DHARMAPURI: A youth, who came out of jail a few days ago after being arrested for threatening the public, murdered his mother during an argument between them at their house in Dharmapuri district on Thursday night. Police said the youth, S Devaraj, 20, of Palaya Indur murdered his mother, S Chinnapappa, 45, when she advised him to reform himself. Police arrested Devaraj on charges of murdering his mother.Dharmapuri district superintendent of police A K Arun Kabilan said Devaraj was earlier arrested on Aug 3 for threatening the public by wearing a police cap, brandishing a knife and trying to attack a man named Veeramani. The youth, who was lodged in Salem Central Jail under judicial custody, came out on bail on Oct 28.An argument broke out between the mother and the son at around 10.30pm on Thursday. “Preliminary inquiries indicated that Chinnapappa had questioned Devaraj about his behaviour and advised him to reform himself. This angered Devaraj, who suddenly attacked her with an iron rod, inflicting fatal injuries on her,” the SP said.Kabilan said, “Though reports had linked the incident to ganja consumption, no evidence has emerged that Devaraj was under the influence of ganja at the time of the murder.”