Police have arrested a 32-year-old suspect, who was caught on camera committing the assault and loading the victim onto a motorcycle sidecar before fleeing, reports the Bangkok Post.
Boonyu Samjai was walking for exercise along Soi Nak Prasit in tambon Thung Nonsi around 5:30pm on Tuesday when he was approached by a man riding a Honda PCX motorcycle.
Police said the man, later identified as Withawat “Mos” Tanghu, confronted Mr Boonyu before a brief argument escalated into violence. CCTV shows the suspect punching the victim before seizing a wooden stick and repeatedly striking him over the head.
When bystanders attempted to intervene, the assault continued.
Police said the suspect briefly rode away before returning with a bamboo pole, which he used to strike the victim several more times as the elderly man lay motionless on the ground.
Investigators said the suspect then drove to his nearby durian orchard, returned in a blue motorcycle sidecar, loaded the unconscious victim onto the vehicle and drove away.
Police, local officials and rescue workers responded to reports of the attack, but both men had disappeared before they arrived.
Officers later searched the suspect’s orchard, about 750 metres from the scene, where they found bloodstains, a handgun and a shotgun, but no sign of the victim.
Rescue divers were also called in to search a nearby pond after investigators suspected the victim’s body might have been disposed of there.
Following a manhunt that lasted several hours, police arrested Withawat at 11:05pm on Tuesday at a house near Wat Bamron in Muang district.
During questioning at the Khao Saming police station, the suspect denied disposing of the victim’s body, claiming instead that Boonyu had jumped from the sidecar.
Investigators said he gave inconsistent statements and refused to reveal where he had abandoned the vehicle.
At 10:10am yesterday, police found Boonyu’s naked body in a rubber plantation in Moo 3 of tambon Thung Nonsi, about 1.8km from the scene of the assault.
The area was sealed off for forensic examination before the body was sent for an autopsy.
Authorities later recovered the submerged sidecar from the Ta Kad reservoir in neighbouring Huai Raeng subdistrict, about 5.8km from where the body was found.
Investigators also seized a blue plastic container found in the vehicle as evidence. Police are examining whether it was used to transport the body but have not reached any conclusions.
Ratsami Samjai, the victim’s 55-year-old sister, said her brother had moved to the area less than a year ago. He used to go out regularly for exercise and never knew the suspect, she said.
According to the family, the suspect confronted Boonyu by asking why he was looking at him before launching the attack.
“I want the perpetrator to face the consequences of what he has done,” said Ms Ratsami.
A local resident told reporters he had unknowingly helped the suspect escape on Tuesday night after encountering a man soaked from head to toe who claimed his vehicle had run out of fuel.
Believing he needed assistance, the resident gave him a ride to a friend’s house several kilometres away, only realising later that the passenger was the man police were searching for.
Village headman Phongsan Kruapinchai said investigators later followed tracks leading to the reservoir, where divers recovered the submerged sidecar.
He said the suspect had slipped through a police checkpoint during the search by riding in a local resident’s sidecar, as officers did not recognise him because they had never seen him before.
Police are continuing to investigate the motive for the attack. Investigators are looking into reports indicating the suspect had a history of involvement with drugs.