Rawiwan Puangthong, a second-year student at Rajabhat Walai-alongkorn University, was found strangled to death in her apartment in Khlong Luang district on Friday.
She had a cut on her chin and a blanket wrapped around her face. Her hands were bound with a cord.
Investigators examined CCTV footage outside the building at the suspected time of the murder. They found footage of Nattakorn Kamnula, 27, a native of Surin outside the building.
Mr Nattakorn, who investigators said appeared agitated and had fresh scratches all over his body, allegedly confessed that he had climbed into the victim's room on the third floor through the unlocked balcony door to steal her underwear.
Mr Nattakorn said the victim was in the room sleeping at the time but woke up when he entered the apartment.
He told police that he punched Rawiwan several times as she shouted for help and pinned her to the floor in an attempt to quiet her. She fought back so he hit her with a bottle, he said.
He then put underwear in her mouth and strangled her with a bra, then tied her hands with the cord.
The suspect said he took her purse and mobile phone and climbed back out the balcony door. He sold the phone for 13,000 baht.
Police said the suspect admitted that he broke into another apartment on Feb 5 and stole some valuables.
Read the original story on the Bangkok Post here.