On January 31 this year, Pham Tuan, 30, saw a 21-year-old epileptic who begged for a living, near his house and tried to rape her on the street in the central province, the prosecution said.
She resisted, had an epileptic fit and passed out. Tuan stole VND120,000 ($5) from her and threw her into a river fearing she would complain to the police if she came to.
But he left behind his footwear and a stolen phone at the scene.
When the woman did not return home that night, her parents went to the police, who found the two pieces of evidence at the scene and linked them with Tuan.
The woman's body was found three days later, six kilometers away from where she was last seen.
Tuan also received seven-year imprisonment for robbery.