Leedon Park double murders

Originally from Indonesia, Osman bin Ali lost his father at age two and therefore, Osman and his mother immigrated to Singapore, where she remarried and had more children with her second husband. Osman was sent to live with a relative due to not enough accommodation for a large number of the children. Osman went to primary school at age seven but dropped out after two months, as a result of a speech defect. After which, Osman underwent treatment for his speech problems, which later improved, although he never resumed his studies. Osman later worked as a gardener at age 15, and eventually began working as the gardener for the Thomas family at their Leedon Park bungalow, a job which lasted ten years before he committed the double murder.[12]

On 14 September 1971, after a five-day preliminary hearing in February of the same year,[13][14] 32-year-old Osman bin Ali officially stood trial at the High Court for two charges of murdering Wu Tee and Tan Tai Hin. Prominent lawyer and opposition politician David Saul Marshall represented Osman in his trial while Isaac Paul Ratnam was the trial prosecutor. The case was heard by two judges Choor Singh and D C D'Cotta.[15]

The pathologist Chao Tzee Cheng came to court to present his autopsy findings to the court. He testified that based on the manner of how the victims were killed, it was likely that the killer had caught both Tan and Wu by surprise from behind and strangled them, considering that there were no signs of a struggle and judging from the duration of the strangulation, the death of the victims occurred within a minute.[16] Wu's daughter Low Ek Meng came to court to testify that before the double murders of her mother and Tan, she last seen her mother going to wash the clothes and even had a friendly conversation with Osman, and last saw Tan returning from the market before proceeding to wash his clothes. After this, she heard Tan saying "apa macham" in a frightened tone, and this led to her coming outside and discovering her mother's body.[17] Osman's cousin Naim bin Ali also told the court that shortly after the murders, Osman had gone to his house to tell him he killed two people due to a misunderstanding before he drunk some wine and went to the police station.[18]

Osman later elected to give his evidence, and he denied that he had intentionally used the rope to strangle the victims.[19] His main defence was diminished responsibility. Osman told the court that he suffered from head injuries due to a traffic accident ten years ago, and hence he became easily prone to anger and fought with his sisters and step-brothers.[20] Osman testified that on the day of the murders, he had an argument with Wu and it caused him to, in a fit of anger, use a rope to assault and strangle Wu,[21] and later, he attacked Tan, who happened to chance upon the killing and he therefore strangled Tan, and subsequently hung his body to give the impression that Tan had committed suicide by hanging.[22] Osman added that after the killings, he was plagued with nightmares of his victims.[23]

David Marshall argued that based on psychiatric opinion by defence psychiatrist Wong Yip Chong, Osman had a low IQ of 89, and with subnormal intelligence and mental defects, Osman was prone to extreme and impulsive reactions even in the face of the most minor of provocations, leading to him reacting abnormally and impulsively at the time of the killings. Mershall sought to argue that these above factors, be it mental or environmental, had been sufficient to prove that Osman was suffering from an abnormality of the mind and therefore, he should not be guilty of murder but of manslaughter.[24][25]

However, Dr F Y Long, the prosecution's psychiatric expert, testified that despite his low IQ, Osman was observed to be spontaneous, relevant, clear of speech, rational and co-operative. Dr Long said that Osman was also able to have normal social interactions, and cognitive functioning, persistently tried to solve his problems, and had no problems with daily functioning. This showed that Osman was not suffering from impaired mental responsibility at the time of the offences, and had full awareness of the magnitude of his actions, corroborating the prosecution's contention that Osman had intentionally committed the murders with the premeditation to kill both Tan and Wu, without the need to prove any motive behind the killings.[26][27][28]

On 28 September 1971, the trial judges Choor Singh and D C D'Cotta delivered their verdict. In the judgement, Justice Singh, who pronounced the verdict, stated that the prosecution had proven its case beyond a reasonable doubt, accepting the evidence that Osman was not suffering from any abnormality of the mind when he killed both Tan Tai Hin and Wu Tee, and hence, they found 32-year-old Osman bin Ali guilty of committing the premeditated murders of Tan and Wu, and sentenced him to death for two counts of murder.[29][30]

Reportedly, Osman's 48-year-old mother Che Maria binte Supri, who had been fasting and praying for her son, was so distraught at the death sentence that she actually fainted, and had to be brought out and laid on a bench until she regained consciousness. Osman's mother, one of his younger brothers Salim and one of Osman's sisters wept at the verdict.[31][32]