A three-member armed gang murdered A. Prabhu (25) and assaulted his father Annadurai (48) at at Pudhu Mariamman koil Street at Thennur here on Sunday. S. Raja (27) A. Pandiarajan (22) and M. Dinesh Kumar (22) have been detained. Police said Raja and Prabhu had a brawl at a liquor shop a few days ago. Raja who bore a grudge against Prabhu allegedly committed the crime. Prabhu’s father Annadurai is the cadre wing district Secretary of Puthiya Tamizhagam.