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, 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.htc...