[2] On 4 May 1991, Delia Mamaril Maga[3] (born on 6 October 1955, in Tarlac), a 34-year-old Filipino domestic worker, was found strangled to death in a five bedroom apartment on the ninth floor of HDB Block 147 on Gangsa Road in Bukit Panjang.

[4] Singaporean police investigating the crime scene found no signs of a struggle or any ransacking of the flat, which combined with the fact the front door grille was locked when the owners returned home suggested that Maga knew her killer and granted them entry to the apartment.

This fact raised the possibility that Contemplacion killed Huang and Maga to prevent her being identified, however the life of the two-year-old girl was spared as she was unable to speak due to her young age.

[11] That evening, investigating officers brought Contemplacion and the interpreter to the crime scene on Gangsa Road, where she described to the detectives how she was admitted to the apartment by Maga and what happened inside on the day of the murders.

In her opening speech, Deputy Public Prosecutor Kamala Ponnampalam described how the victim's dead bodies were discovered by Huang's parents, who after failing to resuscitate Nicholas then called the police.

[14] Testimony by forensic pathologist Doctor Wee Keng Poh revealed that Maga died from asphyxia due to strangulation and Huang's death had been caused by drowning.

According to the expert witness, another person had used an elastic cord wound around Maga's neck to apply moderate force for approximately 5 minutes, while the immersion of a young child's face in water for a similar time would cause them to drown.

[15] Contemplacion's lawyer Ng Wing Cheong challenged the admissibility of five statements[16] she gave to police after her arrest, asserting that they were made under duress while she was fatigued after hours of intensive questioning by detectives.

[20] At the close of the prosecution's case, Justice T.S Sinnathuray declared that prima facie evidence had been established against the accused and called on Contemplacion to make her defence against the charge of murdering Della Maga and Nicholas Huang.

When Justice T.S Sinnathuray thereafter invited the defence legal team to rebut the accusations against Contemplacion, her lead counsel Ng Wing Cheong informed the court that in light of his client's refusal to give evidence he had decided not to call any witnesses or make any submissions on her behalf either.

[20] On the afternoon of 29 January 1993, Flor Contemplacion was found guilty as charged and sentenced to death for the murder of Delia Mamaril Maga and Nicholas Huang,[12][20] in accordance with Section 302 of the Penal Code of Singapore.

An affidavit containing observations from Gleneagles Hospital consultant psychiatrist Doctor Terence Burke, who had studied the case in detail and since examined Contemplacion personally, was requested to be submitted by Singh.

[24] Testimony from Doctor Terence Burke asserted that Contemplacion suffered from a form of epilepsy known as a partial complex seizure, which was a mental illness that significantly impaired her responsibility for her actions on the day in question.

Raj argued that Contemplacion was simply suffering from a migraine on the day of the murders, adding that she had been examined previously by the consultant psychiatrist of Changi Prison hospital, Doctor Chan Khim Yew, and was determined to have no abnormality of the mind that would impair her mental reasoning abilities.

[23] The court's judgement noted that the comprehensiveness of Contemplacion's actions in the apartment, such as using two different methods to silently kill each victim and locking the youngest child in a bedroom to prevent the sound of her crying alerting any bystanders, coupled with her ability to remember the events of that day in clear detail, proved that she was not suffering from a partial complex seizure during the time of the murders.

The fact that both women had argued over the size of the package Maga refused to take with her to the Philippines on Contemplacion's behalf was attributed as a more likely motive for the fatal attack, according to the judge.

The judge likewise dismissed claims that Contemplacion was unintelligent, as having witnessed her nimble performance during cross examination over several days he considered her a wilful and cunning person.

Defence lawyer Sant Singh argued that while the circumstances of the double murder she was convicted of were not in dispute, the original trial judge had erred in ruling the symptoms described by Contemplacion as a mild migraine rather than temporal lobe epilepsy, which was a core element in her pleading guilty by diminished responsibility.

Although Doctor Chan Khim Yew had previously raised the fact that Contemplacion had not exhibited any unusual behaviour to her employers during the 3 years she worked for them, the defence asserted that they would only be able to observe her during evenings and weekends and therefore never had the chance to properly scrutinize her psychological condition.

[26] The Appeal Court judges rejected all defence arguments, highlighting how Doctor Chan Khim Yew had observed Contemplacion's behaviour over 18 months while she was on remand and had ample time to diagnose any psychiatric issues.

The court also gave credence to her faultless work history as evidence she was not suffering from any serious illness, as she was trusted to look after young children while living in the same house as her employers, who would have easily spotted Contemplacion having epileptic fits on a near monthly basis as she claimed.

The original trial judge was also deemed to have correctly considered the calculated shrewdness of Contemplacion's actions inside the flat on the day of the murders as evidence of a lack of mental abnormality on her part, as well as her alert and quick thinking performance while under cross examination being proof she was in fact a cunning and intelligent person.

[28] In the days leading up to the scheduled execution, Filipina maid Emilia Frenilla, who had previously worked for Huang's uncle, submitted a sworn statement to the Singaporean Embassy in Manila, claiming:[29][28][30] However, after an investigation Singaporean authorities disregarded the new evidence, citing factual errors such as:[32] Also, the fact that after her arrest Contemplacion revealed to police the location of luxury items she had stolen from Maga provided strong circumstantial evidence that she was linked to the murders.

Shortly after midnight on the morning of the scheduled execution, Filipina citizen Virginia Custodio Parumog, who in 1992 had shared a prison cell with Contemplacion in Changi Prison while serving a custodial sentence for prostitution, returned to Singapore via commercial airline[33][34] and then attempted to submit an affidavit to Singaporean authorities containing claims such as:[35] Shortly afterwards, the Ministry of Home Affairs released a communiqué denying all allegations, stating:[35] Sister Gerard Fernandez (a Good Shepherd nun) accompanied Contemplacion on her final walk to the gallows, where they both sang the hymn Amazing Grace.

[41] The Philippine Embassy in Singapore in particular was heavily criticised, since it did little to help Contemplacion during the two years she was on remand, apart from delivering food and books to her in prison, and did not even have a consular representative as an observer in court throughout her trial.

[18] The former Embassy labour attache Reynaldo Catapang later confirmed that they did not hire a private lawyer to represent Contemplacion and allowed the Singaporean authorities to appoint a public defender instead, nor did they keep any records of the legal proceedings or transcripts of the court case itself.

[44] It was also revealed that Contemplacion was allowed to have at least nine private consultations with Philippine Embassy officials without Singaporean authorities being present, yet she did not withdraw her original confession or change any aspect of her testimony at any of these meetings.

[57] The finished report recommended that the case be reopened, after gathering new testimony, in addition to earlier claims made by Parumog and Frenilla, such as:[58] The Singaporean government described the findings as "totally absurd" and based on uncorroborated hearsay testimonies of individuals who did not witness the crime itself,[63] and later released its own point by point rebuttal of the findings, such as:[58] On 20 October 2005, three of Contemplacion's sons, Sandrex and twins Jun-Jun and Joel, were arrested for drug trafficking after a buy-bust sting operation by the San Pablo City police, where an undercover officer bought ₱3,000 worth of methamphetamine from the brothers.