In a case that left the nation stunned, 13-year-old schoolgirl Nong Kaem was raped and murdered by an employee of the State Railway of Thailand on an overnight train in early July.
Taken away: Wanchai Saengkhao, 22, was convicted for the murder of Nong Kaem.
Nong Kaem, a Mathayom 2 student at Satrinonthaburi School in Nonthaburi, was missing when the No 174 sleeper train from Nakhon Si Thammarat arrived in Bangkok on July 6.
Her disappearance was a total mystery to all and there seemed no plausible reason.
An investigation was launched and it only began to unravel when Pol Maj Gen Thitirat Nonghanphitak — the deputy chief of the Central Investigation Bureau who at that time was deputy chief of the Metropolitan Police Bureau — stepped in.
Commuters and train staff were closely interrogated and police quickly began to realise that the girl's disappearance was intentional and likely to be connected to a carriage worker.
There was evidence to suggest foul play but not a likely culprit.
Then investigators started finding little clues that gave them a trail to follow. Among her personal effects left on the train, a major item was missing: her iPhone. Police scoured the second-hand mobile phone shops and found it in Bangkok's Si Yan area.
Questioning of the shop owner led to the arrest of two suspects, Wanchai "Game" Saengkhao, a 21-year-old bed-sheet changer on the train, and Natthakon "Nueng" Chamnan, a 19-year-old train cleaner.
Wanchai confessed to raping and murdering Nong Kaem. He said he dumped the girl's body along with her blood-stained clothing and a bed sheet out of the carriage window to conceal his crime. On Sept 30, Wanchai was sentenced to death for rape and murder. Natthakon was sentenced to four years as an accomplice.