Dec 5: Sarina Yusoff, the distraught mother of Zayn Rayyan Abdul Mattin, files a police report at 6.36pm when her six-year-old son goes missing.
She realised her son, who is autistic, was missing while climbing the stairs up to their third-floor apartment unit in Damansara Damai after picking him up from school.
Dec 6: A massive search and rescue operation is launched comprising multi-agencies, including the neighbourhood watch in Idaman Apartment.
At least 40 police personnel, aided by more than 60 residents, also conducted a door-to-door search covering 2,484 residential units at the 18-block apartment.
K9 sniffer dogs were also roped in.
Dec 6: A resident aiding the search finds Zayn Rayyan's remains in the shallow waters of the riverbank about 9.30pm.
The boy was fully clothed in the school uniform he was last seen in. His body was found was just 200-metres from where he had been last spotted by his mother.
Dec 7: Zayn Rayyan's remains are brought to the Sungai Buloh Hospital for a post-mortem examination.
The case is classified as sudden death, pending the results.
Dec 7: Police believe that Zayn Rayyan was killed elsewhere before his body was dumped along the banks of a stream in Damansara Damai.
They also believe that he died of strangulation.
Dec 7: Zayn Rayyan's remains are released from the Sungai Buloh Hospital's Forensic Department at 5.55pm after the post-mortem examination concludes.
His body is later buried at the Seksyen 9 Muslim cemetery in Kota Damansara.