Zainuzzaman Mohamad Jasadi was born around 1967 in Lenggeng, Negeri Sembilan, Malaysia. He lived in close proximity to his eventual victims in Kampung Seri Budiman, Kuala Lumpur. At the time of the crime, he was 24 years old and unemployed. Reports also indicated that he was struggling with drug addiction.

Very little is publicly known about Zainuzzaman’s early life, family background, or education. However, his actions and behavior leading up to the crime suggested instability and possibly obsessive tendencies. Some speculations even arose that he had developed an unreciprocated infatuation with his young victim, though this was never fully substantiated in court. His proximity to the victims and lack of stable employment made him a suspect early in the investigation. Police later revealed that he had previously attempted to sell jewelry known to belong to one of the victims.

On 22 June 1991, the serene Kuala Lumpur neighborhood of Kampung Seri Budiman was rocked by a double murder that sent shockwaves across Malaysia. Twelve-year-old Intan Yusniza Mohamad Yunos, a beloved child TV host on RTM’s Angkasapuri Children's Club, and her 56-year-old foster mother, Haniza Ismail, were found brutally bludgeoned to death in their terrace home.

It was a neighbor who first discovered the horrifying scene while cleaning his car. He had seen the mother and daughter return the previous night in a van. Inside the home, Intan and Haniza were found lying lifeless in pools of blood. Jewelry and cash were missing, pointing toward a robbery gone violent.

Autopsies revealed devastating trauma: Intan was hit at least five times with a blunt object, causing a shattered skull. Haniza was struck twice, resulting in a fatal brain hemorrhage. Both women had been attacked while asleep. Reports at the time suggested possible sexual assault, but this remained unconfirmed publicly.

The case gripped the nation. Rewards were offered by newspapers, city hall, and even local residents to help identify the killer. On 1 July 1991, the Royal Malaysia Police arrested Zainuzzaman Mohamad Jasadi, a 24-year-old unemployed neighbor and known drug addict. He was apprehended in Lenggeng, Negeri Sembilan and brought back to Kuala Lumpur for questioning.

Police recovered several stolen items, including gold chains and bracelets. One chain, engraved with “Intan,” was traced back to the child victim. Witnesses also placed Zainuzzaman at the scene. A local butcher testified that Zainuzzaman sold him the chain after the murder. A neighborhood youth picked him out from a police lineup, strengthening the case against him.

Initially, Zainuzzaman confessed to the murders, apologizing to the police. However, during his trial at the Kuala Lumpur High Court in August 1992, he retracted the confession, claiming he had been beaten into compliance. The judge eventually ruled the confession inadmissible.

The court proceedings were split into two charges—one for each victim. A seven-member jury acquitted him of murdering Haniza, with a 5-2 majority deciding there was insufficient evidence. But the case for Intan’s murder was stronger. The court found that he had broken into the house, attacked Intan with a blunt iron pipe, and stole valuable items.

The prosecution, led by Idrus Harun, argued convincingly that the location and severity of Intan’s injuries showed a clear intent to kill. On 17 August 1992, the jury found Zainuzzaman guilty of murdering Intan by a 6-1 vote. Justice Mokhtar Sidin upheld the decision and sentenced him to death by hanging.

Zainuzzaman appealed the decision, first to the Court of Appeal, and later to the Federal Court. On 30 September 1997, both appeals were rejected. Amnesty International issued a public plea for clemency, but the Malaysian government stood firm. Zainuzzaman submitted a final petition for a royal pardon to the Yang di-Pertuan Agong, but this too was denied.

On 5 October 2001, after more than a decade on death row, Zainuzzaman Mohamad Jasadi was hanged in Kajang Prison.