The case also raised questions about the safety of Thailand's long-distance trains, which are popular with tourists who visit the country's southern beaches and enjoy jungle treks in the north. As a result of the July attack, the State Railway of Thailand introduced special carriages for women and children for overnight trains on main routes.

The attacker, 22-year-old Wanchai Saengkhao, was a temporary train employee whose job it was to make beds in the sleeper cars. He confessed to drinking beer with his colleagues and taking drugs during his shift on the night of the attack and then raping the girl, who was sleeping in a lower bunk during a trip to Bangkok.

The Hua Hin provincial court on Tuesday convicted Wanchai of murder, raping a minor, concealing the body to hide the cause of death and other charges. It said Wanchai's crimes were "outrageous," ''inhumane" and "could have an impact on society's order."

The girl was traveling with two of her sisters from their home in southern Thailand to the capital on their first solo train journey. When the sisters, ages 22 and 10, awoke in nearby beds, they found their 13-year-old sibling missing, and a nationwide manhunt began.

During a reenactment of the crime, Wanchai told police that he smothered the girl and then threw her body out of the moving train. Her naked body was found three days after the murder in bushes alongside train tracks in western Thailand.

"The behavior in this case was serious and, therefore, deserves severe punishment," the judge said in the verdict.

Capital punishment is the maximum penalty for murder in Thailand, and rape is punishable by four to 20 years in prison.

The court also sentenced a 19-year-old train employee to four years in jail for aiding Wanchai with the rape.

Family members of the victim attended the ruling, wearing black shirts that called for capital punishment for rapists.

"Those who committed the crime must be punished for what they did. The court has given us justice," said Pattanachai Thaninpong, 35, a cousin of the victim.

The military junta that took power from a civilian government in a May 22 coup dismissed the governor of the State Railway of Thailand after the attack.