On the evening of 1 March 2006, two-year-old Nurasyura binte Mohamed Fauzi, known as Nonoi, went missing from her step-grandfather's flat at Block 62, Circuit Road, Singapore. A widely publicized search involving family, neighbours, and police followed. Three days later, on 4 March, her stepfather, 29-year-old Mohammed Ali bin Johari, confessed to his wife and mother-in-law that Nonoi was dead, saying he had immersed her in a pail of water. He then turned himself in at Bedok Police Station and led police to the Aljunied Flyover along the Pan Island Expressway, where her body was found. He was charged with murder on 7 March 2006 and remanded for psychiatric evaluation.
An autopsy conducted by consultant forensic pathologist Dr Gilbert Lau found injuries to Nonoi's genitals consistent with sexual assault and lungs consistent with drowning, though he could not fully ascertain the definitive cause of death, noting two alternative possibilities (seizure or abnormal heart rhythm) alongside drowning as the most probable cause.
At trial in the High Court before Justice Kan Ting Chiu, which ran intermittently from April to August 2007, Mohammed Ali maintained he had accidentally drowned Nonoi while trying to stop her crying and denied raping her. The prosecution argued he had sexually assaulted her and killed her to cover up the crime, presenting phone records that contradicted his claim of being distracted by a call during the fatal immersion. Psychiatric evidence described Mohammed Ali as a drug user with a low IQ and a history of using Nonoi as cover to avoid detection by narcotics officers. Medical witnesses testified about a prior childhood seizure-related hospitalization and inconclusive genetic findings regarding cardiac arrhythmia risk. On 31 August 2007, Justice Kan found Mohammed Ali guilty of murder and sentenced him to death, ruling that the immersions were intentional and that the evidence did not support the alternative causes of death, while declining to rule on the sexual assault allegation since it was not a formal charge.
Mohammed Ali appealed to the Court of Appeal of Singapore. On 22 April 2008, the three-judge panel dismissed his appeal, upheld the murder conviction and death sentence, rejected a defence of sudden and grave provocation, and additionally found — despite no formal rape charge — that he was responsible for Nonoi's sexual injuries. A clemency appeal to the President of Singapore was also turned down. Mohammed Ali was hanged at Changi Prison on 19 December 2008 and was buried at Lim Chu Kang Muslim Cemetery, reportedly requesting to be buried near Nonoi.
The case received sustained media attention in Singapore, was re-enacted in a 2009 episode of the television programme Crimewatch, and was later featured in a 2015 Straits Times publication on major Singapore crimes. It has subsequently been cited in Singapore public discourse, including in Parliament, in connection with child-abuse cases and debates over the mandatory death penalty for drug trafficking.