard.
People suffering from persecutory delusions typically hold the false belief that they are being obstructed, conspired against, attacked or harassed.
WHAT HAPPENED
Tan was adopted as a child by Mr Tan Ah Bang and his wife. The family lived in a flat at Block 190A Rivervale Drive in Sengkang.
In 2019, Tan’s adoptive mother was diagnosed with lung cancer. Before she died, she promised Tan that she would leave her share of the flat to her, court documents stated.
After her death in August 2022, her share of the flat automatically passed to Mr Tan, who became the owner of the flat.
During the funeral wake, Tan got into quarrels with her father over her mother’s financial assets and ownership of the flat.
During one quarrel, he got angry and told his daughter that she had to move out of the flat.
She then told her father that her mother had left the flat to her, and not to him, and began crying.
At this, Mr Tan relented and promised to transfer ownership of the whole apartment to his daughter.
However, she did not trust her father and feared that he would eventually have the whole home to himself.
A few days after the funeral wake, she bought a chopper from a supermarket, selecting a larger one that was very sharp, thinking that it would be “more effective” in killing her father.
After the funeral, father and daughter went to a law firm to settle administrative matters, where the lawyers advised the pair to check on the title deed of the flat and to whom it belongs.
Tan helped her father to reset his password for Singpass, the national authentication system for e-services, and used it to check the Housing and Development Board (HDB) records pertaining to the flat.
She discovered that her parents had owned the flat as joint tenants. In October 2022, she called the law firm and updated it about this fact.
She then became aware that her father had become the sole owner of the property after her mother’s death. She panicked and suspected that her father would kick her out of the flat.
On an occasion after this, she asked her father when he was going to the HDB office to add her as the flat’s owner. Her father refused and scolded her for several things, including not telling him that she had received Central Provident Fund money from her mother.
During this quarrel, Tan flung a cup and a jar of peanut butter to the ground. Her father cleaned up the mess and said he would not leave the flat to her when he died, but that he would donate it.
Immediately, she thought about killing him and considered using a pair of scissors on the table. She returned to her bedroom thinking about it, fearing that she would become homeless.
THE DAY OF THE KILLING
On Nov 3, 2022, Tan woke at around 8am and heard her father telling someone on the phone that it was not convenient to talk because his daughter was around.
Thinking that her father was “scheming” to get the flat, she called the law firm requesting to be added as owner of the flat, but was told that she could not.
She continued ruminating on whether to kill her father until lunchtime that day, when she received a card from a hospital signed by doctors offering condolences on her mother’s death. She began crying as she read the card.
After lunch, she returned to her bedroom where she practised using the chopper to slash the air and a banana. She found that the cut was clean and the blade was sharp.
She then checked on her father and found him lying on his front in his bedroom. She considered taking him by surprise, but grew scared because “she had never killed anyone before”, the prosecution said.
She decided to give her father “one last chance”. Later, she went to the toilet where he was scrubbing her work uniform and asked if he was willing to share the flat with her in a 50-50 ownership.
He angrily said that he would not and told her not to bring it up anymore.
At this, Tan made up her mind to kill him. She considered her options before deciding to catch him by surprise in the toilet.
That evening, the father cooked dinner and they ate together. She then waited for him to take a shower.
Once she heard the sound of running water, she removed her glasses so they would not fall or break in the attack and waited outside the toilet holding the chopper.
At 8pm, when her father opened the door, she swung the weapon at him.
The man tried to say something, but she ignored him and hacked at him “at a very fast speed”, aiming for his neck, the court heard.
After she hacked at her father five to 10 times, the man fell backwards, his hand grasping his daughter’s hair.
He landed in a sitting position near the sink and she continued attacking.
She could not tell where the chopper was landing because her father did not release his grip on her hair. He bit her finger, but she did not stop.
Feeling that her father was still alive and holding onto her hair, she hacked at him about 10 more times until he released his grip and was motionless on the floor.
She sat cross-legged facing her father and hacked at him about 30 more times, finally stopping when she got tired.
The entire attack had lasted about 10 minutes, according to her estimate.
She then cleaned up the toilet, threw away her bloodstained clothes, went to listen to music and looked at childhood photos of herself with her parents.
At about 5am on Nov 4, 2022, she began heading to Sengkang Police Station before it occurred to her that the police could come to her instead. She called the police and said that her father had died at home and asked them to head to the flat.
She was arrested later that morning.
THE AFTERMATH
An autopsy certified Mr Tan’s cause of death as bleeding due to incised wounds to the neck. He had suffered numerous deep incised wounds to his neck.
Tan was assessed by the Institute of Mental Health (IMH) and found to be suffering from delusional disorder of a persecutory type, with a background of schizoid personality disorder.
She qualified for the partial defence of diminished responsibility, but she was not of unsound mind at the time of the offence and was fit to plead in court.
The psychiatrist said Tan had limited insight into her condition and that if untreated, her psychosis would be expected to elevate her risk of reoffending, especially if her delusional beliefs extended to other people in her life.
Deputy Public Prosecutors Sheldon Lim and Gladys Lim sought life imprisonment for Tan, the maximum penalty.
Mr Lim said that Tan has not been cured and there is a risk of deterioration of her psychosis if she does not adhere to treatment on a long-term basis.
Tan is an only child with no relatives or caregivers to supervise her, and if she stops taking medication, the consequences would be dire and she would “pose a catastrophic risk to the community at large”, Mr Lim added.
Defence lawyer Daniel Koh asked for five to seven years’ jail instead, saying his client is agreeable to continue taking her medication and had been cooperative in correctional settings.
She was described as being very isolated and tended to keep to herself, but there had been improvement in her hygiene and grooming and she had been observed to relate better to others in general, Mr Koh added.
Speaking on the “ecosystem of inmates being released post-incarceration”, Mr Koh said that Anglican Care Centre is prepared to respond on arrangements when Tan is released.
Tan had also been attended to by a pastor from Prison Fellowship, who was in court showing support for her.
Justice Mavis Chionh found that the case did not fulfil one of three conditions required to impose life imprisonment for culpable homicide not amounting to murder.
She agreed with the defence that Tan did not fulfil the second criterion, which requires determination of whether the accused is a person of unstable character likely to commit such offences in future.
Justice Chionh said it was material that Tan did not have a history of offending, or unstable or violent behaviour.
She pointed to an IMH report, which said a major factor in Tan’s mental state at the time was the grief from losing her mother, whose death from cancer was “devastatingly experienced” by Tan.
The judge also found it material that an IMH psychiatrist noted in a January 2025 report that Tan “appeared to have gained at least partial insight into her condition”.
Justice Chionh said Tan’s fears of being left homeless seemed to have been fortified by a number of unfortunate encounters with her father.
“That the deceased, who clearly doted on the accused, likely spoke impulsively and that he might eventually have acceded to her demands is besides the point,” the judge added.
“The point is that her conduct was founded on fact, not fantasy or fiction, although evidently the violence she inflicted … was entirely out of proportion to the perceived threat.”
Nonetheless, Justice Chionh said it was “a shocking and brutal act of violence” by the accused against her adoptive father.
Photos in court documents “attest vividly to the significant ferocity” of Tan’s attack, the judge added.
“While armed with a sharp weapon, she inflicted horrific and ultimately fatal injuries on a man who had cared for her for many years.”
She considered 18 years appropriate for the case, while weighing the mitigating factors.
Tan stood silently through most of the hearing, listening to a Mandarin interpreter with her eyes closed and remaining expressionless.
