Thirapong Thitatharn, a senior at Silpakorn university’s Phetcha-buri campus, died in hospital on March 2 and two other students were injured in the attack.

Thirapong’s mother, who took her son’s body for a funeral in their hometown Chumphon, promised to press charges and expressed concern that justice might not be served as some of the assailants were sons of local politicians and police officers.

Based on forensic evidence and security camera footage, police secured arrest warrants for 18 suspects. Cha-am police superintendent Pol Colonel Pakin Sivamethakul said previously that 16 suspects had already surrendered to police while two remained at large.

Thirapong’s relatives said they believed the person responsible for Thirapong’s death was not among the 18 suspects. They said they would not cremate Thirapong until the investigation had progressed.

Phetchaburi police chief Pol Maj-General Surapong Chaichan said police would summon the 18 suspects for additional questioning before submitting them for prosecution. He assured Thirapong’s relatives that police would investigate the case honestly.

Thirapong’s wounded friends have also filed a police complaint at the Cha-am precinct bringing attempted murder charges against the 18 suspects.

One of the injured students said that between 15 and 20 assailants arrived at the dormitory in three cars at 1am. The occupants of two of the cars entered the dorm, while the occupants of the third car waited in front of the dorm.

When one of his roommates opened the door he was hit in the head by a bottle and stabbed in the arm with a broken bottle, the student said. His other friend was stabbed with a 20-centimetre-long screwdriver in his face.

The student said one assailant stabbed Thirapong in the back of the head with a screwdriver, which broke off from its handle and stuck in his skull, while other attackers kicked him, sending the screwdriver in deeper.