Alleged rapist and murder Wanchai Saengkhao, 22-year-old, and Natthakon Chamnan, 19, who allegedly abetted his crime, arrived at the Prachuap Khiri Khan province courthouse late and avoiding eye contact with the media. Family members of the dead girl wore black t-shirts with messages calling for the death penalty for rapists.
Evidence and witnesses' accounts, as well as the confession of Mr Wanchai were examined at the court. Both had been indicted for the July 9 incident on July 16.
Mr Wanchai's relatives had visited him at Prachuap Khiri Khan prison on Monday and did not appear in court Tuesday. The mother of Mr Natthakon, who also worked at the State Railway of Thailand, said she did not believe her son had conspired in the crime and that she was seeking justice for him.
The mother of the dead 13-year-old victim said she wanted Mr Wanchai to ceremonially apologize to the spirit of her daughter. She brought a photograph of the girl to the court.
Police said Mr Wanchai, accused of raping and killing the victim, Nong Kaem, admitted to the crime. He reportedly had taken methamphetamine pills and drank on the train before raping the girl.
Mr Natthakon, who earlier admitted to acting as a lookout, is now denying involvement.
The two men are currently being detained at a prison in Prachuap Khiri Khan, where the girl's body was found after being thrown from their Bangkok-bound train from Surat Thani province.
Police charged Mr Wanchai with the rape and murder of an underage girl, hiding of a corpse, theft of the victim's mobile phone and possessing methamphetamines. Mr Natthakon faces a charge of abetting Mr Wanchai's crime.