Dehradun, Oct. 7 -- A plumber was arrested on Tuesday for allegedly killing an elderly couple and a domestic help with a screwdriver following an argument over payment for his service in Vishnu Lok Colony of Dehradun district, police said. The accused, Raj Kumar, is a native of Bijnor in UP. The deceased were Rajni Kapoor, 75, and her husband Ramesh Kapoor, 80, and Tiliya Devi alias Sheela, 48, a domestic help. Police said the incident took place on Tuesday between 2.30pm and 3pm. SSP Dehradun Pramendra Dobhal said, "During questioning, Raj Kumar told police that he had gone to couple's house in the afternoon on their call to carry out plumbing work. After completing the work, an argument broke out over payment made to him. He attacked the couple with a screwdriver." He attacked Sheela too when she tried to intervene, he said.htc...