Sirimongkol Reunnak, 33, was arrested on Friday night in Buri Ram while he was riding a motorcycle along with his wife and daughter towards Surin.

He denied rape but admitted robbing and stabbing to death the student because she fought back, police said.

Sirimongkol told police that he had been drinking with his brother before he grabbed his brother's motorcycle taxi waistcoat so that he could work for money to buy more alcohol. He then picked up the girl, who was waiting for a taxi at Niwet Chaofa Village, and took her to the back yard of a housing estate to rob her. Doctors found multiple knife wounds and evidence of sexual assault on the victim's body, said Metropolitan Police Area 2 commander Maj-General Amnuay Nimmano.

He said Sirimongkol had been previously charged with raping his wife's sister and had a history of drug abuse causing him once to be admitted to Srithanya Psychiatric Hospital.

Amnuay thanked civilians who had provided information leading to the swift arrest.

Police yesterday took Sirimongkol to re-enact his crime at the scene, but 300 angry onlookers tried to attack the suspect, forcing police to cancel the plan.

The victim's 45-year-old mother, a food-vendor, said her daughter had been serving drinks at the funeral of a friend's relative until almost midnight on Thursday and had phoned to say she would be home soon but had never arrived, prompting the family to look for her. Her body was later discovered by a construction worker.

The victim was a good, obedient and intelligent girl and her mother had raised her and her younger brother after her father died of kidney disease eight years ago, according to the girl's aunt.