A gunman or gunmen blasted Id Chaisith, 74, as he walked home from praying at a shorefront mosque in Kalim, north of Patong, about 2pm.
He was hit by five bullets in the groin and torso, investigating officer said. Khun Id died later in Patong Hospital.
''We only have one motive, and that is over a side soi about a block back from the beachfront,'' an officer said.
''Khun Id claimed that he owned a narrow roadway. Others were not happy. That is our first line of investigation.''