CSD Commander Pol Maj General Sapphuang Suthin said they were hoping to find additional evidence, such as bloodstained clothes, in Dechathorn Mulsri’s apartment, on Soi Charansanidwong 65 in Bang Plat district.
Forensic officers collected samples from the room, which was said to be in a tidy condition, to look for evidence.
The apartment caretaker told police that Dechathorn had rented the room along with friends in 2015. Other tenants said it was frequented by visitors who often made noise.
Thirapong Thitatharn was killed in his dormitory at the university last month after about 20 assailants burst into his room.