A man was arrested after a monk was punched in the face and died in Hang Dong district of this northern province on Saturday, Chiang Mai News reported.
Pol Lt Col Thongchai Uathae, a Hang Dong police investigator, said the incident occurred at about 4pm at a temple in the district.
He identified the suspected killer as Den Lamnai, 44. He was arrested shortly after the monk, Phra Somboon Suriyamai, 60, was pronounced dead.
Asked what led him to attack the monk, Mr Den said Phra Somboon hit him first, and he punched the monk hard on the jaw in self-defence.
After Phra Somboon fell to the ground, the attacker said he prostrated himself to plead for forgiveness and walked away from the temple. He found out later that Phra Somboon had died, he said.
A neighbour who wished to remain anonymous told the Bangkok Post that the altercation actually occurred much earlier, and began after Mr Den used a stick to fend off several dogs that lived near the temple, Wat Doi Gu Kham, at around 9am on Saturday.
After Phra Somboon admonished him for using the stick, Mr Den, who was drunk, punched him in the face, causing him to fall backwards and hit his head on a metal rail at the main entrance.
The neighbour said Mr Den, known as Nai Ot, confessed he had accidentally killed the monk to several people in the area and then went to tell his family.
They asked him to leave the house, and he was arrested within the hour near Grand Canyon Water Park.
The Bangkok Post was not immediately able to corroborate the neighbour’s account.
According to the neighbour, Phra Somboon knew Mr Den and had previously given him food, since he appeared to be living in the nearby forest after becoming estranged from his family.
The neighbour described the monk as “a very gentle and friendly person, always raking the leaves around the grounds as he was doing when he was killed.”
Mr Den was initially charged with physical assault causing death.