A 21-year-old motorcyclist captured on video punching and kicking a middle-aged man to death surrendered to police on Friday.
Kritsana Puithong admitted to assaulting Wichai Chaitrakul, 51, in a fit of anger after the man scolded him for having his headlight on highbeam, Pol Col Charnnarong Samranjai, a senior investigator at Kabin Buri police station said.
Wichai later died in hospital.
The suspect, accompanied by his father, turned himself in to police around noon on Friday. He has been charged with murder and was later taken to the scene to re-enact the crime.
Wichai's relatives went to police in Kabin Buri district early today to lodge a complaint to arrest the suspect in the May 5 attack.
Video of the fatal attack was uploaded to Facebook at 12.40am on Friday and has since gone viral.
The clip shows the young motorcyclist violently assaulting the 51-year-old in full view of two women, who were pillion passengers, in front of Kabin Buri train station between 3am and 4am Tuesday.
The two men were seen with their motobikes parked closely together and exchanging heated words. Then one got off his motorcycle and punched the other man in the face, sending him to the ground. The attacker then repeatedly kicked the fallen man as his girl friend tried in vain to stop him.
The assailant and the girl fled on their motorcycle as a garbage truck arrived. Rescue workers rushed to the scene and immediately sent the seriously injured victim to a nearby hospital, where he died shortly after.