Bangkok (CNN) -- The distraught mother of a 13-year-old girl raped and thrown from a sleeper train en route to Bangkok has told of her daughter's dreams for the future, amid angry calls for a mandatory death penalty for child rapists.
"She wanted to be an angel, she wanted to be an air hostess," her mother said of Nong Kaem. "If she was still here I would do everything to support her, but now I have nothing left."
Kaem's sister, one of two who was traveling with her on the overnight train from southern Thailand on Saturday, wrote on Facebook of her guilt at not being able to protect her. "Kaem, I am so sorry that I failed to look after you. I am a terrible sister. Please forgive me," she wrote, according to the Bangkok Post.
Journey turned to horror
It was Kaem's first time on a train.
She was returning from the city of Surat Thai with her two sisters and one of their boyfriends to the Thai capital Bangkok, a popular route for tourists going to and from the country's popular southern beaches.
They were sharing a sleeping carriage, and turned in for the night. By the morning Kaem was gone.
Police searched the train and the track as the teenager's frantic family turned to the media for help in finding her.
Three days later, her body was found naked near the track; she'd been raped, suffocated and tossed out of a window by her attacker who told police he had been drinking and was high on methamphetamine, according to Police Major General Thanet Soonthornsuk.
Tracked down by phone
Police named Kaem's alleged murderer as 22-year-old railway employee Wanchai Saengkhao.
They said he confessed to the crime after he was tracked down via his victim's mobile phone. Wanchai sold the girl's phone to a shop owner in Bangkok, who took a copy of his I.D. which was later passed to police.
Police said Wanchai admitted carrying the sleeping child to another carriage where he raped and strangled her, before throwing her lifeless body out the window as the train passed through the Pranburi District in Prachuabkirikan Province.
Wanchai has been charged with murder, rape of a child under 15 years old and theft, police said.
He faces possible execution for the murder charge, but activists are using the case to call for tougher charges for child rape, which currently carries a jail term of four to 20 years and a fine of up to 40,000 baht ($1,200).
Rage vented online
The reaction on social media was swift and scathing as angry Thais bombarded Wanchai's Facebook page with abusive messages. The page is no longer available.
Junta leader, army chief General Prayuth Chan-ocha, expressed his sorrow, and the former transport minister, Chatchart Sitthipan, said he took the blame for failing to do more when he was in charge of the railway.
"It is the worst news in many years for the State Railway of Thailand and the Ministry of Transport. I feel that I am also responsible for this event, because I did not do my job well enough when I was the Minister," Chatchart said.
As word spread that Kaem had gone missing, Thai actress and former Miss Thailand, Panadda Wongphudee, posted a message on Instagram urging people to back a campaign to change the law under the slogan, "Rape, will be executed."
A Change.org petition was set up calling for the tougher penalties -- "no more sentence reduction, parole or pardon" -- which at the time of writing had more than 25,000 signatories.
There were also calls for State Railway of Thailand governor Prapas Chongsanguan to step down, as officials scrambled to assure passengers the trains were safe. A ban would be slapped on the sale of alcohol on all trains, they said, and background checks would be stepped up for all employees.
Are new laws the answer?
Amid the anger, some called for calm.
"We have to listen to this news with full consciousness. To design or change a law base on emotions and hatred will never produce effective law. It will only promote more hatred in society," said Dejudom Krairit, Chairman of Lawyers Council of Thailand.
Writing in the Bangkok Post, columnist Sanitsuda Ekachai said: "I seriously doubt if the angry calls for the death penalty as the only punishment for child rapists and rapists/murderers will make our society any safer.
"These calls stem from the belief that this heinous crime was possible because the punishment is not heavy enough. This is not new. We hear such calls every time a shocking rape or murder happens."